Kumaro95

As the title says im building my first nitrous motor, actually this is my first rebuild in general so excuse my ignorance. Ill be assembling my bottom end as soon as i get my oil pump and connecting rods this month. The motor has already gone to the machine shop and got new bearings, freeze plugs, bored over .30 and im using the stock crank so that was cleaned up. The bottom end will have Scat pro comp connecting rods (25700716), weisco pistons (Pt003a3). The top end will consist of AI's 200cc Head and Cam kit and the intake will be ported for a 58mm throttle body. Im planning on running a progressive shot off the line and slightly after down the road. The shots will be under 150 for sure. Id like advice and opinions on what you guys think about this so far. I wasnt sure about piston rings for nitrous. the land thickness specs for the pistons are .22 .15 and .08. any particular brand? Also for fuel how big of injectors do i need and what brands do you like? Ill be upgrading the fuel pump also. I appreciate any help.

bowtienut

iTrader: (1)

Are you running a wet kit? If so, then 30 lb SVO injectors are plenty; they'll support any power you'll be able to make with a HR 355 using the stock PCM.
A 150 shot is not a lot of nitrous for 355 ci, no don't have nitrous in your head when choosing the cam. Optimize it for best NA operation with your TC (assuming auto trans?), gearing, and weight, and you'll make the most total power when adding the 150 shot.
I can't help you with pistons and rings; I just run junk stock stuff

Catmaigne

iTrader: (6)

.22" is the top land thickness but you need to know the crown thickness too because they aren't necessarily equal. You also need to take the depth of the valve reliefs into account. Deep reliefs and .22" thickness could result in chunks coming off of your top land because the area will be really thin, especially if you have the more brittle alloy (4032). 2618 alloy I would be less worried about but I think the cheaper Wisecos are 4032 (even though they can be sometimes labeled as "nitrous ready" which seems deceptive).

The Mahles I have for my boosted 355 have a thick .326" top land and .2" crown at the thinnest point. Then again, my pistons are dished but I still wouldn't assume that top land thickness = crown thickness even though you're getting flat tops. It's all up to the manufacturer, you won't know until you ask one of their techs.

Catmaigne

iTrader: (6)

If you're not going crazy with RPM and limiting yourself to a 150 shot then you would be fine with a stock shortblock and a good tune.

Kumaro95

Thanks for the help I ordered the rings. Im at the last few parts for my bottom end. I need my main bearings, rod bearings and main cap bolts. now sense my crank only needed to be polished ill just be ordering the stock clearance. for the rod bearings should the clearance be a little loose cause im spraying or is that only necessary on a big shot? As for the main cap bolts I assume arp is the best way to go.

Kumaro95

I have heard those injectors are the best bang for the buck and are plug and play. So 30lb's should be enough with the intake and heads ported.