Got the '69 back running again.

[69427]

I finally got a few of the minor projects done enabling me to fire the engine up again. I haven't started the thing since I took it out of the trailer after the fueling (leanout) issue I ran into during a session at Gingerman Raceway with some friends from Indiana last September.
A couple of the minor items I worked on was relocating the battery to the RH storage compartment. This took 26 pounds of weight off the left side, and the new, lighter weight battery added 17 pounds to the right side for a net reduction of 9 pounds. I moved the alternator to the right side also, taking 14 pounds off the left side, and adding 13 pounds onto the right side (the new bracket was a pound lighter). I needed to make an extension harness to reconnect everything, so I think the total vehicle weight was unchanged, just redistributed. I installed the '79 driver's seat (that I got from Karsten), along with custom brackets I made, and took another 15 pounds off the left side. (I haven't had time to work on the other seat yet.) The "new" later model p/s pump seems to be okay (noise-wise), with a net weight reduction of another 7 pounds off the left front. I still need to drive the car to see if the pump flow is sufficient to allow quick steering maneuvers. And last, and certainly least, the new (aluminum) air filter base takes one pound off the highest point on the engine.
Net weight reduction with these changes is 32 pounds. Regarding the weight shift, I took 62 pounds off the left side, and added 30 pounds to the right side.
I'm hoping to remove another 10-15 pounds off the car with the new muffler and the new radiator support.
I can't stuff as much tire in the wheel well as I'd like for good cornering, so I'm hoping to somewhat compensate by reducing the mass of the car, and improving the distribution of the weight I'm stuck with.

 

[73c34me]

sounds great! I would like to move my my battery to the rt. side as well. any details to share?

 

[SmokinBBC]

Did you ever figure out why it leaned out on you?

 

[69427]

Did you ever figure out why it leaned out on you?

No, still a mystery to me. It did run like a champ after getting bounced around in the trailer on the way home, though. So, after that I rebuilt my spare 850 DP and I'll just carry it with me in the trailer in case I have some issues again. Doesn't take more than about 15-20 minutes to swap the carb, and then hopefully I could still salvage some track time that day.
If I get caught up with things down the road perhaps I'll take this carb apart too and see if I see anything suspicious in there.

 

[69427]

sounds great! I would like to move my my battery to the rt. side as well. any details to share?

Things went easier than I thought it would. No drilling or cutting required for what I did. I went with a smaller battery than the original to take off some weight. This allowed me to use the jack "anchors" along with some battery "J" bolts and a cross bracket to fasten it down. I ran the ground wire through the drain hole at the bottom of the compartment and tapped/bolted the ground cable to the frame similar to how the original was done on the left side of the car. I also ran a "short" positive cable from the battery to under/behind the center compartment and through to the original battery compartment where the positive cable still resides. (The compartments aren't "sealed", as it were, and you can run the cable from one compartment to another.) I then attached the two positive cables together and voila', it all works.

With this arrangement I have the option of keeping the (bigger) original battery in the original location for street use (or NCRS judging ) in case I leave the lights on or something stupid, and also being able to remove the original heavy battery in just a couple minutes for autocross/track use.

 

[larrywalk]

Nice job! I'm thinking of doing the same to even out my 4 wheel weights.

 

[69427]

Track day at Heartland Park Topeka

Spent the day having some fun with the '69. Superior Chevrolet in KC hosted a bunch of the activities at the track, and treated us extremely well.



I was interested in some tuning time for the car so I left the sticky tires at home and just took the 255/16 street tires off the '84 while the '84 is down due to an injector failure.
The lightweight battery I put in the right side (jack) storage box worked well all day, as I had to start it several times during the day for tech and moving it around. I was real happy that that inexpensive weight reduction/relocation went well.
First session out the car ran well during the warm-up lap, and then just fell on its face during medium load conditions. Light load or WOT it was okay. Damn, I'll bet that same issue I ran into at Gingerman occured again. I babied the car back to the pits and pulled the (780 VS) carb off and put the spare 850DP on. Started right up and idled well, surprising the crap out of me. Went back out on the track the next session and holy shit that thing ran strong. I was never in a big rush to put the 850 on the car as I didn't think there was that much performance difference between those two carbs (my focus the last couple years has been taking weight out of the car). I'm convinced now, so I'll pull the 780 apart and fix it for a spare.
My compliments to Tom DeWitt. I have one of his aluminum radiators in the car (to take off some weight primarily), but that thing worked very well today. The air temperature was 99 degrees according to my truck's digital thermometer, and the '69's engine stayed between 210 and 220 during the sessions (I compared the temp gauge reading with an infrared gun I have, and the temps were very close). I'm running a 195* thermostat and a low-tech (but very light) stainless steel flex fan. All in all I'm happy with the cooling capability.
More to come shortly after this break.....

Edit: Oh yeah, I just remembered. Last winter during a thread discussion about C3 front-end lift I decided to try an experiment. I made some plastic blockoff plates and put them in the two outer grills in an attempt to divert some of the incoming air out to the side of the car, and hopefully encouraging (due to a slight pressure reduction in the pre-radiator area) the air to come from the front spoiler area instead. Hopefully this would reduce undercar flow and front end lift. Admittedly I was busy today trying not to run off the track, but the car felt very stable, and the blocked off grills did not cause a cooling issue, even at the ambient temperatures we were running in today.
Handling-wise the car felt very neutral and predictable, reminding me why I loved the handling of my (Z-51 equipped) '84, and affirming that all the work to reduce the vehicle weight and update the suspension was worth all the work (and head-scratching at times).
The Wilwood brakes worked very well (I had more brakes than tires) with no fade, but I think I'll try to direct a bit more air to the rotors for good measure.
The "new" (late '80's GM) lighter weight power steering pump worked well, with only slight fluid bubbling. I'm not sure if it was a fluid issue (just have regular fluid in it at the moment) or if it was slightly overfilled. I've got some synthetic stuff on the shelf, along with a C5 p/s cooler, so when time permits I'll upgrade the system a bit.
The new muffler was an amusing experience. Sounded nice at WOT, but I'm going to see what I can do for a version 3 that will be a touch quieter at slow speeds. I welded in a fitting to hook up a pressure gauge to measure the backpressure, but didn't have time to complete the gauge installation.



The "engine by Mike" actually stayed together, so that was an encouraging thing, along with the rest of the car, other than the carburetor issue.
That's the highlights I can think of at the moment.

Edit 2: I installed a '79 seat that I got from Karsten to see if I liked it enough to spend the money on getting it re-covered in blue to match the interior. All in all the seat was very comfortable, and had more support than the stock seat had. I anticipate looking for some upholstery specials and getting the seats redone. Thanks Karsten!

 

[TimAT]

One of these days I'll be home when Heartland Park has a track day. Ol' Red needs to get out there and get all limbered up.

I'll agree with the 850 carb waking things up. I had a 750, went to the 850, the difference is unreal. I keep thinking about the Edelbrock 2x4's too. A pair of 650's the PO had on there. I drove it way before I got it with those carbs- It really likes the more CFM..

 

[mrvette]

I not seen dual quads on a SBC in years, decades even....bet it's tough finding a mani for that anymore.....

 

[68/70Vette]

Looks like you've got a Richmond tranny. 5 or 6 speed? Also, I noticed you have a removable crossmember. Was your car originally an auto tranny car? Looks great underneath (topside also). The muffler looks interesting. Have you described it on another thread? Your attention to detail is impressive. And of course......what's the new bottom line on weight? Thanks

I'd like to have the crossmembers on both my 68 and 70 altered to be removeable. I've already bought the crossmember from an auto and also the frame brackets.

 

[69427]

Looks like you've got a Richmond tranny. 5 or 6 speed? Antique Doug Nash 5spd. :wink: Also, I noticed you have a removable crossmember. Was your car originally an auto tranny car? No, I just didn't want to cut up the stock frame (as it was in good shape) to get that damn large trans out every time I needed to do some trans or clutch work, so I bought a used auto frame and swapped the body over. Looks great underneath (topside also). The muffler looks interesting. Have you described it on another thread? IIRC there's some posts buried in one of my threads about future projects. I'll try to find it and reference it. Your attention to detail is impressive. Thank you! And of course......what's the new bottom line on weight? Thanks Edit: Found the muffler thread in the Projects section.I'd like to have the crossmembers on both my 68 and 70 altered to be removeable. I've already bought the crossmember from an auto and also the frame brackets.

Last year I weighed the car (less driver and minimal fuel) and got 2910 pounds. I did some things over the winter and pulled about another 30 pounds out of it, but haven't had the opportunity to weigh it this year. I still plan on putting the rear bumpers back on when I get caught up with other stuff, so that will put about 25 pounds back on it. I have a couple more items planned, but they might have to wait until winter so the car isn't torn apart during prime track time.

 

[TimAT]

I not seen dual quads on a SBC in years, decades even....bet it's tough finding a mani for that anymore.....

I'd have to do some serious mods to fit a SBC 2x4 manifold on Ol' Red's BBC. But it might help with hood clearance- it'd be really low. Almost need updraft carbs?

:mobeer::harhar: