🔧 BUILD Upside-down M90 GTP build thread

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When your wife gives you permission to build a racecar, you build a racecar.

This is what happened to me. However, all funding for this project comes out of my construction account. I really need a telehandler, so this is very budget friendly. Luckily, I've been stockpiling parts for years. This isn't an overnight build by any means. My goal is to make a 1/4 mile pass with it before the tracks close for the season. I'm taking a risk here and using photobucket for image hosting, so hopefully they don't screw me over again.

So let's start it off. I bought a 04 L26 motor with somewhere north of 100k on it and started to tear it down.

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Everything looks good so far. The pistons are really clean. There was some junk sitting in the oil pan, but not much.

Turbocharged400sbc

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yes esp dep on gasket used.

ears bend with the graphite gaskets oem gskets leak if the pockets not the right depth or the ears are bent from a prev install of graphite....or if the raised lip has a tiny dimple from sitting on a shelf in a bag and getting tossed around

weld the vband with its mate clamped to it to hold it true and flat....i have enough spares that i have 2 clamps with one lip ground away for easier weld access with my little mig (sucks when you accidently weld yer flange to your clamp when you sneeze........

once the first flange is welded, install as is, tack other pipe to it, unclampo after marking index lines, reclamp as it would be in car, weld other flange.

now you never need a gasket, though before O2 i use a fingerprint ridge deep skin of copper rtv. ive gfound it kinda "charrs" off all the organics after a few weeks at 700+* and comes apart when you pop the band clamp off and unwedge each of the three segments.

after you look at it you can see if its warped at all from the look of the separated rtv....most times i just leave it as is and put it back together unless there's a thick area

spend the # for stainless flanges as well as the clamp, i love my Quick release vibrants, underneath id think theyd be the bee's knee's with how often im changing transaxles.

just the work of grinding off the preservative chrome coating on the mild steel flanges makes them not worth it except that the chrome keeps the sealing face from rusting
 
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GTPpower

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I was just planning to use copper rtv. Zzp's flanges aren't usually very flat, but that doesn't really bother me. I've never had a problem with rtv. We will see how it fits though. It might take some modding anyways with my brake booster.

Speaking of, I pulled the supercharger belt off and started the car this morning. The PS pump is nice and quiet while turning the steering wheel, but it does whine when I hit the brakes. So, there must be a bit of air in the hydroboost yet.
 
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GTPpower

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I will give that a try. Most of the air is out, bit every once in awhile it will whine.

But I figured out that both of my cooling fan relays are bad. Not sure how that happened. The fans run all the time though with new relays. I remember that from a couple years ago now that I think of it. 12v stays on the 86 relay pin no matter what. If I don't disconnect the battery, they will suck the battery down fast. Any ideas on that one, James?

I did run the transmission through the gears with the car on jack stands. From what I can tell, it has all 4 gears. Definitely 3&4, and one more. It's pretty hard to tell on jack stands because it commands 1st to 4th in about 1 second. But I'm a bit low on trans fluid, so I should get more before I take it for a drive.
 
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GTPpower

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Thanks. Looks like the next street car night is Sept. 11th. I'd like to make that, but run the car a couple times before then. I'd like to hit up a couple of the 1/8 mile tracks that are a bit closer to me as well.

Me and my buddy Paul were thinking about coming there for Rocky mountain race week in June, just to watch, since we both want to do that.
 
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Rdrnnr

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I'll definitely be around for the funny cars even if I'm just runnin around with the kids for a while. Just wish they were the big nasty nitro cars I miss standing behind but they're still pretty cool.

Idk on the diesel show I don't have alot of patience for some of that jazz but now that I'm almost together I'm gonna try and hit all the test and tune and in between spots I can. Least til the dyne gets here anyway
 
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Turbocharged400sbc

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The radiator fan relays are controlled via ground from the PCM the relays always have positive 12 volt hearts on the primary side. The fuel pump relay Etc are positive 12 volt control.

I've had more than a few issues through the years of the wiring harness causing fan issues via the two and three relay fan systems because of the tendency of the harness above the radiator to get rub through during repair work etc.

Fan control are pins 5 and 6 dark blue and dark green on the pcm c1 connector which is the light blue plastic connector nose.

Check for shorts to ground
 

GTPpower

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Well got it on. I had to massage the upper downpipe a bit due to my hydroboost, and I think they gave me the wrong clamp for the vband, because it won't hold the flanges together.

Started it once, and it sounds pretty good. Sounds like a turbo car, just without turbo noises. I put the blower belt back on and was going to take a video, but the car won't start now. Not sure what's going on there.

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