Hey guys, I'm wanting to start building an engine for my bird. What I have to work with is a 4-bolt main 355, I'm looking at this bottom end summitracing.com part number WRL-101099, still not sure about heads, cam, or intke, thats what i'm needing help on. also, i'm not sure how much nitrous I wanna run to it. I'm wanting to stay around my budget of 3000 for the engine. I'll probly be buying the heads/intake/carb used. Just need some suggestions on what to get. LMK if you need anymore info

Thanks,
Kyle

 

c'mon guys, can't you give a nitrous newbie some suggestions?

Kyle

 

thats a good set up but i would recomend flat top pistons . it seems to me that nitrous motors like flat tops better. but it also depends on what head cc you have or are getting . heads ,cam, intake depends on the rest of your set up . gears , manual trans , or stall converter, and what you plan for driving habits. still lots of variables

 

well, its prboly gonna have a TH350 tranny, 3000 stall, 4.11 gears, locker, and will be hotrodded most of the time. I'm thinking of somwhere around 150-200 shot BTW.

Kyle

 

I've bought alot of stuff from Frank @ gofaststuff.com ..He gave me a excellent deal on a set of Pro-Topline 235cc heads bare.. if you havent bought anything see if they can give you a pacakge deal for rot assy + topend kit. Also check out Herbert Performance for a cam kit.. I bought their solid roller cam for my tt motor.

 

If you're building the engine specifically to take advantage of Nitrous you might look at the Comp Cams Nitrous HP grinds - they open the exhaust a bunch earlier than in a non power-adder application. They'll give up a bit of power (over a conventional grind) when you're not on the bottle, but take better advantage of the NOS when you're bottle-feeding.

I should add that David Vizard suggests installing these cams a whole 7 - 9 degrees advanced to work best.

 

thanks for all the help guys, I just wanna make sure I get plenty of input before I lay down my money, i'm really thinking about one of those nitrous cams. thanks for the help, more input is appreciated

Kyle

 

The comment about flat top pistons is correct. Nitrous adds a lot of heat to the combustion chamber, and to the top of the piston. Valve reliefs have sorta sharp edges that can retain heat, the raised portion of the piston also has peaks that can do the same thing. In an extreme circumstance these high/low spots can become hot enough to cause pre-ignition. A flat top piston doesn't have those issues.

You'll also want to look for these same charcteristics in the combustion chamber on the head. Sharp points or edges can be potential problems.

You might consider a small CC head and a dished piston. Dished pistons concentrate downward force on the piston, insteed of having the force bounce all over hell in the cylinder to push the piston down. With a small CC head you should still be able to keep the compression ratio above 9.5:1.

You'll also want to look for spark plugs with a smaller electrode. You want the electrode to align with the near edge of the puck, instead of centering over it. The tip of the electrode has to dissapte heat the length of the elctrode, into the plug, and finally into the head. If the electrode is too long, the tip will get hot and cause the same potential detonation I talked about above. Running a cooler heat range plug helps, but does not eliminate the actual problem. In extreme cases I have actually seen guys cut the elctrodes to shorten them up. I haven't ever done that so take it for what it's worth.