need advice on flat tappet cam for roadracing HEMI

Posted By: docford

need advice on flat tappet cam for roadracing HEMI - 02/03/14 11:52 PM

we found out that the STX21 cam that came with the used HEMI that I bought is worn beyond specs, so a set of new camshaft with lifters is on the line.

I'm looking for a cam in the 300� adv.duration and .550 lift at the valve range.

Which cam would you recommend ?

The lifter bores are .907. Should I stick with standard .903 lifters ? Which solid flat tappet lifters would you recommend ?

Posted By: AndyF

Re: need advice on flat tappet cam for roadracing HEMI - 02/04/14 12:11 AM

Chase Knight from Crane is a member on here so I'm sure he could give you some suggestions.

Mike Jones would be another cam grinder to chat with. He probably has a handle on road racing Hemi engines.

Posted By: JohnRR

Re: need advice on flat tappet cam for roadracing HEMI - 02/04/14 12:15 AM

Quote:

we found out that the STX21 cam that came with the used HEMI that I bought is worn beyond specs, so a set of new camshaft with lifters is on the line.

I'm looking for a cam in the 300� adv.duration and .550 lift at the valve range.

Which cam would you recommend ?

The lifter bores are .907. Should I stick with standard .903 lifters ? Which solid flat tappet lifters would you recommend ?

What do you mean by " worn beyond specs "

What lifters would you use other than what is available? I don't know of any oversize lifters and Chrysler stopped having those available a LONG time ago .

Posted By: MR_P_BODY

Re: need advice on flat tappet cam for roadracing HEMI - 02/04/14 12:27 AM

With the lifter bores worn that much I would have
them bushed

Posted By: qwkmopardan

Re: need advice on flat tappet cam for roadracing HEMI - 02/04/14 12:52 AM

Call Jim at Racer Brown and get a new STX-21 or have him regrind your old one. If the lifter bores are .907 you should have them bushed.

Racer Brown phone #410-866-7660

Posted By: JohnRR

Re: need advice on flat tappet cam for roadracing HEMI - 02/04/14 09:48 PM

Quote:

With the lifter bores worn that much I would have
them bushed

, buy your lifters and have the bushings sized for the proper clearance, plus enjoy a little power increase from having the correct lifter to cam geometry .

Posted By: jcc

Re: need advice on flat tappet cam for roadracing HEMI - 02/04/14 09:58 PM

Why not just step up to a roller?

Posted By: docford

Re: need advice on flat tappet cam for roadracing HEMI - 02/04/14 10:43 PM

Quote:

Quote:

we found out that the STX21 cam that came with the used HEMI that I bought is worn beyond specs, so a set of new camshaft with lifters is on the line.

I'm looking for a cam in the 300� adv.duration and .550 lift at the valve range.

Which cam would you recommend ?

The lifter bores are .907. Should I stick with standard .903 lifters ? Which solid flat tappet lifters would you recommend ?

the exhaust lobe of the #8 cylinder has 0.060" less lift than the others and all lobes are fully shiny accross their whole surface.

Lifter bores measure at .907 and lifters are .902, so standard .903 lifters or COMP CAMS .904 lifters should work

What do you mean by " worn beyond specs "

What lifters would you use other than what is available? I don't know of any oversize lifters and Chrysler stopped having those available a LONG time ago .

Posted By: docford

Re: need advice on flat tappet cam for roadracing HEMI - 02/04/14 10:45 PM

Quote:

Why not just step up to a roller?

because I'd like to rebuild it like it was back in the day