[SLVRSHRK]

I have been playing around with static and dynamic compression ration calculators to try and make sure I get my engine build right.

According to CompCams, they grind a 4 degree advance into their cams, but that would put my DCR a bit too high (around 8.3). I've found that by retarding the cam some and installing it only 2 degrees advanced, the DCR settles back to a more livable 8.1.

I see a bunch of timing chain sets on the major supplier sites which have the ability to install at dead-on (which would be 4 advanced with the comp cam I think), or 4 degrees advanced or retarded. Those sets are relatively cheap and common. If you look at them on the Summit site, they state max crank advance at 4 degrees and max cam advance at 2 degrees. Descriptions only state being adjustable in the above increments.

If you can adjust either the cam or the crank offset, shouldn't it be possible to use one of these sets an get the 2 degrees I need?

What am I missing here? Any help is appreciatted.

 

[big2bird]

From my understanding of the sets. The Cloyes or Comp Cams set(Made by Cloyes), can set the cam dead on, 4* advanced, or 4* retarded. I don't believe any combination will get you 2*. You would have to broach anothe keyway to attain this.
I could be wrong, ask my wife.:laughing:

 

[SLVRSHRK]

Comp Cams seems to have adjustment bushings which can be used to get finer adjustments from regular timing chain sets.

Anyone ever used these? Any concerns?

 

[rjent]

Comp Cams seems to have adjustment bushings which can be used to get finer adjustments from regular timing chain sets.

Anyone ever used these? Any concerns?

I have used the Comp (I think they were Comp. ) "bushings" often. I could "dial" in the cam in 1* increments. You basically replace an offset bushing with a hole in it that pressed into the cam pin hole in the cam sprocket! I always liked them :thumbsup:

They provided "bushings" in one degree increments from 1 degree to 4 which gave you a range of 8 degrees.

It make a huge difference in our dirt track cars.

Hope it helps! :thumbsup:

 

[SLVRSHRK]

It does, thanks.

When you say 'pressed,' do you mean with a real hydraulic press, or is this something you could do with simpler equipment?

I have used the Comp (I think they were Comp. ) "bushings" often. I could "dial" in the cam in 1* increments. You basically replace an offset bushing with a hole in it that pressed into the cam pin hole in the cam sprocket! I always liked them :thumbsup:

They provided "bushings" in one degree increments from 1 degree to 4 which gave you a range of 8 degrees.

It make a huge difference in our dirt track cars.

Hope it helps! :thumbsup:

 

[rjent]

It does, thanks.

When you say 'pressed,' do you mean with a real hydraulic press, or is this something you could do with simpler equipment?

No sir, they were a slip fit .. :thumbsup:

We would actually, at times, adjust cam timing based on what track we were going to run.

This has been many moons ago, as I got out of racing in the mid 80's, but I am sure the process is the same. :cheers:

 

[grumpyvette]

ok, Ive built well in excess of 150 engines in the last 37 years, running a small custom engine building concern, and your worrying about something thats of almost no importance at ALL!
2 degrees won,t do much , it may move your torque curve peak,75-100rpm higher and make a slight difference in the calculated dcr but in real world results youll be better off just retarding the cam 4 degrees or selecting a different cam all together.
yes there are bushings available and you can drill and fit them to the timing gear, there are offset crank block wedges, (crank/damper keys)but again its wasted effort in the real world

http://www.romac.com.au/pdf/Std & Offset Crank Info.pdf

http://www.cranecams.com/pdf/16g.pdf

if your truely worried
get this

http://store.summitracing.com/partdetail.asp?part=CLO-9-3100A&autoview=sku

infinitely adjustable up to about 8 degrees in either advance or retard

but you'll need a piston stop, dial indicator, dial indicator base/stand and a good degree wheel to KNOW exactly what your doing and exactly where your indexing the cam in relation to the crank and a good understanding of degreeing in a cam correctly

http://store.summitracing.com/egnsearch.asp?N=700+115+300342&D=300342

use of the dots, as index points will work most of the time in theory, youll be close to correct, if you want things dead on correct you need to take the time to degree it in, the difference can be 5-20hp depending on how lucky you get with tolerances
take the time to read thru the whole thread and sub linked info
its well worth the effort

http://forum.grumpysperformance.com/viewtopic.php?f=52&t=90&p=114#p114

 

[SLVRSHRK]

Thanks for the info, and yes I knew I would need to get the cam degreeing kit. I was planning on degreeing the cam no matter what advance/retard I chose.

I realize that it might not matter much, but since this is my first time at this, I am trying to minimize the thigs that get overlooked. After a while, all those things that don't matter much have a tendency to add up to something.