548 CI BBC Advice

General engine tech -- Drag Racing to Circle Track

Moderator: Team

Post Reply
cstraub
Guru
Guru
Posts: 1063
Joined: Wed Feb 18, 2004 5:30 pm
Location: Tri-Cities, TN
Contact:

Re: 548 CI BBC Advice

Post by cstraub » Tue May 16, 2017 5:28 pm

TBART1970 wrote: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.
Chris Straub
Performance Mfg.
http://www.straubtechnologies.com
www.distributorgears.com

User avatar
FC-Pilot
Pro
Pro
Posts: 216
Joined: Tue Mar 17, 2009 2:23 pm
Location: Peoria, AZ
Contact:

Re: 548 CI BBC Advice

Post by FC-Pilot » Tue May 16, 2017 7:12 pm

TBART1970 wrote: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
"The latest tests prove exactly what my money tells them to prove".

TBART1970
Member
Member
Posts: 64
Joined: Wed Feb 08, 2017 9:16 pm

Re: 548 CI BBC Advice

Post by TBART1970 » Wed May 17, 2017 6:17 pm

Back from page two.
TBART1970 wrote: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
Member
Member
Posts: 64
Joined: Wed Feb 08, 2017 9:16 pm

Re: 548 CI BBC Advice

Post by TBART1970 » Tue May 23, 2017 12:21 pm

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

cstraub
Guru
Guru
Posts: 1063
Joined: Wed Feb 18, 2004 5:30 pm
Location: Tri-Cities, TN
Contact:

Re: 548 CI BBC Advice

Post by cstraub » Tue May 23, 2017 12:22 pm

TBART1970 wrote: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.
Chris Straub
Performance Mfg.
http://www.straubtechnologies.com
www.distributorgears.com

TBART1970
Member
Member
Posts: 64
Joined: Wed Feb 08, 2017 9:16 pm

Re: 548 CI BBC Advice

Post by TBART1970 » Fri Jun 09, 2017 8:58 pm

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
Member
Member
Posts: 64
Joined: Wed Feb 08, 2017 9:16 pm

Re: 548 CI BBC Advice

Post by TBART1970 » Sat Aug 05, 2017 8:43 pm

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
You do not have the required permissions to view the files attached to this post.

fdicrasto
Expert
Expert
Posts: 538
Joined: Wed Sep 26, 2012 3:44 pm

Re: 548 CI BBC Advice

Post by fdicrasto » Sat Aug 05, 2017 11:35 pm

Why not. 820-840 hp.

TBART1970
Member
Member
Posts: 64
Joined: Wed Feb 08, 2017 9:16 pm

Re: 548 CI BBC Advice

Post by TBART1970 » Sun Aug 06, 2017 9:26 pm

fdicrasto wrote:Why not. 820-840 hp.
Is that a serious, calculated guess?

TBART1970
Member
Member
Posts: 64
Joined: Wed Feb 08, 2017 9:16 pm

Re: 548 CI BBC Advice

Post by TBART1970 » Mon Aug 07, 2017 8:07 pm

No guesses?

User avatar
MadBill
Guru
Guru
Posts: 12614
Joined: Tue Nov 15, 2005 10:41 am
Location: The Great White North

Re: 548 CI BBC Advice

Post by MadBill » Mon Aug 07, 2017 9:40 pm

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.
Felix, qui potuit rerum cognscere causas.

Happy is he who can discover the cause of things.

TBART1970
Member
Member
Posts: 64
Joined: Wed Feb 08, 2017 9:16 pm

Re: 548 CI BBC Advice

Post by TBART1970 » Mon Aug 07, 2017 9:55 pm

739.9 hp at 6000
727.8 tq at 4800

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

User avatar
MadBill
Guru
Guru
Posts: 12614
Joined: Tue Nov 15, 2005 10:41 am
Location: The Great White North

Re: 548 CI BBC Advice

Post by MadBill » Mon Aug 07, 2017 10:01 pm

Well at least I got the peak revs right... #-o
Felix, qui potuit rerum cognscere causas.

Happy is he who can discover the cause of things.

TBART1970
Member
Member
Posts: 64
Joined: Wed Feb 08, 2017 9:16 pm

Re: 548 CI BBC Advice

Post by TBART1970 » Mon Aug 07, 2017 10:08 pm

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
Guru
Guru
Posts: 1063
Joined: Wed Feb 18, 2004 5:30 pm
Location: Tri-Cities, TN
Contact:

Re: 548 CI BBC Advice

Post by cstraub » Tue Aug 08, 2017 9:57 am

""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.
Chris Straub
Performance Mfg.
http://www.straubtechnologies.com
www.distributorgears.com

Post Reply