548 CI BBC Advice

[cstraub]

Distributor not in far enough.

I appreciate you posting this. So many times the lifter gets blamed for the issue when in fact, as in this case, it is actually the lifter being abused because something else is not correct in the engine.

[FC-Pilot]

Distributor not in far enough.

Thanks for sharing this. It is never easy to admit that we makes mistakes some times, but the hope is that others will not make the same mistake that we do. Hopefully this will help others to make the same mistake. I know I will double check from now on.

Paul

[TBART1970]

Back from page two.

Issues should be good to go on pressure, first pump was Moroso billet pump, standard volume, dyno intake and dist. In the car Injected intake, different dist. Had pressure problems from beginning. Pulled the engine put in Titan gerotor pump, slightly better but still an issue. Titan pump has a different drive at the pump and I made the mistake twice of not checking the distributor/ gear / galley alignment. Mismatched parts and trying to solve it in the car. I will take the blame, my builder is helping me fix this. I assumed (oh boy) that the intake/ distributor would not be an issue.

[TBART1970]

Heads are at Ceralli engines for valve job, and going to John at CFMcnc in Florida.
They need some port work.

[cstraub]

Heads are at Ceralli engines for valve job, and going to John at CFMcnc in Florida.
They need some port work.

Bill Cerrelli is good people.

[TBART1970]

Valve job alone made better flow #s. Porting made even better gains in CFM, without adding much CSA, according to the cylinder head guy. Thanks to John at CFMcnc head porting. Looking in to getting another cam (Cam King are you listening). When the heads get back to Ceralli, they will get milled and re-flowed with the intake manifold. Then I will decide.

[TBART1970]

anyone like to guess at the dyno numbers? New compression ratio 10.24 to 1

IMG_20170805_192638298 eng2 (2).jpg

IMG_20170628_160139853 eng3 (2).jpg

[fdicrasto]

Why not. 820-840 hp.

[TBART1970]

Why not. 820-840 hp.

Is that a serious, calculated guess?

[TBART1970]

No guesses?

[MadBill]

It's like a woman asking you how old you think she is. Honesty is not the best policy. If you subtract too many years from your answer she knows it's B.S. but she doesn't mind. Thus the easy path is to go low on age, high on HP.

So here's me not taking my own advice: 790 HP @ 6,000, 750 lb-ft. @ 4,800.

[TBART1970]

739.9 hp at 6000
727.8 tq at 4800

I was hoping for 700-715. I am happy.

[MadBill]

Well at least I got the peak revs right...

[TBART1970]

Thanks everyone for all the help. Letting me know about the head flow deficiency and cam advice.
Now to get it back in the car and start tuning again.

[cstraub]

""Hello everybody, I have a 548 CI BBC, New Gen 5 Bowtie block, 4.600 bore, 4.125 stroke, 9.7 :1 compression. I was with the engine builder every step of building this thing. It had a Straub Technologies custom Hydraulic Roller cam with Morel hydraulic lifters. On the dyno with a small intake and 850 carb it made 690 hp and 750 ft. lbs. torque."

Tom,
So you lost power over my smaller cam. If dyno'd with the larger intake and larger carb based on the Ft/lbs of torque you would have made more HP also.