I'm building a mildly built motor. It's got a little more cam and a little bump in compression. I'm wondering where I should limit my RPM at. It's a 1970 1.7 with stock valves, springs and pushrods. Thanks all!
Mark D.

there's your answer: stock rpms ...
Andy

Look at the tach. It has a little red band around 5800 rpm. Seriously, I've been having some issues with my 1911 and just got off the phone with HPH and Rich was saying the stock springs were only good for about 5800.

that is why my 2056 would run up past 6K RPMs because I used HD valve springs.

K, thanks guys.
Mark D.

If you are seriously rebuilding your engine and want it to be sturdy, you may want to consider having the heads rebuilt. Stock heads are a weak link in the type 4 chain of reliability.

Less than stock RPM!!
ANY change in camshaft from stock requires better complimentary valvetrain components!

Thats why I only sell cams with ALL the matching, complimentary components.
Skimp here and pick up chunks later.

So what do you recommend for my type of application, Jake? The car will mostly be AXed. Do your dual springs require machining of the head?
Mark D.

The stock springs wont close the valves fast enough, even for a mild life cam...they are just to weak.

Given that fact, the stock heads wont flow worth a crap above 5800...you even loose power after 5k...so its time to shift.
If you want to rev higher than that, you really need heads that are designed to flow more air..
With those heads is the camshaft...they are a matched pair...the cam is designed to the flow of the heads, or visa versa.
The rest of the valve train is designed based upon those two decision points.



Rich

Get a stock distibutor rotor with a built in rev limiter. You will be fine and you can drive the crap out of it and never look at the tach. You will not have time in an autocross.