1975 Plastic fantastic aka Corvette

[SuperBuickGuy]

Evergreen speedway?

Pacific

[yellomalibu]

Next weekend, Sunday, open track day for the Corvette..... I think I found the issue with the EFI, so it stays until after the track day. However, I need to pull the transmission again and make sure the clutch is happy. While I'm at it, I'll swap oil pans to rid myself of the leak around the drain plug and put a well-baffled pan in its place.

What are the signs of an unhappy clutch? Signs of slipping? Hot spots on the flywheel?

...and I'm guessing "open track day" is for a road course not a drag strip - but still, if you have to change any clutch parts, will you have enough time to break in the new parts before beating on them?

[SuperBuickGuy]

I'm simply going to hit the surfaces with a disk and figure out why that stupid hydraulic throwout is too close....

first a reminder of a potential problem with boosting SBC 400s .... I needed to pull the motor out to steal its pan




why can't it ever be easy? stupid bolt


interesting, there was a 1/4 bolt floating around in the pan. I have no idea where it came from.... ah well


nice and clean... once the glue dries it'll be ready to go up - note the edge scraper, and the much better baffles?



cheap ass Taiwanese pan

[Deaf Bob]

Looks like boosting 400's is a bad idea!
That's rough!
The siamesed bores really do not like heat!

[SuperBuickGuy]

there was a vacuum leak under the intake manifold that precipitated the destruction, but yep - bad day.

[SuperBuickGuy]

decisions, decisions.

I feel like I've pulled this transmission as many times as Randal has changed cams...

problem 1
the pressure plate is riding too close to the inside edge


problem 2
why did they chamfer this hole? how do you get an accurate measurement for the depth? at this point, I think the throwout is 1/4" too close to the pressure plate (about the same dimension as the chamfer


problem 3 it's leaking - which could be the cause total of the problem with slippage


Interestingly, neither Speedway nor McLeod list this bearing for the Super T-10 anymore.... and the one they do list now is $317.00 and will not be shipped until the day after the track day (11/18)

square instead of chamfer



so what to do.... I might be able to switch to manual actuation if I pay huge bucks for next-day air for the parts... it also means I have to pull the entire dash out to replace the pin on the clutch pedal (had to remove it for the hydraulic system, naturally).....

I'm at a loss.... I think I have enough parts here to put the transmission back in the car with the clutch arm, pivot, and non-hydraulic throwout.... presuming the clutch pad isn't toast because of hydraulic fluid....

of perhaps buy a hydraulic slave cylinder that mounts to the outside of the bellhousing. I have a bellhousing would work, but I'd lose the scattershield (not optimal, but a possibility)....

[Scott Liggett]

It's a little hard to blame your 400's demise solely on boost when you said it had an intake leak and a bolt bouncing around the crankcase. But, I will look into it.

[SuperBuickGuy]

It's a little hard to blame your 400's demise solely on boost when you said it had an intake leak and a bolt bouncing around the crankcase. But, I will look into it.

Scott - I'm not a pro, I can only relate what's either happened to me; or what was told to me by someone I should have probably listened to. As I told you before, you mileage may vary.

In any case, I'd be the highest order of jerk if I didn't mention this to you now...

[Scott Liggett]

Scott - I'm not a pro, I can only relate what's either happened to me; or what was told to me by someone I should have probably listened to. As I told you before, you mileage may vary.

In any case, I'd be the highest order of jerk if I didn't mention this to you now...

I didn't go into to this lightly or without thought. I have a studded 350 four bolt in my car now that I could buy forged bottom end parts. With the billet splayed main caps and the short fill, these will hold for what I want power and boost wise. I am not going for 1000 hp and 20 lbs of boost by any means.

[SuperBuickGuy]

I didn't go into to this lightly or without thought. I have a studded 350 four bolt in my car now that I could buy forged bottom end parts. With the billet splayed main caps and the short fill, these will hold for what I want power and boost wise. I am not going for 1000 hp and 20 lbs of boost by any means.

here's where I am on my Buick build - I'm sleeving the bores, as opposed to boring the motor so that I have a better foundation for the boost I want to run. I did a lot of number crunching and found the hp level I wanted at the RPMs I was willing to run with a 430 ci Buick.....

The guy I bought the motor from was master of the junkyard turbo - at the time I bought the motor, he was running a 350 with a john deere turbo in a mid-60s chevrolet truck. As I told you before, he was selling the 400 because he couldn't keep them together at 16 psi, he kept blowing head gaskets. I figured, wrongly, that since I wasn't going to be more than 6-7 psi it wouldn't be a problem.

That said, it wasn't the boost - it was one cylinder getting lean from a vacuum leak on the intake that caused the destruction. Boost didn't destroy the motor, it merely accelerated and increased the destruction.... that said, the forged rods, 6 forged pistons, and the rest of the ARP stuff I put in the bottom end look pristine. After all, it might have had 1000 miles on it. I wish I had known you were looking for 400 parts, I have a 2 bolt block and quite a bit of 400 stuff (SFI damper for example)...

Only reason I posted up a picture now - I needed the pan off the motor and had never posted pictures of the block... figured it'd be a two-birds, one-stone kind of deal.

[TheSilverBuick]

In all fairness, I've had the same cam since summer 2011 =P

[Beagle]

the GM is a Push fork? Make a bracket for the transmission or bolt to bell and use a pull cylinder?

http://www.speedwaymotors.com/Speedway-Pull-Type-Slave-Cylinder,7169.html

35.00 ?

Teddyzee has a good rear mount (his is push, but still) design on his T5 setup.

[SuperBuickGuy]

the GM is a Push fork? Make a bracket for the transmission or bolt to bell and use a pull cylinder?

http://www.speedwaymotors.com/Speedway-Pull-Type-Slave-Cylinder,7169.html

35.00 ?

Teddyzee has a good rear mount (his is push, but still) design on his T5 setup.

I ordered the push version of that..there's tons of room in front of the transmission, but little room behind the arm. Crossing my fingers that it does get here on Thursday - otherwise no race on Sunday.

[milner351]

that's what I was going to suggest - go with an external slave cylinder - given the side pipes you should have lots of room - are you replacing the clutch disc? (spoiled by brake fluid?)

[SuperBuickGuy]

that's what I was going to suggest - go with an external slave cylinder - given the side pipes you should have lots of room - are you replacing the clutch disc? (spoiled by brake fluid?)

I pulled the pressure plate, the clutch disk is fine, no hot spots and no soaking

cross your fingers - Thursday is make or break day