The Stovebolt Site Forums The Shop Area Engine Shop 270 HP for a daily driven 292?

Does anyone know if it's possible to get 270 HP from a 292 using the stock head - no nitrous, no turbo, no supercharger - and not have to resort to using a cam that will give you an extremely lopy idle?

I know that, at a minimum, I'm looking at having to remove the head bolt boss and go with lump ports and larger valves. Probably a 600 cfm 4 barrel and certainly flat top pistons and headers. Would a stock GM HEI suffice for ignition?

What other mods would it take to get to 270 real HP (if it could be done)?

I think it's do-able with a healthy cam, but not with stock ignition. Mallory Unilite combined with MSD-6 box, which will help smooth out the cam. Have you got Santucci's book?

Ftyler,

I think a HEI would do, but to have 270 horses You should use a lot of cam, a lot of compression, headders and a 600cfm carb. But would not call it s street engine. For sure would have a rough idle, but i'd not see need to remove the bolt post yet.

After reading the Power Manual and looking at engine dyno-charts, it would be hard to deliver 270 HP and still be streetable. Small cubic inch engines make hp by running high rpm. One of the engine charts in the book is from Sissell's Automotive. Its a 301 making 450 hp, the charts don't start till 4000 rpm and peak at 7500 rpm.

Go with a turbo charger and have power to spare :p Joe

Yep, my 750 cc bike motor makes 80 horse power. That's at 8000 rpm! It only makes 80 ft-lbs of torque, or something like that.

My 2.5L (That's 152 cubic inches) BMW inline 6 makes 175 HP at 5500 rpm. I would love to have a 333 HP M3 motor to stick in a stovebolt.

You'd be hard pressed to have a naturally aspirated 292 pushing 270 hp to the ground. You'd end up using way too much cam and compression for the street. What are you building the engine for? If it's for street, then build the 292 for torque. That's what they are made for, and good at. If not, then your best bet would be to use a turbo. Even easier (and cheaper) than that would be to use nitrous. Just my thoughts. John

My Father, who has been building inline sixes
since the early 50's, is a big fan of multiple
carbs. According to him it is the single quickest
way to add horses to an inline six. I had a 235
with dual rochesters and fenton headers. Just
those two improvements made it a lot quicker
than stock.

So, for a project like yours dual weber 2 barrels
would probably perform better than one big carb.
2 Webers comes up to 660 cfm, and you can choose
from a number of jet sizes to fine tune it.

I checked the date on your post. I thought it was an old one from before you built your engine?