Buttoning up the motor, a few questions re: quench and degreeing the cam

69 N.O.X. RATT · 04-23-2003, 09:04 PM

Due to the copper head gaskets I am forced to use, I culculate the quench is going to be .043 to .046. From what I know this is a little much especially since my compression is now close to 11 to 1. I know it will probably not run on pump gas, which is not a problem since I have some octane boost mountain motor turned me on to that workes very well. Does any one see any problems with a quench this big ?

I have the Cloyes dual roller timing chain that only allows me to advance or retard the timing +or- 4 crank degrees (2 at the cam) I am thinking I wanted to put the new cam in at 4 degrees advanced, since I can only go 2 am I being to anal about this, any opinions that 2 would be the better choice any way. In my aplication is 2 degrees that big of a deal?

454 + .030
solid roller .652 lift 255 and 262 at .050 on a 112 ground straight up
ported Edelbrock ovals 320 cfm at .650 I/E ratio of 70 %
Victor Jr
Holley HP 1000
10.8 to 1
6 spd 4.40 final drive ratio in 4th

Thanks :chevy

[Modified by 69 N.O.X. RATT, 1:06 AM 4/24/2003]

[Modified by 69 N.O.X. RATT, 1:14 AM 4/24/2003]

88-406 · 04-23-2003, 09:22 PM

I think you'll be fine with that quench. I run mine at .038 but wouldn't have a problem .043-.046!

As for your cam, why not just try it straight up?

KM

CFI-EFI · 04-23-2003, 09:50 PM

Two cam degrees IS 4*. Cam timing is measured in crankshaft degrees. The numbers are expressed as X* BTDC. TDC is a CRANK position.

Piston to head clearence is recommended to be .035"-.040" MINIMUM. The benefits of a close quench dissappear as the clearence approachs or exceeds .060". You're "good to go"! Good luck, and...

RACE ON!!!

[EDIT] PS. With that cam. 11.0:1 should NOT be a problem on pump gas.
"Final ratio in 4th, 4.40:1" ???

[Modified by CFI-EFI, 6:55 PM 4/23/2003]

632C2 · 04-23-2003, 10:36 PM

You have nothing to worry about with a .043 to .046 quench.

I would recommend trying the cam at 2* and 4* retarded as well. I found more power by running my cam 4* retarded. The best way to tell is making a bunch of dyno runs since every combination is different.

427Hotrod · 04-24-2003, 05:15 PM

First off, I wouldn't worry about the quench. You're plenty close enough and much better than most motors out there.

If I'm not mistaken you're using a Comp cam and they routinely grind 4* advance into them at the factory. So "lining up the dots" straight up might well have it already in close to 108/116. Another 2-4* could get you way out of the window!

Are you actually going to degree it in with a wheel and dial indicator or just using the timing chain marks at this point? 99% of the time you'll be OK that way and we know that cam is a known quantity.

I believe last time it was installed at 107* during one build up and then later he tried 109-110 or so. I beleive it picked up a little RWHP when it was retarded, but nothing drastic.

Retarding it will help the top end numbers. It might also help those ported heads flow more at the top end. It will shift your TQ curve a little higher and make a little more HP in the process just becasue it's making more TQ at a higher RPM. Since you're spraying it, usually retarding helps, but I wouldn't get too carried away since it already has a 112 LSA.

I think if it was me, I'd put it in at 110-112 intake centerline and see what happens. I doubt you need much more bottom end!

Steve's luck with retarding his cam a good bit just proves he needs a bigger cam!! Right Steve??? But of course a bigger cam gives up all that streetability, so retarding it is a viable option.

Sounds like you're getting close!!

Remember to watch P/V clearance. As you advance it, the intake valve gets tighter, as you retard it the exhaust does.

JIM

69 N.O.X. RATT · 04-24-2003, 06:00 PM

Jim,

I know that Comp usually grinds +4 into their cams. but Marc custom ordered this one to be ground straight up with no advance.

Since I am a little stuck with my timing chain situation I was thinking of going straight up or use the triangle dot on ther crank gear which is +4 at the crank. I have had a few people say it is +4 at the cam, but I called Cloyes and they said it is + 4 at the crank (+2 at the cam)

I was also thinking straight up because the the chain has 4000 miles on it. I figure it is done stretching.

I was going to line up he dots (either straight up or +4) and then check everthing with a dail indicator at the lifters.

Just so I understand you Jim, you would go straight up or -2 retarded

I am going to check P/V clearance with a clay mock up.

As always thanks :chevy

427Hotrod · 04-24-2003, 07:37 PM

I didn't know if the advance was ground into it or not. I know at one time he had it in at 107 I think. Is this the last cam he had in his motor? I don't remember.

Either way, I would probaby put it in at 110 (2 advanced) or 112 (straight up). I doubt I would retard it much more for your combo. You're going to want to have good recovery when you make gear change and with a stick car you don't have that nice sloppy converter to soak it up. You need GRUNT when it drops back.

JIM