Need advice with 350 four bolt main
 

I am just about finished with my 76 camaro and will be starting on my 350 block that I have. I am needing advice on what is the best set up for building this engine. I have a budget of around $4000. Listed below for the 3/8 mile track is the enging spec rules. I thank you for any and all help.

ENGINES
1. 362 cubic inch MAXIMUM.
2. Stock production case iron heads only. No porting or polishing.
3. Stock rocker arms only. No roller tip or roller rocker arms.
4. Screw-in studs and guide plates allowed.
5. After market camshafts are allowed. No rollers.
6. Must pull 15 inches of vacuum at 1000 RPM’s. Vacuum to be pulled
from base of carburetor or intake. Top three (3) cars will be checked
after Feature Race. 12 Volt hookup for track tack required. Al engines
must be turned off after vacuum test.
7. Flat top or dished pistons only. Two valve relief piston allowed.
8. Stock rods. (Example: Chevy 350 5.7 only. After market rod bolts
okay).
9. Stock aftermarket crank OK (No cutting).
10. Stock HEI or point distributor. No supercoils or magnetos or MSD.
11. Cast iron intake only. 2 or 4 barrel okay. No polishing!
12. Carburetor’s spacer NOT EXCEDDING 2 inch IN HEIGHT.
13. Mechanical fuel pump in stock location. Stock manual fuel pump. No
electric or belt driven pumps.
14. Headers or exhaust manifolds allowed. No 180 degree headers.
15. Carburetor can be NO larger than Holley 500 CFM 2 barrel and must
pass inspection from top side with gauge. (Must be stock venture 1 3/8
inch). Choke horn may be removed.

is this a corvette motor?,,,,,,,,,J/K looks like the rules will dictate the motor.

I'd go for compression and lots of it. jmo

ok 1st off i would go with vortec heads, cus they flow really good without porting, i would also look at some new valve springs with a lil more seat pressure, and a comp flat tappet, only because u can call comp and theyl tell u witch cam will give u the most power, only catch is that with vortecs if u run bigger than a 480 lift cam u have to mill the spring pockets, if u do that it will give u about a 530 max lift, different springs will also allow for more lift flat tops would be good,and arp rod bolts are must if ur makin anykind of reall power, i would also go with arp head and main bolts or studs,
hope this helps

From what i've heard
 

I think around my parts a lot of guys angle mill the heads to say 18 degree or possibly 15 degree, don't know anything about it but they tell me it makes a lot more power. I think you can sneek in Comp rockers that look stock but are a lot stronger maybe 1.6 ratio? Also don't quote me on this but i believe Scat might sell a stock appearing rod that's much stronger than stock think around 250.00.

Good Luck!

It is not a corvett motor. It came out of a 70's truck I think. But it is a four bolt main. I am new at all this engine building stuff. Will I need to boer the engine out 40? Thank you all for your help.

SAYING IT CAME FROM A CORVETTE ADDS 25-30 HP

and saying ti has a 3/4 cam in it adds another 10-15hp on top of that

Thanks. I didnt know that. Wished I had one, but I guess that she will have to do. :wink:

LOOKING AT THE REQUIREMENT IN THIS CLASS, A STOCK 350 & WITH THE VACUUM REQUIRMENT A MILD CAM IS ABOUT ALL YOU CAN DO.

Bore it to the max cubes, flat tops, headers, a 2 inch spacer, 500 CFM Holley, vortecs heads over regular production heads as they do flow much better but I dont know if they make a cast iron vortec manifold so you may be stuck with the other heads, cam change for sure, probably somewhere around a 268 high energy.


Ever heard of abrassive media porting? Looks just like a factor casting when done right, I've heard that it works wonders on heads and manifolds in these stock motor classes - Shhhh > anciet chinese secret.

Cp

Shhhh > anciet chinese secret.
:lol: :lol: :lol: That was to funny.

It's too bad Smokey Yunick is gone. He could'a got 700 horse out of this motor.

I was told to have the valves grinded to allow better air flow. Is this true?

Most aftermarket valves will have swirl finish, undercut stems. For a little more, backcut the head of the valves.
I am unsure what valve jobs are legal, but a five angle, three angle or radius job are all options to consider.


Dave

I hate to sound silly, but what and how is a back cut done. Does it allow more air flow. I know that the rules doesnt say anything about valves so i assume that it legal. Thanks

a backcut is a different angle (in your case 30*) cut from the normal seat angle ( IYC prob 45*) It goes from very near the edge of the seat inwards till it goes into nothing into the head of the valve( hope this is clear) It is done on a valve refacer. It will allow more airflow as will paying very careful attention to the valveseat area specifically as Dave has stated.I would also add since valves are "free" in these specifications you may consider thin stem valves also.

Thank you. Looks like the information that I need is getting good.

I also do a 25 degree top cut on the head of the valves. But do not compromise the thickness of the valve (leave margin at .030 to .060).
A top cut will create a tighter cone shaped air flow areound the circumference of the valve head, especially important on the exhaust valve.

Dave