Autocross Motor Advise

[lpope]

How much horespower do I need in my 66 Nova. Car will get more time on the street but will need to performe well at local autoross events when needed. I have a Detroit speed tubs, 4-link, and front clip installed. I was thinking about going with the RHS block (454) natuarally asperated and using the T56 magnum. I have been told that the 454 can easiy produce 700hp and still be a joy to drive on the street. What are your thoughts and recommendations for a Ls builder who has experiance with autocross/road race, seems most serious builders concentrate on drag.

[Vegas69]

HP doesn't mean much in autocross. My local SCCA proves it time and time again. One of our fastest cars is always an 1980 something Honda Civic. Regardless of course design. Road racing, 0-100-0, drag racing is when hp means something. Autocross is a handling/driver challenge.

[64skylarkls1]

Originally Posted by lpope

How much horespower do I need in my 66 Nova. Car will get more time on the street but will need to performe well at local autoross events when needed. I have a Detroit speed tubs, 4-link, and front clip installed. I was thinking about going with the RHS block (454) natuarally asperated and using the T56 magnum. I have been told that the 454 can easiy produce 700hp and still be a joy to drive on the street. What are your thoughts and recommendations for a Ls builder who has experiance with autocross/road race, seems most serious builders concentrate on drag.

I haven't been around the course as much as many of you but wouldn't the vehicle weight distribution be worse with a big block when thinking of Autocross?

[millertime179]

Originally Posted by 64skylarkls1

I haven't been around the course as much as many of you but wouldn't the vehicle weight distribution be worse with a big block when thinking of Autocross?

Im not a motor guy but i believe the RHS block is an aluminum LS based small block with a taller deck to achieve the bigger displacement. And todd is right, although its fun to have big power it actually makes the drivers job tougher and takes alot more finesse on the small tight autocrosses to get the power to the ground. that motor would be a ton of fun on the roadcourse tho.

[coolwelder62]

Originally Posted by millertime179

Im not a motor guy but i believe the RHS block is an aluminum LS based small block with a taller deck to achieve the bigger displacement. And todd is right, although its fun to have big power it actually makes the drivers job tougher and takes alot more finesse on the small tight autocrosses to get the power to the ground. that motor would be a ton of fun on the roadcourse tho.

You should listen to this kid.There aren't too many faster on an autox track than this guy.

[ccm399]

Not an autocrosser (yet) but I used to be an engine builder....

You want SMOOTH power. Everyone here is correct, big power is not going to make the drivers job any easier especially on a tight course. I nice flat torque curve will make have a larger "sweet spot" so speak.

Not sure that actually helps with your question but an good engine builder (drag or otherwise) should be able to get you an engine that will work for your application. A road course builder might have to take less educated guesses than a drag race engine builder but they both should be able to build you a reliable piece for the autocross. It would be very helpful if you could give them a RPM range you would like the engine to make peal torque, they can work around that for head and cam sizing.

Chris