[Manic Machinist]

Interested in hearing about your 427 BBC combo's, especially VegaEddies 9.80 set-up. A friend of mine just got his car together and has a 433BBC, mid 80's Cutlas, backhalf with 32" tires, and I think it weighs about 2900ish with driver. Engine has Dart 320's, not sure about the cam, but dynoed about [email protected], dont know about the torque #'s. Engine will go to 6000 against the converter.

Its supposed to have a 5.13 gear in it, but shifts way down track at 7000rpm. At first I thought he might have too tight of a converter, but on his 1st outing(i was not there btw) yesterday, they kept moving the launch rpm up each pass and would see a lil improvement(which indicates too loose of a converter, right?)
. The last pass was up against the converter @ 6000rpm and ran a 6.69 with only a mid 1.50 60'. The other 60's were slower. He said he was at 6000 at the finish line.

Now I think he may have too loose of a converter and not enough gear(like-maybe its not a 5.13 gear) He bought the car rollin' and I dont know if he verified the gear.

What do you guys think?

 

[VegaEddie]

.060" over 427, GM crank, Eagle H-beam rods, TRW 13.1 pistons, Lunati .722/.722 solid roller, ported 990 castings, port matched Victor 454R manifold and a 1050 Dominator.

The cam that was in the engine was actually ground for a 500" alky engine and was a bit big for the 427. The lift was OK, but the centerline was too much. A cam in the 268/272 range would have been MUCH more appropriate in this size engine (and probably picked the car up 2-3 tenths). I launched at 5200rpm and shifted at 8000rpm. Car weighed 3040lbs, 8" converter, 'glide, 4.88 gears and 14x32 Hoosiers. IIRC, the best 60ft with this combo was 1.37 or 1.38.

 

[bracketchev1221]

Now that I'm home I'll list it. 427 +.100"=447

13.5-1 Venolia pistons on +.100 longer Carillo steel rods and stock crank. .680/.680 lift Comp Cams roller cam. Sorry I can't be more specific it was over 20 years ago. Chevy D port aluminum heads with a holley strip dominator and an 850. This was in a back halved 68 nova. The car had a powerglide and a Transmission Specialties spragless converter. Leaving at 3500 it went consistant mid 1.30's in 60' with a 1.32 best at Atco with a 9.65 best. Like I said in the other post, this was a 14X32 Firestone tire on 12" wheels, with 5.13 gears shifting at 7500 and crossing around 8000.

 

[Manic Machinist]

Thanks Guys.

Sorry Eddie, I guess the link or forum woulda been helpfull. lol

When you guys say your launching at 3500 or 5200, where was the converter actually coming in?

Here is a vid.

 

[VegaEddie]

I had the two-step set at 5200rpm, and it really wasn't banging away on the two-step hard at all. 5200 is about as much stall as I was going to get out of that particular converter (and that cam). Again, a tighter centerline would have really helped make more torque and therefore more stall speed.

 

[Manic Machinist]

I had the two-step set at 5200rpm, and it really wasn't banging away on the two-step hard at all. 5200 is about as much stall as I was going to get out of that particular converter (and that cam). Again, a tighter centerline would have really helped make more torque and therefore more stall speed.

Thats interesting info right there. Mike, the car owner/driver, found his best 60' and et by turning the 2step off, and going straight off the converter. In the video, you can hear it pull the motor down before the rpm's star to climb, and the shift is quite a ways down track. I believe he was shifting at 7000, and i think some higher shift points are in order, but I dont know the history of the motor and dont wanna have him takin' it to 8000rpm b4 I get a chance to check the lash and valve spring pressure, and get some details on the timing events of the cam.

Thanks again guys. Hopefully we can get him runnin' some 6.20's before too long.

 

[JHaleyH374]

Sounded like either the transmission or torque converter was slipping pretty bad. Either that or like you said above he doesn't have the gear he thinks he has. But it's a cool car! I'm sorta fond to the mid-80's Cutlass :-D

 

[bracketchev1221]

If I remember it was supposed to be 5500 on the converter, but my father never checked the true stall. He wasn't concerned because he said the car left the same at 3500 or 5000, so he left lower. But then there were no 2 steps. He would bring it to 3500 on the transbrake and then punch it when he let the button go.