Advance Cam or Not ?

Working on a flat top 532, has C-9 heads with chamber work and some extensive port work,both int.and exh.2.25 and 1.76s valves.1050 dommy,victor 460,solid roller.Engine runs very good,did a compression test,all plugs out and carb wired wideopen,180 to 185 on all 8 . Cam is strait up, could we gain any power by advancing the cam ?, mostly 1/8 mile racing.Thanks for any help, MavMAN

what deg is it set at now?

Yes, you probably can advance it some. Since you have shown the willingness to do a compression check, why don't you advance it a couple of degrees (2 or 3) and then do a compression check again, before you button it all back up. If you can get the compression check to show around 195 - 200 lbs., then it should run better.

Hope this helps,

Charlie Evans

BOSS 429 wrote:what deg is it set at now?

Its never been degreed,we were running it dot to dot .Thanks MavMan

c.evans wrote:Yes, you probably can advance it some. Since you have shown the willingness to do a compression check, why don't you advance it a couple of degrees (2 or 3) and then do a compression check again, before you button it all back up. If you can get the compression check to show around 195 - 200 lbs., then it should run better.

Hope this helps,

Charlie Evans

Thanks Charlie, I have the 9 key way crank sprocket ,to advance I would turn the sprocket counterclock wise,correct?, MavMan

why not try degreeing it in to see were it is now then try and move it a couple degree.most cam comp. like 4 degrees adv.

quick 52 wrote:why not try degreeing it in to see were it is now then try and move it a couple degree.most cam comp. like 4 degrees adv.

I know that would be the best thing to do "quick52", I dont have a degree wheel so im just gonna try advancing it 2 ,check compressing,and then try 4 degrees.I will post the results!. THANKS MAVMAN

you best check valve clearance before you move anything. buy a degree wheel and learn how to use it before you kill it.

The cranking compression is lower than normally seen with that combo , unless the cam is to big for the engine.

And if it is the cam size that has the cranking compression down that low, you may not have much piston to valve clearance to play with.

Cam specs would be good to know for us to help you.

IDT-572 wrote:The cranking compression is lower than normally seen with that combo , unless the cam is to big for the engine.

And if it is the cam size that has the cranking compression down that low, you may not have much piston to valve clearance to play with.

Cam specs would be good to know for us to help you.

780int.727exh.286.294. at .050, 105 atdc, 115 btdc,the piston in this engine has the valve reliefs for both BT or SCJs.and reg.429-460 heads.Thanks "IDT-572",and I hope this helps. MavMan

Looks like a 110 lobe separation cam that has 5* advance ground(or pinned) in to it already.

Bret

Bret Powell wrote:Looks like a 110 lobe separation cam that has 5* advance ground(or pinned) in to it already.

Bret

OK, should I just put it back like it was and leave well enough alone ?,im open for any other suggestions. Thanks MavMan

I think you should put an actual degree wheel on it and see where it currently is. I have seen timing sets over 7 degrees off before. There are no guarantees that the pin holes, and key slots are spot on.

Bret

Bret Powell wrote:I think you should put an actual degree wheel on it and see where it currently is. I have seen timing sets over 7 degrees off before. There are no guarantees that the pin holes, and key slots are spot on.

Bret

OK, so say I degree this baby, and it comes up as the card says to the number,would you leave it strait up and let er eat,or then change for more cylinder pressure and try to get alittle more out of it ? Thank You ,MavMan

I remember years ago reading an article about Ed Iskernandian (spelling) (of Isky cams) and he stated in the article that the way he got the most power out of an engine was to install the cam and check the cylinder pressure then he would advance the cam until the cylinder pressure dropped and then go back to the setting before it dropped. Now I have no idea about radial valve clearance etc. I also have a Ford performance manual that states that you could get more hp and torque out of the SCJ cam by advancing or retarding it either 4 or 8 degrees I'm not sure of the number. I never got the chance to try it in my Torino unfortunately but I would certainly defer to the engine builders on here I am just putting in my 2 cents. Maybe it was that back in the day you could do stuff like that but now today it's not that easy.

I read somewhere that fitting the 1968 to 1970 cam chain and sprockets would alter the cam timing for more power in a 1973 or later engine . Is this fact or fiction? Any mounting alterations or clearances need to be altered? Especially if going for the double roller and billet sprockets.

This is on a bog standard, D3ve a2a headed 1974 460 4 barrel with the (turbo inspired) 8.5 comp ratio and standard cam, sorry for cross posting but sort of related.

Yes the late model timing chains have 8 degree retard in them for emissions. The 1968 -71 chains are strait up. If the timing chain is worn or sloppy(streched), would this not also affect the cam timing? If you don't have piston to valve clearance problems, advancing the cam and rechecking compression seems like a good idea. I have alway read that advancing a cam you will pickup low end performance, at the expense of top end power?