Captain bob

i have listen to my brothers on this forum and feel i have made a mistake.i built a 408" sbc with all forged short block,AFR 195 heads,1.6 dollar rockers.lunati rollar cam,air gap rpm manifold.labor no object machine shop time no object ,balance to 1 gram,all the best CNC bored and surfaced dead nuts.10.6 compression,.005 deck height.Molodon 7 qt pan,HV pick up and pump.first question; i used Lars ignition timing with empty HEI just a pick up i use MSD to fire.i put rubber band on HEI weights then disconnect vacuum disregard initial timing and take it up to 2500rpm and set at 36 degrees .initial was 23 degrees at 1000 rpm.i feel this is high when connected with vacuum advance it comes out to 54degrees.i put on road -------------ridiculous 3.55 rear with turbo 400 1st gear (700R4 on bench)spins goodyear radial 225/r 15 like i had bicycle tires .i do i calm this monster down! will dangerously break wheels loose in normal passing situation.

Captain bob

Captain bob

TimAT

The rubber band on the HEI weights confuses me. I admit I'm confused easily, but I just don't get that one.

Captain bob

i should mention i must retain nostalgia look with 15" tires and oem. rims. the car has all new suspension with bilstein hd shocks all around.

Captain bob

the rubber band around weights ensure there is no vacuum advance what so ever with vacuum disconnected to effect your 36 degree mechanical advance setting.

ezobens

I think you have that backwards-
The weights have nothing to do with vacuum advance, they control mechanical advance only.
Putting a rubber band around the weights will prevent mechanical advance only. Also, I'm not sure I'd leave the rubber band as a permanent solution as it will deteriorate and break after a period of time.

Captain bob

i guess i did not explain myself.the rubber band is put around the weights on distributor shaft ONLY to set timing then it is remove and connect vacuum hose to check TOTAL ADVANCE which consist of initial/mechanical/vacuum. sometimes if you use "gold" very light springs the vacuum with start coming on at idle you what to avoid this.

LT1driver

no such thing as too much HP...., just a problem putting it to the ground

ajrothm

Get you a set of Nitto 555R drag radials in a 275/60/15, put them on your stock ralley wheel and let it eat.. It will still blow them off from a dead stop but from a 20 mph roll, it will hook on them.

Blue79

Well, if you're serious, you can do like the factory did in the 70's, and retard the f**k out of the timing. That should make 'er run a little doggy. Not to mention possibly cleaning up emissions a bit. But that's just my take.

leadfoot4

As "ajrothm" said, just put some tires on it!! A 408 stroker on 225/70s ????

Gordonm

Not to much HP. Just need to be able to hook it up. Better tires and don't stab the throttle. You have to learn how to drive it. Roll Into the throttle instead of stabbing it.

holley505

I run 275/60R15 M/T on the back of my C3.... It will Break Loose if I put it to the floor. Make cool smoky burn outs into 2nd gear. And If I feather it just right... I can run 10s in the quarter.

But you need to learn to drive it with the extra power... know the limits and stay away from rain and wet roads.

The Money Pit

I run MT 295 55 15's to cure that "little problem" you mention. Also am running 36 degrees timing locked out in my 406.

Still have to ease into the throttle from a dead stop, but that hula dance I used to get hitting the gas hard from a 45 mph roll with street tires is gone.

Captain bob

the fear i have is put her to the floor on take off and when it shifts into second the car goes completely side ways out of control on one lane road. Previous to this c-3 i had three 1967 c-2 in a row all big block the conv.was 427-390hp,then coupe 427-435hp then a NCRS 427-400 with 3.70 gears this 408" literally blow the doors off those big block cars in brute torque and instant ability to rev up. you guys hit the nail on the head. i have to some how learn to drive it.my long time friend try to guide me and remove hp (no single plane riser manifold and 600 lift cam with 290/295 at .050 . this is a street only car.besides the insane torque i was surprised the vacuum is 17hg at idle with holley carb adjusted low speed perfectly.one side note those AFR with CNC intake port ,exhaust ports and CC are a work of art.somebody told me they make exact copy of rally wheel in 10" i don't no this to be true.years back i had the unfortunate experience of a 82 collectors edition breaking loose and spinning out of control into a pole with rear tire slamming into pole total the car and left a warning in my brain.the job went smooth took about 5 hours to install because i had to jack front way into the air to put headers in almost vertical to clear steering box and also remove drivers side valve cover.

Jamess411

You could always sell the engine to me??? lol j/k

Captain bob

strictly speaking as a casual observer when richie from PCHS racing engines assemble the short block and insisted he would use his parts the forged crank had holes thru the crank throws and throws we also knife edge.this along with 6" HP. damper and moroso hp. flex plate.H beam 6" rods add tons of torque and Richie Zull insisted on them along with those forged light weight piston with 3/16" hand filed rings and special roller chain from germany. apparently i guess this is what makes this engine go from 1000rpm to 6000 rpm in seconds. i agree sort of a waste for a sunny day summer joy ride car.

jb78L-82

I understand completely where you are coming from with a C3! For a strictly street driven C3, the chassis and tires pretty much limit the amount of real usable HP/torque you can use on the street with street tires. Nonetheless, as others have noted, rolling into the throttle rather than hammering the throttle to the floor, should make the car very drivable-just be careful.

Because of my driving experience with my 10Z06 and the explosive power from the LS7, when I was planning the rebuild of the L-82 last Spring 2014, I was not concerned with building a monster 355 L-82 or even a 383, since after experiencing 450 RWHP in the Z06 in a much more sophisticated suspension, very light car 3,100 lbs with a MUCH bigger tire on the C6Z06, I was more interested in trying to build a powerful mid range HP/torque L-82 block and components than all out high RPM power. To that end, I too used the AFR heads BUT passed on a higher duration roller cam with more lift (.525/.525, duration 219/225) instead of .550 lift and 225/230+ duration) to create strong mid range torque-its very strong BUT street able. I even reused the L-82 aluminum intake with my Holley 4175 650 CFM vacuum secondary Qjet replacement on the car since 1985 with the stock OEM dual snorkel cold air cleaner assembly. I am going with ARH LTH in the Spring to maximize the exhaust and looking for 450/450 Gross HP/Torque in the end after dialing in everything. The car is only street driven on street tires (although MUCH better tires than 15's-255/45/17 ZR ultra high performance summer only tires). I feel that 350+ RWHP should be perfect for the old C3, not to mention I am not interested in breaking the Super T-10 4 speed, rear diff, halfshafts etc…just me.

MrJlr

You could put a much smaller carb on it