I have a 352 question

[jeffsFE]

I just built a 352 for my 65 ford F100 and it has 9:00.1 compression,stock intake,headers,270 cam and 750 3310 carb. I've only drove it 20 miles and did a compression test and it only had 95lbs in each cylinder and wondered if that was nomal?. Also the vaccum reading was 8lbs,is that because this motor is very new or because of the cam?. The cam is about 224 at .50 so its not to big.

Thanks Jeff

[olddog]

Vacuum and compression both sound low to me. Rings may not be seated yet but I would still expect higher numbers.

If you squirt oil in the cylinders, the rings will seal. So you can check compression then squirt a couple pumps of oil in and recheck. If compression comes up, then you know it is the rings leaking.

Also a compression leak down test will show if there is leakage, but not where. If you use the oil trick and the compression still leaks off then the problem is most likely valves.

Hope that helps you narrow the search.

[olddog]

Are you sure you do not have the valves adjusted too tight? If you do you can burn them, so check it out before continuing to run it.

[jeffsFE]

Thanks for writing back,the motor doesn't smoke at all but a friend thought that the heads might have been milled too much and with stock rockers might be keeping the valves open but the pushrods are spinning on all rockers,so not too tight. Also I found out the dist. was set at 36 dregrees and the initial was at 12,way too high at 48 total. I put the timing at TDC and the rotor was in between #1 and #5 on the cap. Does that mean its one tooth off on the dist. or timing chain?.

[Barry_R]

Sounds to me like you have the timing chain set wrong - probably a tooth off.

[Woodz428]

Did you degree the cam when it was installed?? If not, I would have to wonder about the cam timing/timing gear set up. Non adjustable rockers can create an issue, but the times I've seen it was after a higher rpm run. Usually not at low rpm, although if they are far enough off it could possibly be causing the problem.

[trularin]

Tooth off and may I suggest you set the timing at final only.

Just my $.02 worth.

[jeffsFE]

I'm going to take the timing cover off this weekend and check it then,but when I put it together it was striaght up. Hopefully the new timing tap is correct. I guess if the chain is correct I'll just move the dist. back a tooth. Have you guys ever looked at the cams in these motors before you put in the cam spacer on,it seems like the cam sits back to far the lifters to ride on the cam lubes correctly. Also there was a popping noise from the right side of the motor. Probably because it's not timed right.The sparkplugs are very white at this point,I'm going to have to jet up the carb. It only has #70 in the front bowls.

[ZOERA-SC7XX]

Try to set the dist. rotor to #1 plug wire at TDC before you split the timing cover. That may be your only problem.

[Jac Mac]

Originally Posted by jeffsFE

Have you guys ever looked at the cams in these motors before you put in the cam spacer on,it seems like the cam sits back to far the lifters to ride on the cam lubes correctly.

Cam lobes should NOT be centered in lifter bores, they need to be slightly offset in order to promote lifter rotation. That said there are two types of timing gear sets for FE, one with thrust button that runs via spring against timing cover & later type that utilise a thrust plate in similar fashion to small block fords. Make sureyou have the correct set for your application.

[olddog]

I'm voting with Barry , as the cam being off would explain the low compression and low vacuum.

If you have the tools and know how, you can find where the valves are opening and closing. This will tell you if the timing chain is off a tooth, without pulling it apart. All you need is a degree wheel and dial indicator on a valve.

Quick and dirty check is see where #1 exhaust valve closes then back up until the intake valve closes. TDC should be about half way between these two points.

If the timing at the cam is not off, check how close you are to bottoming out the lifters. If the heads were milled quite a bit and block deck squared up, that sure could bite you.

[jeffsFE]

Well I took the timing cover off today and found out that the timing chain is correct but the new timing pointer I put on is wrong on the balancer. With the timing chain marks striaght up correctly the pointer points at ten degrees after TDC. So when my friend set the timing at 12 degrees initial it was really at 2 degrees. Wow,no wonder it was a dog,lol. I guess that would make one of the cylinders pop a little. Being so far retarted. I took off the timing cover because I was going to check the timing marks and to reinstall the cam spacer that I didn't put in there the first time. It made the cam to far forward and tight on the dist. gear. and didn't want and future problems with gear damage. I did set the dist. at 26 degrees today and with the initial at 12 it should be good at 38 total. Thanks guys,I think I'll start putting it back together tomorrow. These motors are so easy to work on,lol

[olddog]

The compression and vacuum is low and the ignition timing would not affect them. Keep looking. I don't think the time beign 10 deg less than what you thought would cause a cylinder to pop.

[Excaliber]

95 is to low, thats for sure. Should be in the 150 range.

[Barry_R]

Better re-check this too.....

Did you use the split spacer washer behind the cam spocket?

I hope not, because the replacement sprockets all have that spacer washer built right into them.....

[jeffsFE]

I still haven't put the motor back together yet. I just read the last post and wondered about the cam spacer because the cam spocket does set inside the thrust plate about the same as the spacer thicknest. Is this correct??. I wish I know how to send a picture of this washer to you guys,but I'm sure you guys know what it looks like right?. Its just a thick washer that has a 1/4 inch peace cut out of it for the cam pin to stick out into the cam spocket. If thats the case then I will not have to take the gears apart. Let me know guys k.

Jeff from Idaho

[trularin]

Take picture and post it.

[olddog]

I'm not the best at this and always struggle. Open your photo gallery on this site. This site will not accept max resolution picture, so you have to use a photo program to reduce the resolution first. Once you get that done it is fairly easy to copy them. Look in the all Cobra talk area. I think there is a sticky that explains this much better than me.

Once it is in your photo gallery, anyone can see it. There is a way to link it in your post, but it always takes me a half dozen attempts to do it.

http://clubcobra.com/forums/showthread.php?t=83187

[jeffsFE]

Hi again,

I don't know how to load the URL for the picture I have but I've already had a couple of mechanics tell me that the newer cam sprockets have the spacer/washer casted into the sprocket so its not needed. I wonder now if I should of had the heads redone.

[jeffsFE]

Well I don't have a leak down tester but I guess I could take the rocker arm off one side of motor at a time to do a compression test to see if the valves are still open,would that work?