Advance or retard

[oldjohnno]

...To be honest, I've worked with Mike Jones for cams on many successful racing engines. Yes, quite a few wins and championships. Relying on Mikes vast experience in making cams for racing has really paid off for me.

This is - to me - the more reasonable approach. Wouldn't a reputable cam designer/producer be the logical person to ask to spec a cam? If you were feeling sick, you wouldn't go to the doctor and ask for the treatment that was suggested by the majority of respondents on a web forum would you? In light of the doctors training and experience you'd trust his judgement. I imagine this must drive cam grinders nuts, regularly being asked to provide cams that they know are simply not quite ideal for the job.

[88bluestar]

The hydraulic cam I already have, and was in the engine. I'm gauging opinions to see if it makes since to get the solid, which I've used before in a similar engine. I'm trying to determine the least expensive path with this engine. I will be building a better engine in the future, and I have already gotten info from Mike as such, but due to some variables with this stock balanced bottom end I really don't want to spend more than I need to. The solid I speak of is very cheap one that you can get through Summit, and lifters can also be as well. It's a short term solution to get as much as I can out of the engine without overspending. This engine is a bit different as far as valve size, and cid compared to when I used that solid cam before. Have to keep lift low(no more than .505 with 1.5) with respect to valve to piston clearance, pistons have very shallow valve pockets. Another thing I might add is this hyd cam was actually retarded 2 degrees, and was raced on a slightly larger oval track, with a little less gearing.

[88bluestar]

Also have this cam, going to run what I have and save the vortecs for a later build. Should I advance this cam 4 degrees?

IMG_6702.JPG

[MadBill]

The cam card shows the installation at 2° advance. (106° ICL, 110° ECL). Given the frequent dry/slick track conditions you mention, that might be just right but I'd start with 3° more, a 103° ICL. If it hooks up well, try 101 or 102°, if not go to 106°.

[F-BIRD'88]

degree that one and move it to a 102 in c/l.

Set the lash at .016" cold and try it..
Open lash to .022" cold and try it again.
Which is better for that car.
These cams are ment to be played with
to find the sweet spot.

[F-BIRD'88]

k-750's are pure crap.. They snap coila like wildfire..

The cam won't matter... get Isky 235d or lunati 73943
or the summit house label sbc hi perf spring set..
(I believe these are Howards- good stuff too)

Another way is the gmpp blue LS springs and comp converstion retainers.. shim these up for seat and open pressure for racing. 110-130 seat

gmpp puts these on all the sbc high perf crate motors
now. great for .500" .540" sbc dirt solids

Give the K-750's to a competitor you want to hijack

ha ha. sit back and watch ha ha

[88bluestar]

It has comp cams 981-16 valvesprings which I gather are good to .490 lift, this cam shows .498 with 1.5 rockers, I'll be running the stamped type for the time being. I'm keeping the lift as is.

[F-BIRD'88]

Those are a mild hyd cam spring. Not really up to it for racing.
Don't expect much.

[cgarb]

Then halfway though the second race it will munch a valve and we will get a new thread, "Why did my race motor drop a valve?" I mean no offense by this, Why are you asking for advice here if you have your mind made up? You have been given some good advice. I understand using what you have, but if you have the incorrect parts then its all moot point.

[88bluestar]

May still do vortecs. Just not sure how strong the bottom end is in the engine. Weighing extra cost etc.

[cgarb]

Then you have to ask yourself...do I want to win or am I just happy being there going around at the back? I would go look at some of what the winners are running. If they are running vortec heads than that would be a good place to start.

[88bluestar]

Going with vortecs, 235d springs. I have .025 below the deck, .039 head gasket, but shallow piston eyelids, advancing 2 or more degrees I'm curious about piston to valve clearance, mainly one reason that I didn't get the cam Mike recommended, albeit I will definitely get his cam when I build a new engine. This engine is a very low budget deal so I can get going.