1993 Infiniti G20 Cheap Endurance Race Car

I think we have been lucky with the engine on the P10, it burns no oil, oil still looks fresh after race(s) and we haven't done anything else than oil, filters and spark plugs. We do run a thicker oil though, don't remember the grade now but with standard spec oil we lost pressure when warm at idle.

Nissan 200/240 SX (S13) wheels are what we used first and then we have just found used wheels in ads, usually from Primeras but the first generation Volvo S40/V40 also fit, but may need spacers since the ET is a bit high.

We have been running 7x17's but that's probably not ideal on a rather slow track since our choice of AD08Rs means the tire gets a bit high (205/45-17, would like 205/40-17). We may try going back to 15" for a test day and see if the lower ratio will help.

We'll check the head on the P11 but hope that a skim will be enough.

Gustaf

I'm running 205/40-17 on the street, the handling is sharp but ride quality definitely suffers.  I was thinking of going up to a 205/45-17 or going down to 15's to get some sidewall.  Unfortunately we are pretty limited on how much tire will fit under the fenders with the P10, as least thats what the internets say, i've got a spare wheel that i could mount a bigger tire on to see how wide I can go before it starts to rub, 225 is probably past the limit for me as i've installed 2" lowering springs and I get some light rub with the 205 .  I've been running Shell Rotella T5 10W30 and it's worked out pretty good so far, just have a pesky leak I need to seal up. 

Update!

I'm still alive and so is the project.  Its very difficult to find time to work on the car, much less update the thread. We have a newborn in the house to go along with our other 2 kids, so there's times that I might get 30 minutes/week or no time at all to work.  But this last weekend the nap times seemed to be all synchronized and I put in a good 4-5 hours of work in 3 days.  

New set of piston rings came! Great! Bought another full set just so I could use one of the compression rings! $38 for a set or $28 for one ring.... Seriously. 

Bottom end assembled! Checked all the clearances with plasti-gauge... Basically to make sure nothing massive is wrong.  There isn't much adjusting to do since I don't think I could get different grades of these bearings even if I wanted to.  All the clearances (ring end gap, rod, main) seem to be on the loose end of factory spec, if not slightly outside of spec.  I am not sure how to build a performance engine exactly, I think they're supposed to be loose anyway.  I suppose I'll find out.  I know the right way to build a street engine would be to select all the parts and/or machine the engine to have clearances within OEM specs.  I'm not sure that's really going to matter on this project.  I didn't find any huge problems with clearances so we'll run it and learn something (hopefully not the hard way!).

Head's back from the machine shop.  Came out very good, they only had to remove .004-.005" to clean up the surfaces.  The headgasket is an Ajusa.  Kinda rolled the dice with this one.  They made a good gasket for my old car (Sentra Spec V - QR25de) and I read really good reviews about it from the DSM guys. Its a composite gasket like the OEM and was only $21 ish. Looks good to me. 

Mic'd all 2 sets of my OEM head bolts to find 1 good set within OEM specs.  I was surprised at how many head bolts I found that had lengthened from being torqued.  Usually I check the head bolts on Nissan engines and it's a waste of time because none of them are even close.  Found quite a few that failed this time though, so I'm glad I checked.  Ideally I'd use some ARP studs, if I race with this engine a lot I'll do them next time.

Head on, torqued. Timing chain, oil pump, rockers/lifters/cams put on and torqued. I had a problem with the oil pump/front cover.  It looked significantly taller than the deck of the block. I was pretty pissed when I found this, as it looked like it was about .005" taller.  To me this seems like it could definitely lift the head up enough and make the headgasket weaker around cylinder 1 area.  People have had this problem when they deck their blocks and do not have this cover attached.  I didn't deck this block so I have no idea why this is occurring.  This is the oil pump that came on the block, and this engine did have a blown head gasket.  I decided not to risk it, and pull the cover and try to sand it down.  It doesn't have to be as precise as the block surface so I didn't mind doing it at home, it's supposed to get some RTV anyway and just needs to hold oil (not combustion pressure/coolant pressure).  Kinda doubt a machine shop could have  machined this surface by itself anyway, and I am NOT taking the bottom end back apart and sending it off. 

Of course while all this is happening I'm constantly looking for deals on race car parts I know I'm going to need. So I snagged some Tien springs (the only one's I can find) for $80 shipped!

Some s13 alloys for $100 delivered.

....aaaaand the best part on the entire car.... Birthday present from my wife and kids! 

I've been pretty much obsessed with Sparco wheels since before I could drive.  So it's fitting that the only nice part on the car is the wheel. And if this car doesn't work out in the long run I can always quick-release the wheel off and take it to the next car!

More updates coming soon!

Nice. I may need to pick your brain on working the insides of the SR20DE when we get to that point in our build.

Gustaf

Anytime Gustaf.  I'm not the most experienced SR20 builder.  I've only rebuilt 1.5 of them now. But I've rebuilt a ton of engines, mostly Nissan, and this one's fresh in my mind. Should be able to provide some level of help. 

Things are moving right along. I'm getting like 20 minutes a day to run out to the garage and wrench in between parenting and marital responsibilities.  It's amazing that anything's getting done, and 5-years-ago-technician-me would be losing it by now.  But I'm very grateful to have any time to spend on the car. 

The engine is assembled, so I'm working on bolting on the manifolds, accessories, etc. 

The only problem I ran into here was the upper/lower oil pans.  Apparently they're different between the P10 and the B13 that the other engine came out of.  Unfortunately they have to be used as a set, you can't interchange the lower pans etc.  And I did a great job of not keeping them organized so I wasn't 100% sure which was which.  However, I failed to clean up the P10 upper oil pan because it was so nasty.  So I cleaned that one up, and matched it with the lower pan that fit... Little extra labor but I'm glad I'm putting the pans back that came on the car.  

Engine is off the stand, with clutch, flywheel and trans bolted on!  Can't believe the engine's almost ready to reinstall.  

Very glad that this project is almost running again.  I underestimated how hard it would be to drag this project out for so many months.  I BETTER have done a good job, and not have any problems with the rebuild.  With so little free-time to do this stuff it would be a disaster to have to pull the engine again.  When i was searching for a car, I didn't consider an engine rebuild to be such a big deal.  They've never been a big deal for me in the past, and I wanted the peace of mind knowing that I'd gone through it and replaced worn parts.  In hindsight I probably should have waited for something that was running good, but no turning back now!

In reply to SuperTouring :

You are killing it! Keep going! 

You gave me flashbacks to when my SR20 was in pieces all over my garage.  Please tell me you installed the rear main seal retainer before you bolted the transmission back on..  Great Job!  If you get a leak from the Timing chain tensioner I have the part number for the improved gasket, if you decide to change it be careful, one of the aftermarket ones (Cloyes) doesn't fit the FWD SR too well.   

In reply to 06HHR :

HAH! Yeah I remembered to install that before putting the trans on.  I'll keep that in mind.  I used a FelPro gasket, so we'll see how it works out.  I reeeeeally hope I don't get any oil leaks on this rebuild.  I used a bunch of gaskets that I've never used before, which I don't like to do.  Hope it doesn't come back to bite me. 

Made some more progress last night.

3M Window Weld to fill the motor mounts.  Not 100% sure how this is going to turn out.  I heard mostly good reviews on this method, and the bad reviews were usually related to people not waiting for the stuff to cure correctly.  One thing that I'm not thrilled about is that the durometer rating is close to what stock is.  But for $22 it fits the theme of the project.  I'm not going to spend $300 on a set of motor mounts for this car... ever.

Also removed the AC components in the engine bay, I'm ready to roll the engine out to the car and drop it in.  Can't believe it!

We filled our mounts in a similar way after the first season. Hard to say what kind if difference it made and one of the fillings fell out - I suspect we didn't get the rubber clean enough. But I do think it's a wise thing to do - we blame the gearbox failure during the first season on the old mounts failing.

For the P11 we are also looking at making an extra mount to keep the engine in place.

Gustaf

BIG UPDATE!!!!!!!!

Engine sitting in the bay!!

Just trying to hook everything up.  Unfortunately it was quite a while ago since I took this dang thing apart.  Trying to remember the correct way to route the harness. I haven't had an engine swap take this long since I was 18!

Also deleted the EGR which was a bit more of a project than I expected. 2 block off plates, 2 plugs for the exhaust and a whole lot of vacuum lines rearranged. 

Major SCORE!

Set of BFG Rivals (Non-S) in 205-50-15 for $100.  Came off of a miata that's now full-time spec miata.  Guy did a track day on them and no longer needs street tires. 

More to come shortly!

!!!!!!!!!!!!

Well the thing runs.  As seen in the video above, gracefully filmed by my crew chief (4 year old). 

Cranked the car until the oil light went out, then connected the injectors and it fired the first try.  There was a misfire that I was able to take a look at a few days later.  Confirmed spark,  and 160psi of compression.  Guess the fuel injector went bad from just sitting there (great!!). So I got to work swapping one out from the spare long block I bought (boy that thing is really coming in handy).  

In fact it was the cleanest, fastest side feed injector swap I've ever done.  They're 30 years old and usually come apart, or have a little bit of damage after removal.  The only part that's exposed is all plastic, and the two o-rings in the seat are usually frozen in the rail.  For some reason this swap went really easy and fixed the misfire. 

Took the car out for a drive.  I had about a minute of run time before taking the car onto the road, mostly up to temp.  My boss (spec miata/vintage racer) recommended his break-in procedure to me.  Basically run it and make sure the oil pressure is good and the engine is running smooth.  As it's just reaching operating temp wind that bad boy out.  So I went about 90% throttle up to 7000 rpm and then let the engine drag. Did this a few times and then went through 2nd and 3rd gear WOT a little ways up the rev range.  Other than a lot of smoke from oils and fingerprints burning off of the manifold, the new engine appears to PULL! I was a little surprised at the power it had, was expecting much less. 

Pulled the car back in to build a 2.5" exhaust using a 350z midpipe as a donor.  At the same time I'd like to put my lowering springs on and assess the suspension situation.  Things I'm going to be looking into:

-Modifying my upper strut mounts to gain back some lost shock travel

-Cutting front upper control arms to gain camber

-Checking condition of stock struts

Here's how the car sits, rear lowering springs on.  Front is at stock height. 

edit: OH yeah! BFG Rivals installed!

Nice work, and good test run.

I'm not sure on how to run in our rebuilt engine, the car is not really road legal anymore. Technically speaking it is still registered though and if we put the license plates back on and run it before we add start numbers and stripes it's pretty stealth. Might work...

Gustaf

Thanks Gustaf. I'm going to aim to keep this car street legal. Driving on the road, if for no other reason than testing will be valuable. Also, at least while I'm making it into a race car I might choose to drive the car to a track day/autox. 

I have a question for you about your front suspension. There's talk of the front shocks running out of travel when lowering the car. Apparently you're supposed to use strut mounts that raise the mounting point back to OEM height so that the damper doesn't bottom out. Do you have any experience with this, or have an opinion? 

Thanks

Road legal is nice :-)

I have not seen any issues with bottoming out on our P10 but to be honest I have not really checked systematically either. It "only" has a 35 or 40 mm lowering kit so it's not very low. But I have also read about the issue and I think we will check the travel on the new car.

I do suspect we hit the bump stops now and then though. But that's also partly what they are designed to do. Come to think of it...some drivers have complained about a pushy feel, may well be because of that.

Gustaf

Okay.  I was hoping to avoid chopping up/re-weldling the strut mounts but I better just go ahead and do it.   

Unfortunately on this build I don't have a lot of time to test and see if certain suspension mods work.  I have to rely on other people's experiences with this car and make a decision on if that should be done to my car or not.  Seems like the community as a whole supports these 3 modifications to the suspension:

-Raised upper strut mounts

-Shortened upper control arms

-Lower mounting point of upper control arms

Think I'm just going to go ahead and do these 3 things before putting the suspension back together.  Get it all done at once and not have to re-do it later. 

Thanks Gustaf

Suspension UPDATE!!!

As I stated in the previous post.  I relied on research and testing from the G20/Primera community and made some modifications to the suspension while installing some lowering springs.  

Relocated upper control arm mount:

Upon Gustaf's recommendation, I checked out the dynamic camber graphs done by CovertRussian on the G20.net forums. His research was pretty convincing.  Relocating the upper control arm mount 15mm down and 5mm in improves the dynamic camber graph considerably.  The change in camber is dang near a straight line as the suspension compresses/decompresses.  Both people reported a better driving feel as well. 

Raised upper shock mount:

Cut the bottom off the mount

Took the bottom and plopped it right back on the top

Welded

Painted

I really need to convert my flux core welder to MIG so that I can cut down on the splatter.  That said, it was pretty fun to make these.  Saved $100 on aftermarket ones.  Gained about 3/4" of shock travel back.  I was glad to find a pretty simple way to modify the stock mounts. 

I didn't shorten the upper control arms.  I probably will in the future, but I need to check my static camber after relocating the upper control arm mount and lowering the car.  It might also be a good idea to see how the tires wear after a track outing and see if/how much more camber is going to be needed.  I'll have the suspension apart again almost certainly to replace these stock struts soon. 

 After driving the car into the garage on it's lowered suspension, race tires, half built exhaust, and actually running engine combined with this weekend being the first local track day of the season.... This is starting to get pretty real! If I'm going to make my goal of doing a track day in this car this season then I need to really focus on things that need to be done to make that goal.  I'm going to try not to get distracted with a billion other tasks that need to get done on the car, and focus on things that have to get done before I track the car.

-Finish Exhaust

-Repair a few bolts (crossmember, brake caliper) and harness connectors (alternator), replace front ball joints (super loose).

-Fresh gear oil, brake fluid

-Upgraded brake pads of some kind

-Remove Airbags (stretch goal of installing my sparco wheel)

Hey, just read through this build, it’s great!

Really in the spirit of GRM and I like your attention to detail, deal making and cost saving methods. 

Can’t wait to read the next installment. 

Again, Well done.

In reply to Chappers :

Thanks Chappers! I really appreciate the compliment.  Sometimes its hard to see my extreme cheapness as a blessing, but it certainly is in some situations.  It helps me to keep living my passion for racing cars even with very little time and money to invest.  I get a lot of funny looks from some of my other car friends.  The looks are like "....why do you do the things you do?"  But I'd gladly take this over putting my car hobby on the shelf until the kids are grown and gone. 

Sounds like I'm in good company at GRM. 

More on the last update, forgot the picture of the final product!

Awesome job going for it and pushing through some of the low spots!  Cars looking great so far.  I loved the old Primeras in that era of the BTCC, particularly the Vodafone/factory team.  Those cars started my passion for all things touring car later in life.

I've always heard the G20 was a unique offering so it's neat to see you find out the potential this thing will have on the track!

Man im so glad this thing is coming along so nicely. I cant wait to see it on the track. Your G20 may beat my G20 to its first laps!

In reply to ScottyB :

Thanks Scotty.  BTCC was sure exciting stuff.  I admit I'm not an OG fan by any means. But the Calsonic R32 GT-R has been one of my favorite cars since I was in high school.  When picking a cheap but good car for low budget endurance racing, the G20/Primera seemed to be a pretty complete package.  The fact that it raced with the same livery as one of my all time favorites made it an easy choice. 

In reply to B13Birk :

I'm glad to see it coming along too.  Didn't think it would have been this big of a project to get this far, but I'm glad I did it.  I hope to get on the track soon.  My car might get there first but it's just because I'm trying to hit the track with the least possible amount of changes from stock.  I really only want to change things that I know are insufficient or unreliable for track use.  After I get some experience and some data I'll make changes if it fits within the class/series I will run with. 

Oh, the upper mount solution looks nice!

I have some hopes of a wrenching feast tonight, will have to look into doing that on our car. Didn't realize it was so easy. 

We shortened the upper arms before relocating the mounting holes, but the combination is what really put our tire wear in the reasonably right spot.

Gustaf