I was told by a friend that I had some burnt valves. I would take his word for it, he builds race engines and Ive seen him determine what the problem is by just hearing the engine. He also told me that I could do a compression test on it. What sould the compression be on a 360. Does anybody know how much it would cost to change the valves and probably the cams on a 360? Is there a good web site to go to to find this stuff?

 

FE engines have been known to burn valves, I assume you're not running on all eight. Broken rings are a possibility as well. It's not so much what the compression is, as that all cylinders should be within 15-20 percent of each other. First, try to isolate which cylinder(s) is/are not firing, and make sure it's not something as simple as bad plugs, wires, or a cracked distributor cap. If all is OK there, pull all the plugs and do a compression test. If you have a cylinder with no compression, pour about a spoonfull of oil or ATF inyo the cylinder and recheck it. If the compression comes up, it's bad/broken rings. If it stays the same, it's a burnt or bent valve. I have seen a bent pushrod cause a cylinder to have no compression. The intake valve couldn't open to allow air into the cylinder. Since there was no air to compress, there was no compression. On the oil trick, the oil forms a temporary seal around the rings, so you get a temporary compression reading. Be careful not to use too much or you could hydraulic a rod, as oil won't compress. As for cost, it all depends on whether you pay someone to do the work, or you do as much as possible yourself. Can you get your racer buddy to help? If you are going to all the work of pulling the heads to replace a valve, if that turns out to be the problem, then you will no doubt want to do a valve job on it. Costs there depend on how much work is needed. Can the valves just be reground, and the bad one(s) replaced. Do the guides need to be replaced, or can they be knurled, which is often just a temporary but cheaper fix, something to consider if you just want to get it going again as cheaply as possible but are thinking about a complete rebuild or replacement/upgrade in the not-too-distant future. It's just hard to say until you get into the engine and see what kind of shape things are in. If it's old and tired, you might want to think about rebuilding or replacing the whole thing, anyway. Is it just a stock driver, and you want to keep it that way, or do you long for more power and want to go to a bigger engine anyway? All things to think about, and maybe more than you wanted to think about right now, anyway. I know that I usually just want to fix the immediate problem and get down the road, but it rarely works out that way. If it's a burnt valve, but the rings are weak and you do a valve job, the resulting higher cylinder pressures can cause you to start burning oil as it is sucked past the rings. I can't say for sure what your compression should be, but I would look for something around 130-150 psi, again what's important is that the lowest cylinder is no more than about 20 percent below the highest. Why do you want to change the cam? (there's only one.) Websites that would be helpful are PAW, Summit, Jegs, among others. Hope this helps, rather than just confuses... Here are some links. -TD

http://www.pawinc.com/
http://www.summitracing.com/
http://www.jegs.com/

 

Nope no confusion here it all made pretty good sense to me. I was going to change the cams to a little more aggressive one but not wild. Thanks for all the info.

 

If you're going to change the cam, then you need to replace the lifters along with it, and you will probably want to replace the timing chain and gears at the same time, they come as a set. Go for the double roller chain, it's a lot better than the stock type. Do you have an auto or a stick tranny? If it's an auto then you can't get too wild on the cam without also replacing the torque converter with one with a higher stall speed. If it's a stick, then it doesn't really matter. I would probably go for the old RV cam, give you a little more bottom end grunt and (maybe) a bit better mileage. It's real easy to pick the wrong cam and make the vehicle unpleasant to drive, so be careful. -TD

 

I have an auto c-6. What is the best way to determine which cam is the best. Like I said before I want something just a little more aggressive than what I have now.

 

OK, then you need something with good idle quality (if you go with the rumpity-rump cam, they usually have a higher idle speed and it will probably come in above the stock converter's stall speed. This makes it a pain to drive, and is hard on the trans). There are so many variables to choosing a cam. How is the truck used? What is the gear ratio? Does it have, or do you plan to install, any other performance equipment, such as carb, intake, headers, ignition? At this point it would be good to get recomendations from other FE owners as to what grinds they have had good luck with. How about it, any other opinions out there? -TD

 

Ratman, visit us down the list at the "FE" engine forum, plenty of folks running strong 360's there..

--Mike