southern_chevy

iTrader: (9)

Well I am tossing around the idea of building a 355 with a 150-200 shot on it.
It has been a while since i have messed with a sbc and I am not really sure on what kinda power the parts will hold. It will be mostly a street truck but will see its fair share at the track and will not be a DD. It will have a 5 speed behind it as well.
So I know forged pistons and rods but what will the factory cranks hold?
Also I have been reading up on some of comps nitrous Hp cams and they have seemed to have proven to add hp on the bottle what are yalls thoughts on them. Also I am thinking about using vortec heads as well as a single plain intake with a max rpm around 6500. Also what compression can I run and still use pump gas (max 93 octane) Any tips or ideas are welcome just kinda seeing how much the internals need to be upgraded.

dirt track racer 81

iTrader: (45)

any kind of forged crank and forged h beam rods..eagle preferably.. srp or je forged pistons are good..theres alot better heads out there than vortec heads..im runnin pro top line 50cc heads..on my 355 flat top dirt track motor they are around a 12:1 comp..go to comps site and do a search on nitrous cams..if it were me id get a solid or solid roller cam..not a hydraulic..single plane intake, 750 double pumper, msd ignition would be a plus too for a lot of nitrous, melling oil pump..a new timing gear set..

YenkoST

iTrader: (11)

A cast crank is good for about 500hp NA but nitrous is different...that's a lot of cyl. pressure with a 200 shot. For a 100-150, I say your fine for a little while but 200...you need to go forged....so for your goal of 150-200, you need forged crank.

A nitrous cam will make more power on the bottle than a N/A cam. But the nitrous cam will be down about 20hp N/A vs. a N/A cam. With the vortec heads, need 10:1 and under with the nitrous....the cast iron heads will detonate/knock. I would suggest a 9.5:1 compression on 93 octane using TR6 spark plugs for the nitrous. As far as the cam and 6500 max rpms, in a 355....look at a 218/230 on a 114 lsa. That will peak in a 355 about 5600-5800 rpms with a shift point of 6000-6200.

southern_chevy

iTrader: (9)

I did a lot of research last night and yenko you are right and it being down on power when not on the bottle but there are people seeing huge gains on the bottle with those cams. I was wanting aroung 9.5-10 to 1 compression is what I am going to shoot for. I know that there are a lot better heads then the vortec heads but they are proven heads and are cheap if I was going N/A I could see spending the money but the, also there are a lot of people that run 1.94 intake valves and 1.70 exhaust valves on nitrous and say that it is working great for them as well as being able to run a smaller carb on the bottle being a little better. I might be interested in the solid cam but I need to look into that a little more. But for sure single plain, and somewhere around a 750cfm carb. As far as headers either 1 3/4 or 1 7/8 right? Being nitrous it needs more attention to the exhaust side the intake.

YenkoST

iTrader: (11)

If this is a drag/weekend engine only...1 3/4".....if you are driving it everyday with then 1 5/8". A nitrous cam will make more on the bottle....that's obvious when its a cam for nitrous. Some have seen 30-40hp over a NA cam on the bottle.

I would upgrade the valves to a 1.94/1.6 and a little port and polish on the heads.

The compression you want is in range of pump gas but I would lean toward 9.5:1 a little more than 10:1. Also, TR6 plugs are for a 100 shot. For a 200 shot, you need a 1 step colder plug than the TR6....don't have the number off hand though.

For a carb, a 650cfm is fine.

southern_chevy

iTrader: (9)

ya I got a guy down the road with a set of forged piston he wants to sell that are 9.4 or 9.6 with a 64cc head so I might have to go hit him up for them. and on the 30-40 hp gain that was on a 150-200 shot a think and it said with a 2-300 there were people seeing gains of around 70-90 hp that is one hell of a gain

BadAssChevy327

iTrader: (7)

im running a steel forged crank , 355 , pink rods , je forged 11 to 1 pistons . with world product sportsmen 2 heads , vic jr , demon 750 , msd 6al .

i was told i can saftely run a 250 shot . wih 114 octane . but im lookin for more advice and the guys on here same to know there stuff

southern_chevy

iTrader: (9)

pink rod those use to be like the best rods gm made right? But arent the 96-02 sbc rods better? Anyways I wouldn't think they would hold up with that much force for very long. Jusy my thoughts

southern_chevy

iTrader: (9)

Well I looked up the piston the guy has they are trw forged .030 over and 9.72 to 1 with 64cc heads

YenkoST

iTrader: (11)

Don't go by the listing b/c decking the head and gasket thickness plays a big part in it. Looks like a good piston though.