I'm mostly writing about this b/c I'm pretty excited. You know how long it's been since I ordered parts from Summit to actually DO something with my/a car??? Way, WAY too long. Over 20 years. I did the Kart project, but that didn't require much for parts, and those that it did, I made or modified to work.





Anyway, The Kart's dead-dog L98 is coming out, and the ZF6 (toughest transmission ever put in a car!) is coming out with it. The L98 does deserve a moment of respect; it DID do 289 RWHP, with an intake and exhaust. Anyway, replacing those parts are a sbc 400 w/cam, light porting to the L98/113 heads, American Racing headers, HSR....and requisite tuning...in one form or another.

The ZF6 will be replaced with a T5. You know how long it's been since I messed with an F-bod T5?? Probably close to 25 years! I'm looking forward to picking it up with my bare hands, lifting it up into the trans tunnel, and sliding it into the bell housing. Ahh....Haven't done that in a while. A loooong while. Tonight I ordered the required items to slap it all together:
'Vette pan, with LH dipstick and 2 pc RMS
Flywheel
Clutch kit
OEM Roller timing chain, thrust plate and cam button
balance plate for the 400
6.1" damper for the 400-in-a-C4
Short throw billet shifter w/adjustable stops. Mmmmm it's been a LONG time since I rowed one of those in a T5.
Gaskets to put the engine together....that's about it. Stuff should be here next weekend, can't wait to start throwing it into the car....can't wait even more to drive it. Funny thing is, I think I'm more excited to shift that shifter than anything else!

 

hmm i think i would have left the engine and added a turbo to it.
probbaly cheaper, and way more fun than a 400

 

Copy that. I don't agree, but to each their own. Also, the engine was poorly maintained before I got it, and not long for this world. Then, it died and left this world. Likely would have done so quicker w/boost on it.

 

So the proper answer here is build the 400 and add the turbo!

seriously though, what does the cart weigh? Like 2k lbs? It's got to be sooo fun!

why swap the ZF trans w t5? Not disagreeing, just curious.

 

You read my mind. ...and the turbos are already sitting in "the museum". All the tq of a 400....and THEN the boost hits! Also, it will have a longer/better rev range than a boosted L98.


Good question. Kart weighs 2250 right now, w/no gas. That is more than I'd hoped it would turn out to weigh, and surprising after all the **** I took off of it. I'd like it to weigh less, and the T5 will remove ABOUT 100 lbs from the car:
ZF6=145 lbs
DM FW=35 lbs

T5=75 lbs
El-cheapo FW= 16 lbs.

Clutches are probably similar weight. 145+35=180lbs for the ZF and 75+16= 91 lbs for the T5. So, I'd lose about 89 lbs with the switch.

WRT Durability, with the Kart, I don't feel that I need it and I'd rather save the miles/wear on the ZF6 as a back up for my regular 'Vette....or sell it to someone who needs it. But the Kart has no traction and the tires'll spin (and spin and spin and spin) long before the T5 "feels" the hit. I think the T5 will survive fine, shift awesome, and save a bunch of weight in the car.

 

Yeah, I'm sure the t5 will be fine, I think they get a bad rap. That's gonna be a blast to drive.

 

Yep. hopefully. "An amusement park ride, that you control."

I really thought the thing would come in around 1800-1900 lbs....there is so little left, to the car. After the trans swap, IDK how to get the weight any lower, w/o swapping to a lighter engine, and the options aren't obvious, or good. Aluminum LS's aren't a lot lighter. Somewhat, but not 200 lbs lighter....not even 100 lbs less. And same goes for any other V8 with some power; Northstars, Infiniti FX50, Lexus, BMW, Jag, ....they all weigh 450+, so no meaningful savings. I've thought about the "Buick 215" V8, in Range Rover form at 5.0L, but those thing don't make power and are totally unreliable. SoI kind of end up back at a SBC, and why not use the biggest one you can get in that package/weight? That's a 400.

Otherwise, I don't see where meaningful weight could come out of the car.

 

You are talking ~100 lbs for a ton of money and that is starting with iron heads. The all aluminum Dart 400 was 366 lbs in this article. All cast iron was 476. Just taking a wild guess it would be easy to lose 60 lbs on your rotating mass. Those tires and stock Vette wheels are fairly heavy. The more weight you can shed that is either rotating or unsprung the better the Kart will perform.

https://www.motortrend.com/how-to/en...k-engine-build

 

I don't quite follow what you're saying there; are you seeing low hanging fruit that I am not?

Those are C5 Z06 wheels; they're pretty light, for the money. I could buy carbon wheels...but that would be
-and not even close to 100 lbs. What I was saying above, is that when you look at all the OEM (affordable) V8 engine options, there really aren't any that are markedly lighter than the SBC, and many have other significant drawbacks. I was simply saying that I thought the Kart would end up ~1900 lbs and it didn't. I chopped off more than most kart builders, so I don't see a lot of low hanging fruit to make a meaningful diff. Also, does it need to be lighter? Not really. I'm at...WAS at 7.5 lb/hp right now, with that beater/turd L98. . I even thought about trading the D44 rear for a D36...but the weight diff is only a few pounds....not worth it.

 

What I was saying if you went with an aluminum block small block or aluminum LS it would only be ~100 lbs lighter than an all cast iron SBC. So I was agreeing with you. With the 400 you could go to an electric water pump and a bracket that only has the alternator and run a manual steering rack. Save some power and a touch of weight. Also eliminate the potential of P/S leaks.

I was just throwing something that would make a bigger difference than the static weight reduction alone. The Z06 wheels are ~19 and 21 lbs each. 15 x 8 drag lite is a touch over 11 lbs. 15x 10 drag lite is 14 lbs. Different brands of tires can be as much as 10+ lbs difference. That is where I was getting as much as a 60 lbs difference from, 15 lbs per wheel/tire. I had a full size Ram I ran P305/50R20s on the stock Ram 20s on. Switched it out to stock Ram 17s and 29" tall drag radials in the rear and P245 street tires up front. Knocked 4+ tenths off the 1/8 mile in a 5,500 lbs truck that was already running 8.70s in the 1/8. Truck felt entirely different to drive as well without 84 lbs per corner of rotating unsprung mass.

 

O.K. I got you now. Yep...the aluminum block is engine-guy candy....but definitely not worth it, in this type project. Totally. The T5 swap is ~ 100 lbs, won't make a huge diff in performance, but, it's actually a budget credit to the project if I were to sell teh ZF, DM flywheel and clutch. So, that one is worth it. But yeah, that $11k 400 in the article that you shared....that's for "other people".

I agree with you about the wheels and tires too. Smaller wheels would weigh less too....I don't need 17's and 18's....but I like the way they look and I like that I can swap 'em with the '92 for various reasons and convenience.

 

Welp....I learned that pulling the engine w/the trans attached isn't the best way, on a C4. I won't do it that way, again. I'd seen it written about numerous times, but dropping the trans first would have been a better way to do it.

 

It's kind of convenient, you don't have to take the hood off!

 

That second photo underscores your point about the trans swap. It's easy to forget how large those truck-based boxes are until you start wrangling one around.

 

Totally! That was my exact thought once it was out and I was looking at the thing....I was thinking, "My god, that trans is a BIG chunk!"

I'll put the T5 next to it and take a pic.

 

• verything about it is lighter.
• Everything about it is simpler to get serviced.
• There *is* an aftermarket flywheel for new engine and trans. Not for the 400 / DM S6-40.
• 1-4th GM V8 T5 ratios are totally tractable and match the SBC very well.
• C4 probably had a 3.45? rear and either T5 5th gear is a good match.
• S6-40 ratios have the same pros and cons as the 94-02 T56. Too mich 6th and for applications without a lot of rear gear, too close 1-4. Maybe not for a lightweight like this, but they really only shine in like a roadcourse

Tom is mildly admitting his pride and joy trans. is not ideal for as many applications as it could have been. Hence. C4 only in N. America.

 

Not sure what that means exactly? But you're right on w/the reasons for switching, as it relates to the Kart....except for the gear ratio stuff. Both the T5 and the ZF have good and similar ratios, 1-4. I don't believe that any '89 had a 3.45. This car has a 3.31 rear....too tall, IMO, even for the Kart.


As promised.....Arnold vs. Pee-Wee....Beef cake vs. Pin-pin....

 

Finally had a minute so tore the 350 down, got the heads to the machine shop for 400 steam holes and a chop, if necessary. 400 is ready for the heads.

For S&G's. dropped the pan to see what all the knocking and fuss was about....looks like lack of oil, to me. Which is weird b/c the thing had plenty of oil, fresh oil, and great oil pressure.






Ring ridge was pretty slight for the mileage and poor maintenance the PO had provided for it.


....but the cross hatch is long gone, which is pretty bad for ~160k.

When I dropped the heads off, I set 'em on the counter next to some late "LT" heads....my god, look at the difference in the size of the intake ports!! GEEZUM, BUB!....





Another kind of funny thing, when I pulled the intake off the Kart engine....virtually no oil on the underside of the thing. Haven't seen that before....

 

Thank You very much for those transmission pics Tom, , , , , I never woulda guessed the Vette transmission was SO much bigger than our petite lil T5

 

I can say putting the ZF in my 92 f-body required some serious massaging to the floor pan in places.
Definitely a weird failure, oil filter issue? Rodbolt stretch type failure?

 

You're welcome. I'd never seen one in person, out of the car, so I was pretty surprised also, once I had the thing out. Also surprised me when I removed it from the bell housing and set it on the floor...frickin' HEAVY!


IDK....the rod nuts were tight when I removed them. The engine was pretty full of sludge...I wonder if a chunk of sludge plugged the crank passage?....but since it was cyl 8, you'd think that would have starved both 7& 8? I'm not sure.

 

I am skeptical on the T5 surviving. Personal experience with a 406 and originally a T5 before the TKO...the T5 didn't last long and that was with one trip to the strip with street tires. It didn't fail at the strip, but within a couple years it had started showing increasing amounts of distress. That being said...I am starting to question the condition of the TKO currently as well. It was bought used back in 2016.

Regardless, glad to see the cart getting a makeover. It will be a blast no matter what with that 400 and a HSR combo.

 

We'll see. I should probably state or clarify....because many "bad" decisions are going to be made throughout this build...that this is basically a "no dollar" build. All junk stuff, so the expectations are LOW, if something breaks, I won't be crushed or even care that much. Also, the usage is LOW....that that'll help longevity.

Speaking bad decisions....I am doing an OEM roller conversion with this junk. Is there any benefit to one cam retaining device over another? A button vs. drilling and tapping for a retaining plate?

 

I have a roller button in my 400 inch engine. Been in there 20yrs and 2 cam swaps, so far so good

 

I totally get the "no dollar" build aspect. Might as well use it then in that case. That is what I did when I first had the T5.

For the cam, on my 400 I went with some timing cover that had an adjustable cam button setup on it. Was a bit pricey but made it pretty straight forward and little guess work, which was what I wanted.

 

Right on. Thanks for the feedback, guys.

 

I turns out, I was reminded today....that there IS a benefit of one over the other. The benefit appears to be with the retainer, b/c I can't find a button that's made for an OEM roller. All buttons that I can find are for retro fit roller and thus has the larger cam gear bolt pattern and center hole.

 

Putting the 400 together when I have a minute here and there,




.....and ran into some BFS....

BFS

 

That doesn't look very good