Thread: Advice on combo

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Hey guys, been reading other treads, and i,m impressed with the advice many of you have offered others on their builds. I have a combo, not built by me, and i thought i'd throw it out there, and see what you guys think. i,m not a motor builder, but do know a little. i'm sure this can be improved on, so what do you guys think. the motor is a sbc 350 4 bolt,stroked to 396.the block is bored .030 over, scat crank ground for small journal rods.@ 3.850 stroke, 5.7 rods, and 383 pistons that had the domes milled off to make flat tops at 0 comp height. I know the rod angle sucks, and the comp figures out to 10.6-1, .040 head gasket. the heads are the old 190 AFRs, 202s with mild porting, the cam is a comp solid cs 6014 534 lift and dur at 250/250 at .050 with a 106 center line, lobe separation at 110. installed straight up at 0. the kit was installed and set up by Rick King, a local drag boat engine builder. rockers are 1.5s, intake is a wiend tunnel ram with 2 600 holleys with vac secondarys. ign is Msd with 6al2 box. headers are modified 1-5/8 block huggers with 2-1/2 pipe through dynomax super turbos. ( kinda stuck with this exaust as this is a street car, and i need to be able to work on it) the trans is a turbo 350, rebuilt with a b&m kit to b&m specs. street strip style. and a converter shop 3500 stall, 411 posi, mini tubbed with 28x12 tires on leaf springs, with traction bars. all this stuffed in a 72 vega. the car does run very good, just thought i'd see what you guys had to say, I've always felt with the small exaust, maybe the stroker block is to much, should i build a 355 ????? ummmmm just throwing it out there for fun, if you guys want to play, hit me, i can take it thanks Tony

It sounds fine as it is a street car....you might be leaving a few hp on the table with the smaller exaust....but not enuff to worry about on a street rod.

You could always come off those headers with a 3 inch pipe to help some...not sure if they make 1 3/4 inch or 1 7/8 inch shorties or not....if it runs fine and you do not run at the track I would not worry about it.

If anything that tunnel ram is leaving more low rpm torque and hp on the table than those headers...unless you are running a huge stall converter or run it up to 7 or 8 thousand rpm all the time.

If you have a 4500 rpm stall and spend alot of time in the higher revs ,then yes the exaust is holding you back some.

Judging from the picture, that engine is completely unsuitable for your purpose. I suggest you ship it to me for further analysis....

I had a tunnel ram on a street rod ten years or so ago, and I can tell you that when I switched over to a single 4 bbl carb, I was amazed at how much snappier the throttle response was. But that is the trade-off for the bling factor a polished tunnel ram will give you. Yes, you would probably gain some hp by going to Sanderson's 1 3/4 inch shorty headers, 3 inch exhaust and straight-through mufflers like Dynomax Ultraflows. But IMO, since this is a street car, the difference would not justify the price. Nice engine bay, by the way. Keep the stroker. There is no substitute for cubic inches.

I'm with Rumrumm - the tunnel ram may be casting you some low end, but it sure looks cool. A polished Performer RPM and a Qjet would probably give you a bit more snap, but it certainly would mean spending some money, however the tunnel ram set up would probably go in a heartbeat on Craig's List or E-bay.

Nice looks and by the way, it sound's like you understand more about your engine setup than you're taking credit for!

Great to have you on the site and we'll look forward to your posts!

Regards,
Glenn

Thanks for the input guys. The exaust just cant go bigger. I had bigger on another car, and hated it when it was time for plug changes, and this engine bay is just to small. I also have a RPM Performer manifold / with a worked over 780 double pumper. and it does have a snapier bottom end, but doesn't have the pull power through the gear like the tunnel does, maybe it would with a bigger carb???? The bottom end isn't bad, this is a small car, and tends to have traction problems, on street tires, never tryed slicks. T.