Sbc 350 build for drag racing

[monzter]

I have a sbc 350 engine that I use for drag racing in my 1976 Chevy Monza, the car is 2850 lbs on the line, I know it may seem a bit heavy for such small car, but the car is street legal and gets driven to the local track.
Here are some information about the car, As for now the rear end is Gm 12 bolt with spool and 4.11 gears, 29.5x11.5 hoosier quick timepro tires. Transmission is th-350 with 2400 stall b&m holeshot converter. The engine I had this season was stock bottom end 350 sbc with dish cast pistons aprox. 9:1 compression ratio. The heads are out of the box pro topline 235cc heads with 2.08"/1.6" valves,, and the intake manifold was ported 2101 Edelbrock Performer, on top of that I had 950 cam Holley Hp carb. Headers are 1.3/4" long tubes with 18" collector extentions. The camshaft was this mild solid roller - http://www.compcams.com/Company/CC/cam- ... d=304&sb=2
As you can see now my combo is as mismatched as can be ! But here are the times I ran best this summer..
60 ft - 2.0 sec (which might be because of the low stall converter and big heads.
1/8 et - 7.9 sec
1/8 mph - 93 mph
1/4 et - 12.1 sec
1/4 mph - 117

Unfortunately I broke a piston in this engine so I have already put together another stronger bottom end which consists of stock block with splayed main caps, forged crank and 5.7" h beam rods with arp bolts and forged lightweight pistons that will give the engine 12.5 compression with my heads. So the question is this. I have two camshafts sitting in the garage already and was wondering in I could use one of them in this engine..
1st - http://www.compcams.com/Company/CC/cam- ... d=332&sb=2
2nd - http://www.summitracing.com/parts/CRO-00430/
I also have two intake manifolds that I would like to use, first there is a box stock Edelbrock Super Victor and second is Holley strip dominator. Carb and headers will be reused.
To take care of the bad 60.ft times I have a 8" Ati tree master 5500 stall converter that I will use. Also I want to lower them rear gears but I'm really not sure how low ratio I should go to, but if I remember correctly I was going through the traps at 5800 rpm with the car as it was this season.

Hope you understand this sandwich of mine.
Best regards and take care you all !

[af2]

Forget everything you are thinking and put a minimum of 4000 stall in it and you WILL gain 1second or damn close on the 1/4 mile.

Woops!!! The Crower will be better with a 12.5 350. 4.11 and the treemaster will give you a smile shifting at 7500!!!

I see 10'sssss

[Keith Morganstein]

The crower cam, super victor, race gas. estimate peak hp @ 7300 rpm.

[monzter]

Thank's for your input guys. I then again have one question for you. I see you both advise me to use the crower cam rather than the bigger Comp one. What are the main reasons ?
And what would be optimal stall and gears for either cams. For n/a quarter mile.
And yes, 10's is something to aim for ofcourse !!

Best regards.

[Keith Morganstein]

I see you both advise me to use the crower cam rather than the bigger Comp one. What are the main reasons ?
And what would be optimal stall and gears for
Best regards.

The bigger comp cam will loose HP everywhere in your combo.

your 8" converter is close enough.

gear it for 7900 through the traps.

go to wallace racing and use the calculators.

[af2]

I see you both advise me to use the crower cam rather than the bigger Comp one. What are the main reasons ?
And what would be optimal stall and gears for
Best regards.

The bigger comp cam will loose HP everywhere in your combo.

your 8" converter is close enough.

gear it for 7900 through the traps.

go to wallace racing and use the calculators.

Another thing is looking at the heads but using the Super Vic is close to what I am running. But I have 377 ci with a Motown 4500 intake with a 1050. The duration on the comp is 10 degrees more than what I run and I shift at 8500.
I know Joe will beat me up but there comes a point the big duration won't fit the induction.. As far as stall?? 5500 plus to get the car to launch with that Lunati cam..

Oh yea gears. Run the 4.11 then you can decide to run a 4.88 or lower at a later time.

[monzter]

Thanks again my friends.
Now i have been playing a bit with the calculators at Wallace racing and one thing i'm wondering about is Converter slippage. what is acceptable slippage at high end and what should i use for guidelines (as trying to figure out what might be a good gear ratio) since i might be leaving something on the table with these highway gears, as stated above. But i think i will go with Keith's advice though and try them out first.

Keith. What kind of heads do you have on your 377 if i might ask, and when you talk about a Lunati cam i take that as you were talking about the bigger Comp one, am i right on that one ?

And at last for the fun of it, What kind of horsepower numbers am i looking at here with this engine using the Crower cam and Super Victor intake,, 475-500 honest hp ? (trying to figure out what kind of mph I might see with this combo)

Best Regards
Monzter

[Keith Morganstein]

I think you're mixing up names but that's ok.

The crower cam, super victor combo if "well built" could make 550 - 560 HP @ 7350 RPM, 470 lbs/ft TQ @ 6000 RPM.

Well built means professional attention to detail and tuned properly.

You need a good valve train.

[monzter]

I can see now that i mixed names, sorry about that sir.
Thank's again for your input. This sound like it could get real blast to go down the strip !
I will keep you posted when i start making progress with this project.

Best regards.

[af2]

I think you're mixing up names but that's ok.

The crower cam, super victor combo if "well built" could make 550 - 560 HP @ 7350 RPM, 470 lbs/ft TQ @ 6000 RPM.

Well built means professional attention to detail and tuned properly.

You need a good valve train.

I am sorry, I meant the Crower cam. I run the RHS 235 aluminum heads with Yella Terra Platinum rockers.

Like Keith said you need a good valve train.
Adam

[monzter]

I think my valvetrain is good enough, crane gold rockers 1.6 ratio and stud girdle. Valves are what came in these heads and springs are for solid roller cam, (comp cams cam)
The reason i bought it is because it was recommended for this engine, converter etc... Aside from that it probably needs like 5.14+ gears. As I started to dig further into this sience i see clearly that even though i have these big heads and intake, this camshaft is probably way to big for such small engine like you state above, thus the Crower cam beigin much better choise for my combo. but then again it might be well suited for bigger sbc engine.. On the cam card it says rpm range us 4500-7500 which i highly doubt is correct for 350 engine, you agree with me ?

Best regards.

[1997bird]

Make sure that the valve springs that you have will work with those Crower lobes. You need to look at spring pressure at the installed height, open spring pressure, & spring rate. You need to measure the installed height for each valve and I would suggest to shim them so that you are .070" from coil bind. While your looking at your heads I would also make sure that you have a proper ID spring locator to work with your springs.

[monzter]

I spoke to comp cams the other day and this is the camshaft they recommended the 12-824-14. I also spoke to Ati about this converter and aparantly it's supposed to stall at 5800 rpm. Where would this cam make peak power ? Considering what trap rpm i should aim for.

The springs are for solid roller and are good for. 740" lift. Are the lobes on the crower cam more agressive than on the one from comp?

[dezza]

You could try Overlap of 60.00 degrees and has in Intake Duration of 260.00 degrees. The Exhaust Duration is 275.00 degrees. Your Lobe Separation Angle is 103.75 degrees. The Inlet Cam has an Installed Centerline of 100.00 degrees ATDC. The exhaust cam has an Installed Centerline of 107.50 degrees BTDC.
Best of both cams here you will need race gas

[randy331]

I spoke to comp cams the other day and this is the camshaft they recommended the 12-824-14.

Seriously?? Comp recommended a cam with 276/284 @ .050" for a 355" engine with too big of heads?

That cam is about 25* too big.


Randy