Project C4, 85 Corvette

[Goodspeed]

btw there is a guy who runs most carguys events with a silly high hp C4 vette too

At VIR last weekend, there was a red C4 (70x) that didn't look quite as insane as this car and he was hitting 165 on the straight hock:

[Mike]

iono, my car is between 8s and 9s and i rarely see 125mph w/ 2100lbs to stop.

i've run 9s without problem... in your case, i'd rather be safe than sorry... however, even with 8s, you're gonna know well in advance if you're gonna run in to trouble. might want to have some "bigger" pads on hand... you're gonna need them eventually. if you don't feeel like grabbing some spares, it's as simple as backing off when you hit the straight... there's not learning to be had blasting down a straightaway.

[Steve85]

iono, my car is between 8s and 9s and i rarely see 125mph w/ 2100lbs to stop.

I don't see 9's on their site? At first I thought you meant to say 10's....

in 40-50 degree weather you will be more than fine on XP8. just make sure you bed them in well at least a day in advance.

btw there is a guy who runs most carguys events with a silly high hp C4 vette too

Good to hear on the 8's, and like Mike said if they start to go away just pull back a little more.

Cool..It would be nice to talk another C4 guy at the track about setup and stuff.

[Mike]

iono, my car is between 8s and 9s and i rarely see 125mph w/ 2100lbs to stop.

I don't see 9's on their site? At first I thought you meant to say 10's....

I would recommend 10s for you... i was just giving my experience.

[Steve85]

iono, my car is between 8s and 9s and i rarely see 125mph w/ 2100lbs to stop.

I don't see 9's on their site? At first I thought you meant to say 10's....

I would recommend 10s for you... i was just giving my experience.

Yeah, I was just curious where the 9 came from, I dont see it as an option on their sitethats all.

I will likely order the 10ÔÇÖs today, if I donÔÇÖt use them next weekend I will certainly use them in the future. I certainly appreciate the advice.

[Evan]

9s were discontinued because they sucked.

[Steve85]

I had to fix a couple issues that thankfully happened together on the track.

I disassembled the crankcase vac pump regulator so I get max bleed off which seems to work great. No more blowing oil out of the catch can.

It turns out that my PS pump leaked. I thought I had oil on the belt causing it to slip and a loss of PS. When I got the car home I realized the PS reservoir was empty. All this happened while braking after T4, thankfully a very slow point on the track for me.

I replaced the PS pump and the aged high pressure hose.

I took it out for a spin and it died at a stop light. I thought my distributor might have taken a dump again but it turned out to be a bad crimp and broken wire from the battery to MSD box.

So maybe if I donÔÇÖt drive it it will survive to the show.

Next project wilol be brake cooling ducts...

[D_Eclipse9916]

I had to fix a couple issues that thankfully happened together on the track.

I disassembled the crankcase vac pump regulator so I get max bleed off which seems to work great. No more blowing oil out of the catch can.

It turns out that my PS pump leaked. I thought I had oil on the belt causing it to slip and a loss of PS. When I got the car home I realized the PS reservoir was empty. All this happened while braking after T4, thankfully a very slow point on the track for me.

I replaced the PS pump and the aged high pressure hose.

I took it out for a spin and it died at a stop light. I thought my distributor might have taken a dump again but it turned out to be a bad crimp and broken wire from the battery to MSD box.

So maybe if I donÔÇÖt drive it it will survive to the show.

Next project wilol be brake cooling ducts...

hahah I know how you feel, comes with adding stuff to the car and dealing with stock maintenance issues too. At least your sorting stuff out now and not missing out on too much track time!

Oh and where did you get your roll bar built??????

[Steve85]

Roll bar is a sore spotThe guy is great with muscle cars but screwed me pretty good. The swing outs were the wrong style mounted in the wrong place, the harness bar is too far forward, lost 3 inches of rearward seat travel, the rear down bars should go to the wheel humps not the middle of the floor.

So, you donÔÇÖt want to use him.

We have AR Fabrication here in Winchester and you can always talk to the JL Fabrication in Harrisonburg. Drop by one day to JL (1187 N. Liberty St) and talk to Rob or Jamie.

[Steve85]

I love taking off the targa but with a roll bar in these cars it blocks the storage brackets. So I came up with a solution.

I started with these parts. The plates were welded to the little V which was modeled after the the parts of the top that will rest inside the plates. These V's were welded to the down tubes from roll hoop.


The front of the targa has a hole that this pin goes into to hold the front in place. I was just barely able to reuse it. The top is supposed to install at a diff't angle, any more and the trim would have interfered.


I had to add a plate to the V's to raise them a little or the top would have rubbed on the down tubes. The plastic top would have lasted all of 3 bumps banging against the bar.


I will probably add some sort of strap attachment to keep it more secure...something with a little buckle.

I REALLY like having this welder. I love coming up with these types of solutions and now, actually being able to execute them.

Here's my sketch pad. It was neat to play with the settings and see the effect of bead size and penetration.

[Steve85]

Father's Day presents:

Oil pressure - pretty much since the beginning this engine has struggled with it. Never getting over 35 and after a while of driving down to 12 at idle.

Smoke removal - again since the beginning, bluish white smoke from the exhaust, quite a bit. Maybe that's where my oil pressure is, in the combustion chamber.

Lower temps - because it's a carb manifold with injector bungs, holes that would be used to bring coolant to the rear of the heads are being used for temp sensors.

I am more than disappointed with the original builder who did the manifold conversion and the short block assy. They had problems getting the block from Brodix, serious delays in the build due to turnover and starting a trucking company and so on...

So in the interest of time, I have none, and reliability I will have a local shop refresh the motor and it will be run in on their dyno before installation.

[ScottyB]

sorry to hear about that, but hey sounds like the new motor will be done right hopefully

[Steve85]

Son of a ...

Phone message includes the words, "...we're pretty sure it's salvagable. we'd like you to come over and take a look so we can make some decisions"

[Evan]

pics of your vanity plate?

[WRXtranceformed]

Ahhh fuck man that's never what you want to hear. Did they blow it up, or was it damaged before you got it there??

I remember Dave was constantly having trouble with his C4's dart block, but I think he's got it all sorted now.

[Steve85]

I walked into the engine room and I saw a rear main cap sitting on the table with lots of copper showing on the bearing. Then he shows me the pistons and the side skirts look like they have 100K on them because the bores were way too tight (and varied from one to the next). And the list goes on...more wrong than right. The valve seals were at the top of the valves.."I'll bet this thing smoked like a son-of-a-bitch". Yes, it did.

The main bearings are all shot and the Crower crank looks brand new.

So lots of choices to be made. I'm not even sure if I'm gonna stick with this or just put the 408 back in. I'll see what they have to say on $$ Thursday.

[JustinG]

I thought you had a shop build this motor for you???? So it had enough power in its current condition last time you were on track to make you just think it needed a refresh??? Jesus Christ.....

[ScottyB]

at least the crank is OK....those things are (more) expensive.

[Steve85]

I thought you had a shop build this motor for you???? So it had enough power in its current condition last time you were on track to make you just think it needed a refresh??? Jesus Christ.....

I did...a shop in Harrisonburg, Coy Miller (DO NOT confuse them with the shop that did my exhaust, they did an excellent job). I knew I should have taken the parts home when the delays got worse and worse. The new shop asked me if two people built the motor. The variances were that bad from side to side.

at least the crank is OK....those things are (more) expensive.

I almost wish it was toast so I could justify a new rotating assy with less stroke and a better rod ratio. Originally the motor was going to be used for drag racing so endurance / longevity was not a major concern.

[Steve85]

I got the estimate, $5700. I told them to package it up and I'll pick it up Saturday. I will rebuild this as a long term project with some expert help.

But I suffer greatly from the need for IG.

I had the 408 sitting in the garage so I decided to put that back in. It was pretty much straight-forward swap. I rebuilt the heads to clean them up and put in some very high quality valve seals and so on. I also went with a longer runner intake manifold.

The major challenge was the exhaust. I had to make pipes from the headers to the pipes that run down the center.

I started with two bullet cats and two 3" mandrel U-bends and ended up with this...

I made the section for the band clamp to the collector flanges.



Here they prior to install.


Can you guess which one I did first :roll: The top one really was ahack job but a good learning experience.



So it lives again. I can't wait to beat on it tomorrow...