Project Poncho: Daily Driven Muscle Car

In reply to Shavarsh :

My trusty '86 Trans Am is shockingly practical...i once fit a 4x8 sheet of MDF back there.

Got the engine unloaded and on the stand at undisclosed location #2. I'm planning on cleaning it, doing new gaskets, and maybe painting the block black before I shove it in the car. Progress!

how is the final bit of metal work coming along?  Or are you still working up the courage for it? 

In reply to golfduke :

i've been doing metal in the background while i've been doing all of this other stuff. I discovered more rust than i thought there was in the passenger footwell (seems like that happens all the time) so i have that patched. The rear window area is still needing to be dealt with. I decided to get some things ready so I can have fun things to do when I need a break from metalwork.

I think I have a solution about figured out for the transmission scenario.  I'll lay it out for consideration and review below, as well as include information that was somewhat difficult to find. My goal was to minimize the amount of custom parts (not neccessarily custom for the application, but things that have to be custom fabricated for me). I know there will be an adapter plate from the Ford bellhousing to the LS block, but as that will be custom produced the thickness can be whatever I need it to be. I also attempted to use OEM-style replacement parts whenever possible to minimize cost, and at my power level they should be adequate.

An OEM LS1 flywheel (from a 1998-2002 Camaro, for instance) has a deck height of .815" (this is the distance from the crankshaft mounting surface to the pressure plate mounting surface) and was originally designed for an 11.5-12" clutch disk. this will bolt directly to my 5.3 and allow usage of the factory starter.

There is an OEM replacement flywheel available that is an extra .400 thick (Sachs NFW1055 is one example). I believe this was used in some of the trucks circa 2005 to allow use with SBC style transmissions (the crankshaft is .400 closer to the block on an LS than an SBC). RAM and possible others also offer flywheel configurations that are this extra .400 thickness.

My T-45 transmission uses an input shaft that is 10 spline, 1.0625" diameter. To my knowledge, GM never offered this size. they used a 10 spline, 1.125" diameter input shaft on various applications, but that won't fit right. There are numerous Ford applications that use a 10 spline clutch disk, including the late 90s mustangs that originally used the T-45. My plan is to use an 11" version of this disk, which should work with the LS1 style pressure plate.

Centerforce offers an LS1 pressure plate (stock style) that has an installed diapraghm height of 2.050" past the flywheel. I'm assuming this will be identical for any LS1 stock style pressure plate, and these should bolt directly to the flywheel i've chosen. With an adapter plate that's .375" thick, this will give me enough clearance behind the pressure plate to use a generic chevy style hydraulic throwout bearing that are cheap and easily available.

I will need to use a custom pilot bushing that extends approximately .5" past the end of the crankshaft to allow for proper input shaft engagement. I imagine this will be cheap to have made from an oil-impregnated brass or some such material.

So total cost will be: $300 trans, $100 flywheel, $70 clutch disk, $90 pressure plate, $100 throwout bearing, ~$100 pilot bushing, and whatever the adapter plate costs. Still much cheaper than an AR-5 swap, stronger than a T-5 swap, and gobs cheaper than a T-56 or TR-6060 swap.

Thoughts?

Without checking your math it sounds like a great plan! Having never built an adapter plate before; is 3/8" considered thick enough?

In reply to Shavarsh :

3/8" will be strong enough but doesn't allow much thread engagement. Whether steel or aluminum, I'd want 1/2" thread engagement for bellhousing bolts threading into the plate.

If i move to 1/2 adapter plate, the TOB still fits good, but i lose a little bit of engagement between the clutch disk and the input shaft. Based on my CAD, i would have approximately 72% engagement while the clutch is engaged...i wonder if that would be enough

In reply to budget_bandit :

Is there any place where a bell housing bolt protruding through on the engine side of the adapter plate would foul with the engine block or any other part? Because if not, you could add material to the engine side of the plate in the bell housing bolt locations to give additional thread engagement without changing the functional thickness of 3/8" plate.

In reply to AngryCorvair (Forum Supporter) :

unfortunately not. the patterns are pretty close together, i actually had to rotate them 1deg apart to avoid the dowel pin holes overlapping. I think for the time being, i'm gonna run it without full engagement on the splines.

if it becomes an issue, i suppose i could always get a custom clutch disk made with a thicker hub to get more spline engagement down the road

It sounds like you are on a good path with the t45 swap.  If that doesn't work or you want to simplify things an s10 NV3500 should bolt right up and they came stock in GM trucks with the 4.8 and 5.3. I believe all you have to do is get the correct flywheel to convert to the more SBC style bolt pattern.  

In reply to staffma :

i'm not gonna do that, the gear ratios in the NV transmissions are pretty awful for a sporty car. something like a 5.5:1 1st, 3.5:1 2nd and 1.75:1 3rd. First would be almost unusable, and the 2-3 shift would be like going 1-3 in a normal trans. I'm reasonably confident in this T-45 now, and if that doesn't work i'll probably look for a dodge application TR-6060 because they seem to be cheaper

In reply to budget_bandit :

The gear ratios you are describing are for the full sized truck transmission- that's why i specified S10 NV3500. S10 gear ratios are 3.49:1 , 2.16 :2, 1.40:3, 1.0:4 0.73:5.  I have this exact trans in my 70 Skylark and it gear ratios work out well and it shifts well with a hurst shift tower on it. 

  The overdrive on 5th could be deeper  -that's the reason i went with 3.42s when i re geared instead of 3.73, but other than that its pretty good. 

The dodge option does pique my curiosity, having another gear would be nice. 

In reply to staffma :

I've read that the dodge 6060s have a longer input shaft than the GM versions, which should alleviate any concerns about having room for an adapter plate

The steering column that came in the car is fixed/no tilt, column shift, had no ignition cylinder, no turn signal lever/switch, and has notchy bearings.

This morning I bought a tilt, floor shift column for $50 from a late 70s F-body. This one has good bearings, a turn signal lever, and comes with an ignition switch. Buying an ignition switch and new bearings would have been $75-$100, so i saved $50 and got tilt and got rid of an empty column shift hole

I've been travelling (both for work and personal stuff) for the last 2 weeks so nothing's been done. and i'm leaving again next week, so im trying to thrash at the moment. I've wire-wheeled underneath the front half of the car, in preparation for undercoating. After that is complete, i'll reinstall the front suspension and undercoat the rear half.

In reply to budget_bandit :

As Faith No More once said, oh it's a dirty job but someone's gotta do it.

nice work on getting the underbody cleaned up. Are you painting the bare areas before undercoat? Is your chosen undercoat intended for bare metal?

In reply to AngryCorvair (Forum Supporter) :

Thanks! I hope it'll be worth it after i start driving the car, i imagined that having the underside nice and clean/coated every time i work on the car would be worth the labor up front.

I'm using Chassis Saver paint, which is designed to adhere to anything except super loose scale rust or pristine super smooth bare metal. I might be wrong calling it an "undercoating", they market it as a paint i think, but it goes on real thick and cures up almost like a really hard rubber. I really like the finish

Well, I started painting tonight but it's way too humid. This stuff is moisture cure, so 90F/90%+ humidity Tennessee summer yields a remarkably short pot life. 
 

Unfortunately, it's going to rain foe the next few days. It may not be favorable conditions before I have to leave town again, which would be a huge bummer.

Got lucky weather this morning, and got paint on the front half of the car. Gosh this stuff is a pain to use upside down...i can't seem to hit the sweet spot between "enough paint to cover" and "not so much that it drips on me". I'm wearing a fair bit of this paint...oh well. You'll see i skipped the trans tunnel, because I expect to have to raise it to clear the transmission.

So then i reinstalled the subframe, and started to put the suspension on. It looks like a car again! I'm suddenly extremely motivated again, just in time for a business trip 😤

Yass!  I am loving this build!

In reply to budget_bandit :

Man, just anticipate the fun you'll have to look fwd too, on the home trip!!!

Sire lookin' good. 

budget_bandit said:

300 trans, $100 flywheel, $70 clutch disk, $90 pressure plate, $100 throwout bearing, ~$100 pilot bushing, and whatever the adapter plate costs. Still much cheaper than an AR-5 swap, stronger than a T-5 swap, and gobs cheaper than a T-56 or TR-6060 swap.

Thoughts?

Have you looked into using a 4 speed muncie or t10? I used a m22 in my 600 whp 5.3 turbo setup. Big benefit is the transmissions are indestructible and parts are very plentiful.  

My setup:

$50 BBC belhousing, will bolt up with only 1 bolt not aligned

$450 Custom flywheel, LSC performance(they do the flywheels for novac adapters), you could use the truck part but i didnt want to risk have a cast flywheel burst. Plus side is they drilled and tapped it to take a sbc,bbc and ls clutch

$30 Bmw clutch slave with some welding to replace what would be the stock zlink. I would recommend just doing a hydraulic throwout bearing. 

In reply to mitch5 :

I never considered that because overdrive is a non-negotiable for me.

Back from traveling and finally had a bit of time to work on the car.

It slipped my mind that i can't just bolt the subframe back in the car, it needs to be aligned, so i spent a while taking corner measuremenrs and whacking the frame with a deadblow. It's now within 1/8" across corners, which is almost certainly as good as when the car left the assy line.

I started to prep the trunk for paint, and when i pulled off the spare tire holder (by cutting off seized bolts) i found some rust under it...shocker. So i cut a patch for it.

And welded it in.

i'm getting faster at that. Those little magnets help a ton, i should have spent that $8 a long time ago