1974 Ford Capri, the evolution of 20 years

Thanks. Patience or just some strange addiction, I'm not sure...

After some driving and adjusting during the summer I finally got the Capri on the dyno at Sävar Motor again.

Short spec:

205 Pinto block
DP Pistons in 91,5 mm bore, 38 mm flat tops
Maxspeedingrods steel rods, 129,5 mm
 (should give me around 8.55:1 CR)
RWD YB oil pump and spray bar
YB sump with wings, and trap doors
Pinto crank
TTV steel flywheel to take 240 mm YB clutch

Head is a carb Pinto head with slight port job
Paul Ivey/REC valves (REC 882 inlets 1.800”/45.7mm, REC 297 exhaust1.500”/38.0mm)
Kent FR34 camshaft (the kit with supplied springs etc. from Kent Cams)

"Swedish plenum" intake, YB trumpets fixed to Pinto flange
Pulse split exhaust manifold

Mitsubishi TD04-19T turbo, internal wastegate (modified Holset actuator)

Megasquirt MS3 with MS3X board. MAC valve boost control.

While the engine had been reasonably responsive during the summer, at around 1,4 bar, it was evident some real dyno tuning was needed.

We started off at spring pressure (no boost control activated) and that leveled out at close to 1.1 bar. At around 6500 rpm the power was still climbing but just over 7000 we heard a clatter in the knock sensing equipment. We figured it might be valve float or possibly the rather aggressive ramps that made the sound.  Another 500 rpm would have been nice but not this time.

The baseline ended up at 245 whp (6900 rpm) and 273 Nm (5800 rpm), not a bad number and quite perfect for registration purposes.

After that, we enabled the boost control and started to dial in more boost for track use. This is my first try with a real boost control system, and that was quite interesting. At around 1.5-1.6 bar the turbo stopped flowing more in the higher rev range so we decided to ramp down the boost towards 7000, and instead kick it up a bit until 4500-5000.

This gave a max power of 279 whp (5800 rpm) and 416 Nm (4400 rpm).

Now for the interesting part, comparing to the old engine specification (lower compression ratio, smaller head/valve/cam, bigger Holset HX35 turbo).

When we tuned that in 2015 the top results were 284 whp (5900 rpm) and 398 Nm (4400 rpm), at 1.8 bar. At 1.1 bar that engine gave 226 whp (5900 rpm) and 325 Nm (4500 rpm).

Dyno graphs:

(New engine)

(Old engine)

I do think I now have an engine with a broader power band. Barely had time to drive it before the winter though.

So, onto the diff/axle "solution".

Back in 2016 I snapped one of my specially made steel drive shafts (or, if the CV joint broke first and then snapped the shaft?). I got a used standard drive shaft from a Sierra just to get the car going. But the sensible thing was not to just replace with the same parts over again, but instead to upgrade. The rear suspension is based on a Sierra XR4x4 so it has the 7" diff and the smaller "100 mm" CV joints.

I started working on getting the bigger "108 mm" CV joints instead, together with thicker drive shafts. These usually do not "fit" my Quaife differential, but luckily Quaife will do stub shafts for the bigger CV joints. Just a credit card away...

Then I had to get the outboard stub axles as well. I found an E-bay company selling new ones but when they arrived I really did not trust them. They have some play in the splines for the hubs - probably a non-issue on a standard car but with over 400 Nm, no. Instead I raided a friends stockpile of old Scorpio parts, he had just parted out a Scorpio V6 estate and that one has the big CV joints. Good find.

I had already ordered new steel drive shafts to suit, and also got some new SKF CV joints at a discounted price. Still I hesitate to sum up the cost of this rear end!

New CV joints fitted...

...and the completed shaft.

All fitted up, hard to see, and looks just like before. But the shafts are thicker and everything is just beefier. If it breaks again...well...I don't know what to do. Or maybe I do, I guess then it is time for a completely different approach. But this should work (famous last words!).

Gustaf

I love this thread.  what a cool car!

before anyone wigs out about Power and Torque not crossing at 5252 rpm, please note that the units of TQ are Newton-meters, not Pound-feet.

Thanks!

The latest thing I have done this winter is kind of a stupid project, you know the small things that take a disproportionate amount of time, with results that are barely noticeable for most people. Well we GRM'ers are not most people.

Ever since I got the car together in 2014 I have been annoyed that the blade anti roll bar and the tension struts limited steering angle. Back then I saw no good solution but that matured over time.

So I used up more hours than I like to count, on shortening the tube for the ARB, and moving the mounts for the tension struts.

Great on one side, not so great on the other since the steering rack seems to be off center. I need to measure that up. I need lock stops on one side, not on the other.

Hopefully it is just the rack that is slightly off center and adjustments can be made. For the time being, the locking collar on the rack is still needed:

This is my preferred method to stop rubbing, a lock collar on the rack itself.

Now I have one big thing to think about, and that is gearbox(es). I run a WC T5 from a Sierra Cosworth rwd, and it has started acting up, When cold, getting second gear is almost impossible without double clutching. Warm it works OK. It got new oil last summer, ATF Dexron III, no change. 

At  416 Nm (306 lb fts) the T5 is just at its specced max torque. I do suspect though that a shift fork may be bent (despite using a Steeda Tri-Ax shifter that is supposed to avoid that). But what do I do?

A standard rebuilt T5 seems like a no-good option, it may (will?) fail again. Gearboxman/Quaife in the UK has a heavy duty kit with strenghtened forks, that is the "easy" solution at something like 2500-3000 USD (fitted in my 'box). A Tremec TKO 600 is in the same region, a lot stronger, but also larger (may not fit the tunnel). It also means new clutch and propshaft since the splines differ.

Both of these (T5 and TKO) are not known for shifting well above say 6000 rpm.

Everybody else in Sweden cuts and shuts BMW (ZF or Getrag) gearboxes, but I am not really a fan of welding an alloy bellhousing. Plus, if that gearbox brakes down, you need to weld again = downtime. A bolted adapter plate may be an option. Again, new clutch and prop. So even if the gearbox itself is cheaper (say 1000-1500 USD for a completed kit) it's not that much cheaper than the T5 gearkit (and that will be new!).

So, motorsport gearboxes. Of course, the sky is the limit but keeping it at tree tops level, there is the Elite IL300 6S. rated at 540 Nm is should be OK, and it's sexyquential. Sexyquential! With Ford type 9 form factor for bellhousing etc. its a rather easy fit. But it's a close ratio 6-speed, I really don't need that with the turbo engine. Price is around twice of the T5 gearkit. Not unreachable but a reasonable chunk of money. And service life of a motorsport gearbox on the street is an unknown.

This merits some thought...

Gustaf

Gearbox choice is still out there. Sort of leaning towards a gear kit for the T5 but the supplier won't answer my e-mails, that annoys me. This morning a stop-gap option was discovered, there is a version of the late Scorpio that has an MT-75 gearbox that may almost bolt in. A bit of an unknown since "nobody" has tried 400 Nm through it but rated at 300 Nm by Ford, it is only about 35% over spec. I have done worse and the gearbox should be available for a couple of hundred dollars.

The spring is hopefully only something like a month and a half away so any big stuff will wait I think. Not wanting to waste some "free" garage hours I have been tinkering with small things.

Yesterday I adjusted front wheel bearings. Today I tackled some things that I never seemed to get time for - the things that only take minutes once you start.

First off was the tailgate inner panel. The grp tailgate is solid so it has been low priority:

Doesn't look too bad but since I had a decent stock panel...

Better! Fitted with double sided tape so I didn't have to drill holes for the plastic panel clips that always break.

Next up, the gas cap lid. The painter forgot it when the car was being painted, so I took another one I had and just wrapped it in carbon fibre effect vinyl when I assembled the car in 2014. Well now I thought it was time for a body coloured panel...

And, onto the last fix for today. Ever since I got the black Recaro seats (must have been 2003-2004) the cable for releasing the seat back on the passenger side has been broken. You had to reach down to the hinge and release it. With no rear seat now, it should not be a big deal. But, the space where the rear seat used to be is a handy place to put stuff. And the driver seat is fixed. So it is an annoyance.

I have been putting off fixing it since I thought I needed to strip the entire seat back. Turned out I could splice the cable (I think...) and do it from the outside. 

So three small fixes that hopefully makes a difference - at least in my mind. And that's sort of where it counts.

Gustaf

The gearbox roulette turned towards a T5 gearkit after all, so it was ordered and a rebuild kit sorted. An added bonus was that I "had to" get a 20 ton hydraulic press, something I have wanted for years.

I also took delivery of my QuickJack set. Another "wanted for years" thing.

With all that settled last night I finally took the gearbox down. With the quickjack and a big floor jack turned into transmission jack it was quite quick work.

What's worse than tearing down a broken gearbox?

Perhaps tearing down a gearbox where everything looks great?

I haven't gotten the gear clusters out yet but from what I can see everything looks just fine. No real explanation for the issues going down into second gear when cold. Might be a clutch issue...

Anyway, the plunge is taken and I will (I think...) put the new gearkit into this one. My old parts can maybe be used to rebuild another gearbox.

Gustaf

Seeing this on Page 1 makes me happy.  Great work so far!  I really dig this car.

Thanks!

It hasn't been driven much at all (or worked on) this year, mostly because of too much work and other things happening in life.

Yesterday night after helping a friend with his Zetec turbo Westfield I took more of the gearbox apart and it still looks very nice inside. I really can see no reason for it to behave like it has done but I hope that a generous amount of money and time thrown at it will help :-)

Gustaf

Neither time nor money has proved to be the solution - yet.

The gearbox is in the car, I guess it was driveable around July 2nd or 3rd or something like that.

It was not without issues though, Gearboxman sent the wrong 5th gear so I had to wait for the correct one to arrive.

And then, test drive - and the same issue is still there! Not a happy camper. I have tried several things by now and the two remaining options I see are the clutch pressure plate or the 1st/2nd syncro hub sliding sleeve. But that will have to wait until later.

I will get it sorted one way or the other, I am also on the lookout for another T5 to rebuild with my standard parts, just new bearings, synchros etc. Then I can swap boxes around until I find the fault.

The decision to drive the car as it is now for the summer was made, mostly because we had the annual week in Lycksele coming up and I hate being there with no fun car. This is an entire week plus weekend (so 8-9 days) where the small town (population of 8500 persons) hosts a series of motor events. I guess there are something like 20-30 000 people visiting the place.

We usually go there with the camper together with some friends and I try to use the Capri where I can, some shows and also the drifting 

This year my wife had to drive the Capri to the event. We have bought a new camper/caravan and she needs an upgrade to her license to tow it. Now, with the new clutch the car is reasonably easy to drive, but still a bit away from the Capri 2.0S she dailied a while many years ago. But she set off in the heat (30 degrees C all week). 

My first event was the classic car show, a show that really focuses on "stock" classics but also invites modified cars.
(all photos below are from the event site, https://www.flickr.com/photos/motorveckan/collections/72157667405626557/ all rights to them)

Rolling in to the show grounds.

This year I managed to get a spot next to the other Capri. There are so few of us here, that we need to stick together! His car is a mostly stock MkIII 2.0 GL, but it has a turbo tail, Taunus/Cortina alloys and a black bonnet - it is also resprayed in a burgundy kind of colour.

The Saturday is a bit hectic for me since the classic show collides with the drifting event, so I had to leave early in time for tech inspection and the other things you need to do. I had found some new drift wheels, some Fondmetal 7x15's in the style I have liked since 1999 when we celebrated the 30th birthday of the Capri (at a camp site named "Capri" on the west coast of Sweden). These were found semi-locally at a good price so I couldn't let them go. Plus, they were fitted with decent rubber for drifting, 195/50-15 so they shouldn't be too grippy.

I drove off to the airport (where we drift) and filled up with some fresh 98 octane on the way. Because of the heat I had turned down maximum boost a bit, I had no intention on blowing the engine 2 hours from home with no trailer.

First practice round felt decent, although I was a bit unfamiliar with my new helmet and the Simpson Sport Hybrid neck restraint. Next round went a lot better and I actually felt rather confident. Make no mistake, neither me nor the car is a proper drifter compared to the other guys, but I had great fun.

Scoring points in drifting is sort of a difficult thing, especially perhaps on this track since all of the outboard drift zones are marked with really hard and heavy cones - not something I would want my X-pack arches to get too friendly with! There are 5 zones and each zone can give you 20 points, so the total possible maximum is 100 points for a round. A spin or stop is an automatic 0.

Last year I scored my first points (2). This year I made 10 points in the first round, so the improvement is fast  Second qualifying round was not as good with 5 points. We only got two rounds since we had a firm time we needed to evacuate the air field. Something about airplanes having to land or similar.

Anyway, the TQ in my class made 64 points and in the pro class there was an outstanding 94.

In the elimination I was facing a 600-something whp BMW e46, and although he did not make a perfect run I made some mistakes and had to watch the rest of the competition from the side. Still fun and I got to see my pal Basmange win, in his mostly stock Sierra 2.9. 
 

The video:

https://youtu.be/2AuiTa_l5Ic

All in all, a good week!

Gustaf

Distraction is a killer! 

No reports on the Capri at all from 2019, that's a bit sad. And I even didn't really finish describing 2018.

One of the issues I have had with this car since the first gearbox swap back in 1998 (I think, must have been) is speedometer accuracy. After swapping speedo driven gears in the old Type 9's and still not getting it right I opted for a bike speedo for years. That one actually worked well, but when I rebuilt the car back in 2010-2014 I deemed that it was not the right look. The T5 gearbox was no better but I made a new dial face trying to correct it. No joy, and then I converted a Scorpio electronic speedo instead. That sort of worked but the scale was still not really correct and the needle kept on sticking.

In 2018 I did what I should have done years ago, bit the bullet and ordered a SpeedHut speedo. It is nicely dissassemblyable (!) so it can fit in an almost un-modified Capri cluster. And the font almost matches what I already had.

I should have remembered to order one with the programming button at the back though :-( After connecting it right - it works brilliantly well. So well that I feel my next Capri project probably will have a full set of SpeedHut gauges in a stock cluster. There goes another princely sum of hard earned money...

Not much else happened in 2018 (for Sierra reasons) and it felt a bit strange to take the car out in 2019 with no real changes made. Actually it didn't even come home to my house from the winter garage until vacation time, meaning June in Sweden.

I did decide to go out on some drifting practice, on the local rallycross track. The drift section is quite nice itself but the kerbs are scary and someone has placed a really large Capri-magnet in the sand trap. I ended up there on both practice sessions in 2019. A sand trap sounds OK but this one has some rather large rocks and stuff so it's really not a place to be. Thankfully I reversed into it both times. There are some battle scars on the sills but it's not too bad. On a side note - I see drift tracks becoming less and less "car friendly" with walls, rough run-off areas and stuff like that. It is what is gonna drive me away from using this car in that way, the punishment for a mistake is just too hard. And then organizers moan about people only arriving in "drift missiles" and no new drivers coming in. Go figure.

Still, the drifting at Motorveckan is on the airfield, with only cones (albeit big ones) to run into. 2019 saw me make a new personal best, 33 points in the second qualification run. As always, the practice runs were better :-) Elimination once again saw me face a BMW, and, as always, I lost ;-) 

Sometime after that I also swapped in one of my old exhaust manifolds, a "short" one, trying to get more low range power. But the difference was not noticable at all. But I had to try it.

Oh, and Motorveckan also scored me a spare T5 gearbox. It has been (ab)used in rallycross but should at least help me isolate my shifting problems. Whenever I get the urge to try :-)

With the Capri tucked away for winter and work intensifying on the Sierra, I could not keep my mind off the turbo lag situation. I really, really want the car to have more low end punch. Or at least mid range. E85 is probably one possible solution but my mind also went towards more modern turbochargers and ball bearings. The TD04-19T I had is still 20 years old in design...

Borg Warner makes some really cool spinny things and their MatchBot calculator is addictive. I had almost stretched my imaginary (!) budget limit to account for a $2000+ turbo when a drifting friend approached me for other reasons. He is working with Kinugawa turbos and offered one of their new charges for a bit less. Somewhat a gamble but he also knows my car and has used Kinugawa stuff on his cars.

This is a ball bearing TD05H-16KX (yes, they are "Mitsubishi inspired" turbochargers) and it will be very interesting to see what it will do.

That's how 2019 ended, at least :-)

Gustaf

YESSSSS!

:-)

One of the nice things about the Kinugawa is that the form factor is very much the same as the 19T I have been running. "Bolt on" almost... Until one of my old car builder friends called and was bored. He sold his Westfield Zetec turbo just months after completing it, and bought a bike instead. But now he wanted something to fabricate and thought that a new manifold for my new turbo would be fun.

Of course I said go ahead. The short manifold I swapped to during 2019 was a pig to fit but I still wanted a shorter manifold for an internal wastegate turbo.

He worked away rather quickly while I was busy with the Sierra.

Soon we could make a trial fit.

Looks pretty good but "bolt on", nah. Not so much anymore.

This was probably February or something and ideally the turbo swap would have been done by April. It didn't happen...I only started building the downpipe adapter and the oil lines a couple of days ago.

Checking for bonnet (hood?) clearance with the cell phone on timer-shoot. Tight, I would have prefered the manifold to be 1/2" lower but hey... A torque strut on the engine, a turbo blanket and I think it will be fine.

The big issue here is that the car is still in the winter garage, where I have no tools. So I spot weld something, drive 10 minutes to garage, test fit and go back home to alter. Now in round 3 or 4 and counting :-) I could pull the car home on the trailer but...

Gustaf

Great to read more updates.

Nice to see progress with this.

Your mounting here makes the turbo easy to access unlike the stock Mazdaspeed Miata manifold.  It's better to just remove the whole manifold with that, but I wouldn't call doing so easy.

In reply to trucke :

Had a 76 back in 1987 2.8 liter 4 speed. Fun car, but had front suspension issues. 

Yes, I like having a "top mounted" turbo for many reasons but it also makes some things a bit more complex.

Right now I have issues fitting the downpipe, I may have to resort to modifying it more. Original plan was to be able to leave it pretty much as it was. Guess not.

The Capri front suspension is somewhat a mess, much as the MkI Escort it is firmly based on. To be honest, it has the components that could make it work (nice rack and pinion, quite beefy struts, detachable steering arms) but Ford just made most things slighty "wrong". Not enough KPI so there is massive scrub radius, not enough positive caster so it tramlines, not enough negative camber or camber compensation, no adjustability except from toe.

Gustaf

Towards the end of the summer the manifold was finally welded and fitted for a test start. I made the tactical mistake of not bringing the car back home from storage to do this ("it's just a matter of fitting some stuff" - I have no tools there so every wrenching pass was a fight).

And then I realized that the turbo did sit too high after all. Tomas offered to build a new manifold but I just did some pie cuts and changed the angle. Never let perfection get in the way of completion?

Some time around late September or early October the car was actually ready to drive. But also pretty much blocked in at the storage garage. I felt 2020 was a lost year. It even started snowing.

But then the snow melted and the sun came out. What if...?

Bonus pictures of the new trailer, by the way. A dream to use, and, it is British!

I have test driven a bit during the weekend and it feels pretty much OK but the car needs a proper mapping, especially the boost control. I have to reconfigure to use the dual port wastegate correctly and see what happens. I'm doubtful I can do that and test drive this autumn but we'll see. Actually the forecasts give me two more days of clear skies.

Slowly I am beginning to realize that I may have to give up on two things, after all. One is leaving my firm desire to run petrol, and switch to E85. The other is to leave Megasquirt. Not that it doesn't work, the one (MS3X) I have now in the car runs very good. But I have a MaxxEcu Sport that I got for the Sierra, and when going for the E85 flex fuel sensor, a more powerful ignition system and larger injectors I might as way go all the way. There are parts for an E-throttle conversion as well but I am not convinced that is worth the work...

Then I have the gearbox problem to sort. I have a new clutch ready to go in and also a spare T5 to try. So, the Capri will stay in the home garage this winter.

The race-Primera will be in the storage place with the added bonus of enough space to work on it there if need be.  I'll just not think about the fact I am paying for more space than I actually use.

Gustaf

A couple of nights ago I re-did the downpipe and fiddled a bit with the crank sensor.

I have pre-booked a time slot at my new, very local, hub dyno next week. Maybe a waste of money but I would like a base line on the boost curve and power with this turbo before going E85 and new management. The roads are far to wet and cold to be able to test drive in a safe manner, so...I see it as research, and investment in safety.

Wisely, I test started last night and that was a disaster. No, not really, given the times we are in but it didn't work as planned.

The crank sensor has had a slight misalignment vs the toothed trigger wheel, ever since I swapped to the Fluidamper. I blame the inability to rev past 6000 rpm on that, since it seems the rpm signal disappears. On the dyno in 2017 I had the old crank pulley where alignment was better and then it would rev cleanly to 7000. So I took things apart and fiddled, got better alignment but had to space the crank sensor a bit further out.

It started fine but soon lost signal. I had to make another shim to place it 0,5 mm closer to the trigger wheel. Then it works.

This makes me think...I use a YB crank sensor, made for the 4 tooth YB trigger wheel, but I have a 36-1 trigger wheel. Maybe the sensor doesn't like that many trigger points. I may need to revisit this and go back to a Zetec crank trigger, perhaps.

Gustaf

It's quite nice to have the car at home :-)

Yesterday I double checked the EPAS since I thought it felt a bit heavy to steer. Someway I had reversed the wiring on the main switch for the EPAS. On was off and off was on ;-) Must have happened when I took it out to fix a boost gauge or something.

Then I saw the shifter gaiter looking a bit sorry for itself. I knew we had a couple laying around from when we raided the junkyard for gaiters to fit the Sierra. So now the Capri has a nice, rip-free leather boot. Nice!

Gustaf

In preparation for the dyno slot, I had some dialogue with the guy who sold me the turbo, who is also a bit of a professor type with regards to engine design. Just like me, he had the feeling that my engine should be able to spool the turbo quicker. He had a number of ideas, some demanding more changes than others.

But he pinpointed one thing that was planned when the engine was first built but then I sort of forgot. Cam timing... We planned to play with it already on the dyno back in 2017, but ran out of time. It was setup according to specification back then. But I also read more and noted that it is not uncommon for the Pinto cam timing to move a bit as the belt stretches. Never thought of that.

So, a check was in order. The specifications say to have the inlet valve 2.95 mm open at TDC. That's where I set it but now it was only open 1 mm... So it had retarded itself.

My professor advised me to try advancing the cam from specified position, as that generally helps midrange. Encouraged by some tests David Vizard had made, I marked the pulley for 5 and 10 degrees advance, checked to see that it all should work and then reset the cam timing to specifications again.

Up until now we had a rather nice fall, no snow and dry(ish) roads. But the same day the dyno was booked...

Snow! I quickly decided that driving to the dyno was out of the question, so the trailer came in handy again.

We started with some baseline pulls with the boost control deactivated, to establish how it all worked. We could spot that the corrected cam timing made some slight fuelling adjustments necessary, and also that the turbo probably spooled a bit better. With no boost control the spring pressure was enough for around 0,7 bar and that gave around 175 wph and just under 225 Nm. Pretty much as expected.

Then we advanced the cam 5 degrees to see what would happen. Results shown were interesting! The dyno MAP sensor showed an increase in boost pressure already at 2500 rpm (from basically nothing to 0,2 bar) but the real change was that the entire boost curve came almost 700 rpm earlier. This gave a strange torque peak of over 250 Nm at 4000 rpm. But it also increased max power to just under 200 wph and lifted the entire torque curve. 

So it seems that advancing the cam was a good thing to do. Alas, we tried another 2 degrees but that just lost power and torque. It seems, according to this dyno, that 5 degrees advanced is a sweet spot.

The next step was to activate boost control and see what would happen with more boost. I lazily just used the old boost control settings, knowing that ideally they would need tweaking to be perfect with this turbo. 

As expected, midrange boost was only marginally improved (0,5 bar at just under 3500 rpm) and max boost (1,7 bar) at 4500 rpm. Driven by boost, this meant that the 250 Nm peak at 4000 rpm changed to a starting point for the climb to max torque of almost 350 Nm at just over 4500 rpm. Max power 277 whp at 5900 rpm.

We had some issues, a misfire at 4700 and then trigger loss after 6000 rpm. I do think all those things will be affected by the swapover to MaxxEcu and other hardware so we made no efforts to look into this more. We had gotten the results I was after - earlier spool and a baseline of what this turbo will do at a certain boost pressure.

I would really like to be able to test drive the car also but the snow persists so I'm not very hopeful. 

The hardware for the changes have just been ordered. But of course the theoretical dicussions remain. My professor would like me to try a standard Sierra EFI manifold to see if the longer runners could further boost midrange. I find the idea interesting and will try to build the new management wiring loom so I can do that. The supplier of the hardware is my "old" dyno guy and the one I really trust to fine tune the engine. He feels that we are lacking power overall so we have some things to look at. Ideally he wants to have my head (not my head, the Pinto head) gas flowed. We'll see if we can make time for that. It would be interesting although I fear it will mean I have to tear down the head completely to do more porting!

Gustaf

So happy to see this thing almost back on the road.  Beautiful work here sir.

I have been doing lots of thinking and research, and I still am, sort of... But some time ago I made the decision to get the head flowed. "To measure is to know", you know...

While it will cost me a head gasket and and an intake gasket, it also means I get a chance to tidy up some wiring with more room to spare. And now is the time to do that.

The head got taken off the other day. No issues there and I spent some time fabricating a valve depressing tool (tm) for the flow bench test.

I made it so it slips under the ball joint and then you can wind down the M6 screw to open the valve. Using an M6x1 means each turn is 1 mm more opening on the valve and in theory we can flow all the way to 14 mm or so. The cam gives around 12,5 mm valve lift maximum so it should work fine.

It turns out ripping the head off was good anyway. I had a slight suspicion that the valve seals were not doing their sealing job as they should, especially in one or two cylinders that seemed "oily". Certainly, several of the seals were not seated anymore. These are some special low profile Kent Cams seals and they lack the metal retainer part that normal Pinto vlave seals have. The standard Victor Reinz seals are rumored to work with high lift cams so I will double check that. I think I have loads of them.

But another issue I found is more pressing.

The valve collets (cotters?) in cylinder 2 intake valve are smashed and mushroomed. As far as I can tell, this can only happen when the lifter rocks from side to side and when the valve is on the short side. I have seen Pintos where the rocker hits the retainer itself, and needs to be ground a bit, but this is a new one to me. 

I have had a slight clatter that I just thought was valve clearances loosening up but I think I caught this just in time. I have checked all the other valves and none show any signs of touching, but they also had correct clearances. I think I will relieve the lifters a tiny bit to reduce the risk of this happening again, and swap out the damaged parts - if I just can get them before the UK Brexits themselves out of the online shopping world...

Gustaf

Back from the flow bench...

We started by flowing the exhaust port.

Not that impressive...but not much work has really been done there.

Next step was the intake port, with no inlet manifold fitted.

That doesn't seem too bad, to me, compared to other figures I have seen. No record breaking flow but decent?

Then we tried with the manifold attached.

A little bit lower but it seems that the manifold and plenum flows pretty much OK.

Our conclusion was that the exhaust is what is holding the engine back. I was given the chance to borrow some porting tools (the flow bench is at a friends workshop, a 5 hour drive away) to try improving the exhaust port and make a new test the morning after. I worked the port basically as Vizard describes widening it so the turn is less sharp. His measurement is 27,05 mm wide, and I used a template to get to that width or a little bit under. I also worked to get more room around the valve guide.

We only had time to do a quick check at 12 mm lift, and then we had 132 CFM, so that's a decent improvement I think.

Now I have to get all exhaust ports the same and then we'll see if I try to get back on the bench.

BTW, the depression figures differ but I am told the bench compensates for that.
 

After getting home I couldn't stop thinking about that it would be really nice to be able to perform some kind of flow testing at home. The thoughts of a shop vac based bench had been around for ages but now I decided to try. I was thinking that I have a baseline to work from, even though I might not be able to measure true flow I could at least try to make sure I have the same pressure drop.

So I found a piece of plastic tubing close enough to the cylinder bore, fitted that to a piece of board, and cobbled together a connection to the blue Nilfisk shop vac. Some clear plastic tubing was converted into a tube tube manometer filled with food dye coloured water.  I used the leak down tester spark plug fitting to connect to the combustion chamber, and did a trial run. The manometer indicated something like a 8-10 cm height difference, so I printed a simple scale and hey presto!

The real test was to see if I could spot a difference between the ported exhaust port and the other. And I did! Cylinder 2 had something like a 10-20 mm higher  pressure (left my notes in the garage). While it would have been nice to get more flow for a better resolution, I think it should work. I tested at lifts from 6 to 12 mm and the pressure changes with each lift setting, enough to be measurable. 

The idea is to give me a tool to make each runner flow basically the same. Absolute readings are a bit sketchy but in theory I should be able to see if I make improvements to all the ports. This is fun!

Gustaf
 

This is another one of the projects I love seeing on Page 1. Nice valve opening tool, good choice of 1.0 thread pitch! :-)

Yeah, the tool needs developing though as it will flex when pushing against the valve springs. On the bench we used a clamp to control it. Yesterday I tried some more permanent ways but I need edition 3.0 or something for it to really work.

But I also need to find some soft springs to use - the inner springs I have from a double spring set go coil bound before I get max lift.

Last night I started thing that I could have skipped the U manometer and probably rigged one of my old Megasquirts instead. The MAP-sensor should be sensitive enough and if I would have connected the TPS to the valve tool I could have made a log with pressure vs valve opening. That would be cool...and...it would be possible to connect a MAF to actually measure flow. Darned, I might need to look into that...

Gustaf

Yeah, I actually could refrain myself from overbuilding the flow meter.

Instead I adjusted all exhaust ports to be reasonably close. The intake ports were harder to measure since the shop vac pulls more vacuum and the measurements started fluctuating. My valve spring tool compressor adjuster became more and more floppy too, and I had no soft springs that would allow full lift. With no springs, as expected, the valves just fall down or get sucked down. But I did some small things at lower lifts at least.

There is a plan on the engine itself but it is a little bit on hold. Covid restricts travel to my friendly machinist and I also wanted to lay out the MaxxEcu harness with a block still in the car.

In parallell during the fall I have been working on a dedicated wiring schematic. I like the tool SchemeIt that DigiKey provides. It's easy to use and works pretty nice.

I have tried to somewhat place things where they are in the car but it's not 100% correct. The important thing is really what's behind the firewall, and not. I still need to adapt to reality (added connectors to make the CAN and E-pedal pigtails removable) a bit.

With this as a base, I could order connectors, braiding and the other stuff needed. I have chosen expandable nylon braid for most of the harness. It is easy to work with and looks reasonably neat, and adjustments can be made if necessary. Of course it will not protect against dust or moisture but the way this car is used I don't think it will be an issue.

I have also tried to take care to mark and label the connectors. The MaxxEcu wiring harness is a very good start, most (if ot all?) wires are printed every couple of centimeters but I like to state my use clearly.

I use laser printed labels from my desktop, and clear shink wrap. It looks decent, it's cheap and I can decide what labels I want...

I'm waiting for the correct connector to the accelerator pedal, and then it is sort of done.

I dare not really show the under dash, yet...I have used many hours to label, tidy and adjust the wiring that has been done gradually over more than 20 years. Let's say it's not all to the same standard, and I have had think hard about how I actually did some things. Wiring should not rely on the memory... :-)

Gustaf