im shaveing the head on my 1980 pinto and i know the timing has to be adjustid when you shave the head but do you have to buy a special timing pully or can you use the stock one??
i know on th e2.0 you can. the 2.3 is probably similar. in the case of the 2.0 the cam sprocket pointer will not line up properly & the 2.3 is, again similar. those with ACTUAL experience should be able to give you the straight scoop.
in any case if you don't use an adjustable pulley the timing will end up retarded a bit. it will run fine but not as well as it could.
Quote from: srt on August 18, 2009, 06:53:31 PM
in any case if you don't use an adjustable pulley the timing will end up retarded a bit. it will run fine but not as well as it could.
I think thats what he is trying to avoid. Like, is there no welfare/no-buck/hillbilly-engineering way ov getting around this?
I want to do this too, and shave enough to make a difference (.060"?), but the costs add up. To me, there is no point in doing this if the timing is set back.
What does an adjustable set-up cost anyways? Nothing fancy, just enough to fix the problem on an otherwise stock 2.3? Ballpark it if you dont know.
Below are links to several adjustable and one multi key sprocket (not infinetly adjustable). There are probably others.
http://racerwalsh.zoovy.com/product/RWA1443_SQ/Cam_Sprocket_Square_Tooth_2300cc__RWA1443_SQ.html (http://racerwalsh.zoovy.com/product/RWA1443_SQ/Cam_Sprocket_Square_Tooth_2300cc__RWA1443_SQ.html)
http://www.esslingeracing.com/merchant2/merchant.mvc?Screen=PROD&Product_Code=E2188&Category_Code=PUL (http://www.esslingeracing.com/merchant2/merchant.mvc?Screen=PROD&Product_Code=E2188&Category_Code=PUL)
http://www.raceeng.com/p-7469-ul-adj-cam-sprocket2300-sq-tooth.aspx (http://www.raceeng.com/p-7469-ul-adj-cam-sprocket2300-sq-tooth.aspx)
http://www.raceeng.com/p-9875-ul-multi-index-cam-sprocket2300-ea.aspx (http://www.raceeng.com/p-9875-ul-multi-index-cam-sprocket2300-ea.aspx)
I have posted over and over on this subject: retarded cam timing will make your car run like a slug!!! I guess you really need to experience it to understand. If you are not going to correct the cam timing don't bother shaving the head. I have a detailed post in the projects section called "cam timing 101" It's not that hard to do. And with a little work, you can modify your stock gear. Back in my early days of racing I did just that. I took a stock gear and made the key way slot bigger and put a shim in front of it. Not really "adjustable" but it got the timing right. Then I made a few more with different size slots and shims for different degrees of timing. (0 or straight up, 2 degrees, 4 degrees ect) I even made one for my wife's 72 2.0 automatic runabout. The head had been shaved .010" during a valve job. I advanced it 2 degrees from straight up and since it was already 4 degrees retarded that made a total of 6 degrees. It went from a slow boggy take off to spinning the tires on take off. It makes a HUGE difference.
Amen,71pintoracer. You have to try change to thoroughly believe in it. I like the file and shim idea. Way back i did a lot of head scratching and angle finding to have dad broach a new keyway in my stock sprocket to adjust for a 0.60 cut. Not sure we were totally right but it ran way way way better. I do have a used esslinger gear I was holding for a spare, but I'd sell and ship in US for $65. JT
Quote from: 71pintoracer on August 19, 2009, 06:32:09 AM
I have posted over and over on this subject: retarded cam timing will make your car run like a slug!!! I guess you really need to experience it to understand. If you are not going to correct the cam timing don't bother shaving the head. I have a detailed post in the projects section called "cam timing 101" It's not that hard to do. And with a little work, you can modify your stock gear. Back in my early days of racing I did just that. I took a stock gear and made the key way slot bigger and put a shim in front of it. Not really "adjustable" but it got the timing right. Then I made a few more with different size slots and shims for different degrees of timing. (0 or straight up, 2 degrees, 4 degrees ect) I even made one for my wife's 72 2.0 automatic runabout. The head had been shaved .010" during a valve job. I advanced it 2 degrees from straight up and since it was already 4 degrees retarded that made a total of 6 degrees. It went from a slow boggy take off to spinning the tires on take off. It makes a HUGE difference.
71PR has a very good, and valid point. I completely agree....but I will add to it as well...
back in the day we raced "Pro4's". They were a dirt late modle, with a 2.3. We ran a spec .535 cam. Wild little cars. Anyways, we ran adj. cam timing geras from esslinger. We ran 6 degrees retarded.....BUT, thsese motors ran from 6500RPMs at corner exit, to 7700-7900RPMs at turn entry. Obviously this does not apply to your setup - as your otor normally makes power <4500RPMs +/-
High RPMs gain power from retarded cam timing.
Lower RPMs gain power from advanced cam timing.
Heres the theory. Air and fuel make the power in your car....but air(thats carrying the fuel) is SLOW moving (relativly speaking). Your motor (low RPMs) gain power by opening the valve sooner - thus "giving the air more time" to completely fill the combustion chamber. A hi RPM motor will gain from retarded cam timing, because by the time the valve opens, the crank is spinning significatly faster, thus creating a almost "lag time" in when the valve opens to when the air travels into the chamber - creating a scavenging effect. This effect is not present at low RPMs.
So yes, you most certainly want to have advanced cam timing in a lower RPM setup. It will run being retarded after the shaving is complete, but as stated, it will be retarded, and WILL be a pooch.
And on a side note, someone asked then why bother shaving the head. Simply put, this increases the compression ratio. Higher CR means higher HP....in short.
Hope this helped!
Quote from: 71pintoracer on August 19, 2009, 06:32:09 AM
I have posted over and over on this subject: retarded cam timing will make your car run like a slug!!! I guess you really need to experience it to understand....
I HAVE experienced this! Years ago I bought a Cruising wagon w/ 2.3. It was really weak at low rpm's. I pulled out the rubber plug, and the cam belt was one tooth retarded (how many degrees would that be anyway?) After correction, it ran great. I was curious what would happen if I advanced it one tooth, but I never tried it.
One tooth is about 14 degrees, way too much to advance the cam! :D