I'm out of my element. Like a Croce album, this would have been my dad's absolute jam.
I am in imminent peril of owning a car with a "1700" Ford Kent Crossflow engine with dual Weber 40 DCOE carbs.
I don't know how to plug my OBD2 reader in to this, and it doesn't have a J1772 port. Haven't had anything with a carb since Friends was on the air.
I'm looking for suggestions for keeping the engine happy and healthy in a street application. It'll see some good weather standard low speed traffic use, possibly with stop and go, and it'll do medium road trips and autocross.
Also, is there a good supplier or source of info? A book I should buy? I have learned that Ford still makes blocks, and it was engine of choice for a race series, so it seems like there should be a decent aftermarket.
Hitting it with a hammer is a legit problem solving technique for a carb.
It's the Formula Ford engine, right? Pegasus Racing is a known supplier for those puppies.
Might be too much carb for dd. Try it and see.
In reply to iceracer :
If not, I'd bet that it will probably need some rejetting to prevent fouling of the plugs and make it more streetable.
iceracer said:
Might be too much carb for dd. Try it and see.
Based on comments in another thread, this isn't really a DD kinda car. I think "fast road streetable" is more likely to be appropriate.
Honestly they are pretty hard to kill.
Dad had one in his Capri and we had lots of fun with it. He never did anything more to it than routine maintenance (adjust the valves, adjust/clean the points, clean the contacts o the electric fuel pump in the trunk). He had more trouble with the gearbox than he did with the engine.
Keep the valves adjusted and drive it regularly to avoid varnished gas in the carbs and it will just soldier on for quite a long time.
The Formula Ford racers tend to push them harder and much longer than you will and they all want as much power as they can muster, so when we crewed for a friend who raced FF we played with gearing and lapped the valves a bit between the race days.
About points: get a Pertronix if it has points. Just say no to points.
I have a 1979 Ford Fiesta and my winter project is to rebuilt the 1.6L Kent in it. This will be my third Kent Crossflow.
The dual Weber carbs is popular in the UK but to me those carbs are to much until the engine is spinning over 4K, and on the street how often do you do that?
A lot depends on what car the engine is installed in.
A Lotus 7 type car which weighs less than 1500lbs, no problem.
Since my Fiesta is going to be a fast street car I will end up with a single Weber 38 DGAS carb. It has a 34 DATR now which is a fine carb for a stock or mild Kent.
IF you have any questions PM me and I'll try to help. Most of the engine parts you find in the US are Formula Ford parts which means stock 1600 GT cam.
I ordered my pistons, cam kit, and some misc. parts from Burtton's in the UK.
Your 1700 if built right should have a cam with specs over .400" lift at the valves and a 10:1 compression ratio. Power in the 120-140HP range is common for a street 1700, depending on the cam.
Keith Tanner said:
Hitting it with a hammer is a legit problem solving technique for a carb.
It's the Formula Ford engine, right? Pegasus Racing is a known supplier for those puppies.
The proper description is "gentle mechanical persuasion." The amount needed varies, and seems to be inversely proportionate with frustration level.
If money isn't an issue, throw these at it.
Fuel injection
Dang that picture is big. Sorry.
Keith Tanner said:
Hitting it with a hammer is a legit problem solving technique for a carb.
It's the Formula Ford engine, right? Pegasus Racing is a known supplier for those puppies.
Hitting with a hammer is something you have to do to Nikki carburetors after every time you invert them, to reset the floats. If you don't, they will flood out as soon as you turn the fuel pump on.
The other day when I was researching Ecoboost swap packs, I discovered that Ford STILL SELLS KENT BLOCKS. And here we'd been told that Kent Blocks no longer had Ford sponsorship!
I've got a Lotus 7 with a non-crossflow 1600 Kent and dual DCOE 40s. I tune a lot of DCOE-equipped cars at Eclectic Motorworks. Here are my main tips:
- Make sure the engine has good, even compression. Depending on the compression ratio and cam, it should be somewhere between 120 per cylinder and 180 with no more than 10% variation.
- 90% of carb problems are ignition. Ideally, send the distributor to Advanced Distributors or British Vacuum Unit for a rebuild and recurve to the specs for your engine and modern fuel. That's a few hundred bucks, but you'll never regret it. If you don't go that way, make sure you've got it timed to about 15-20 degrees BDTC at idle (vac disconnected if it has a vac advance--Weber cars rarely do) and 32-35 all in at about 3500+ RPM. If it won't time in that range, or the timing is jumping around, the distributor needs a rebuild or recurve or both.
- Make sure you have no vacuum leaks. Spray carb clean around the base of the carbs and manifold while the engine is idling. If the idle changes, there's a vacuum leak.
- I don't think DCOE 40s are too big, but usually find they have venturies (also called chokes) that are too big installed. You can run anywhere from a 24-36mm choke (x4) in those carbs and most people think bigger is better. Bigger gives you a little more HP up high (like 7000RPM) and destroys your idle and low-RPM driveability. Too big, which is common, loses power everywhere. Almost every customer car I've dyno tuned gained area under the curve and driveability when I put smaller venturies in. Once you've got the correct venturies, it's a matter of setting the float heights and getting the jets, air correctors, emulsion tubes, etc. in the carbs. The easiest way to do that is call Pierce Manifolds and ask for the specs and order the parts from them.
- Pat Braden's Weber book is pretty good, as is the Haynes Weber book. They're both 20+ years old, so a little out of date, but have decent explanations and diagrams.
- There are a lot of people that make witchcraft out of Webers or distributors, but they're really pretty simple if you take the time to learn how they work. If you don't want to do that, find a shop with lots of experience and they can dial you in. The people that say you have to change the jets every time the humidity changes are wrong--that's only true if you're a hardcore racer looking for the last 2 mph at the end of the long straight. For the street, once you've got them right, you shouldn't need to mess with them again.
US Fiestas used a Duraspark distributor/ignition that was pretty trouble free. Should be a drop-in replacement for points.
I appreciate all of the replies. I'm bookmarking the thread.
The car is a seven. I'm told that the engine has been tuned to run on 91 octane.
It's sitting in front of a 4 speed transmission. The tach has the red line indicator set to 5500.
Edit: I don't know much about the inside of the engine.
noddaz said:
If money isn't an issue, throw these at it.
Fuel injection
Dang that picture is big. Sorry.
Had some on my 924. The 45's were WAY too big for that motor, but it was one of those eBay buys where they listed it in the wrong category, etc. so I got it for a song.
Aside from being too big, they also had an issue where they wouldn't fully return to idle when warm. Once everything got warm, it would hang a bit in the bores. Not confidence inspiring to say the least.
I have some 40's from Jenvey that I might use, but really a single TB on an intake with a reasonable plenum volume will get you 95% where you need to be with out the hassle of tuning and balance multiple throttle bores.
For his use, a single Weber 2-bbl down draft would be more than sufficient to have fun and be a bit more easy to tune.
DCOEs are wonderful and can be tuned for anything. As Carl said above, most people set them up with venturis that are too large, then complain that there's no power until 4500rpm. Sure, they're a little more work than a single carb, but once they're done they're done. Parts are readily available; I ordered a bunch of stuff from a company in the Czech Republic (I think - they were on ebay) a couple years ago for much less than US prices. The Braden book as plenty of setup info for that engine.
They're worth keeping for the intake noise alone.
Would a downdraft even fit under the bonnet? It looks as though it has sidedrafts as much for packaging as anything else.
I'd prefer to see air filters 2-3 times as tall, more filtered volume before the trumpets, but... packaging.
Pete's air filter comment is 100% on point. There are larger filters with room for internal shorty velocity stacks that will help across the board. The bonnet is probably cut away to clear already too. I service a 1700 Caterham with 40s and it is perfectly tractable as an everyday driver. For several years it was my customer's only car. Does have a 5 speed. So long as the fuel stays clean the only thing that can go wrong is worn out float valves or sunken floats. Simple repair and no tuning change at all.
03Panther said:
Keith Tanner said:
Hitting it with a hammer is a legit problem solving technique for a carb.
It's the Formula Ford engine, right? Pegasus Racing is a known supplier for those puppies.
The proper description is "gentle mechanical persuasion." The amount needed varies, and seems to be inversely proportionate with frustration level.
I prefer "percussive maintenance." It's specc'ed in ounce and pound sizes depending on the stoutness of the part.
I have some experience with the Kent engines in Formula Fords. I can tell you that it's hard to run at the pointy end of the field if the pistons look like this.
That's out of a friends car that I raced at High Plains a few years ago. Even if I tucked the nose right up close to the gearbox of the car in front of me they could just break the draft and pull away on the straights.
In one of those sequences of events that seems weird to normal people but normal to car people I now own that engine and parts of it have made their way into the engine I built for my Formula Ford.
They're incredibly simple engines. We do silly things like run really low oil pressure to get a competitive edge in Formula Fords there's no reason why a properly built less stressed street/autocross engine shouldn't provide miles of trouble free service.
I'm less of a fan of Pertronix than Keith is. I've found their quality control to be abysmal in recent years. I've lost track of the number of cars I've fixed by changing the Pertronix pickup. On one occasion I pulled one in the pits, stuck in a used set of points that someone had kicking around in their toolbox . I've had bad ones straight out of the box and early failures. The OP isn't limited by sanctioning body rules and can run any distributor so I'd look into the 123 unit https://123ignitionusa.com/ford-kent/ I run one with the sanctioning bodies that allow them and points with those that don't.
Pete. (l33t FS) said:
The other day when I was researching Ecoboost swap packs,
Off topic, but that piqued my curiosity. Do tell. Maybe in your Bat Cave thread?
Here's some pics of the parts that are going into my Kent rebuild. These are not FF legal. Big valves, XR2 Intake, and 1.3L pistons, along with a Kent cam kit sporting .420 lift.
RossD
MegaDork
2/5/21 12:18 p.m.
5 speed from a XR4Ti should bolt up in place of the 4 speed. The one question is the input shaft might be a fraction of an inch longer on the 5 speed.
A Zetec will bolt up in lieu of the Kent. Reuse clutch/starter setup of the kent, but will need to cut the "wing" off of the zetecs upper oil pan to use the kents starter location.
On this car, the hood is not cut for the intake, so the filter size is almost certainly a packaging consideration.
Any suggestions for oil weight and service interval?
