cam installation question

[SS_EURO]

Hey guys whats up,

Question for the pros. I ripped the heads off my 3.1 thinking I blew a head gasket only to find perfect gaskets. So now baffled I rotate the crank and find two valves dont close. Pulled out the lifters and saw the problem was the cam had moved over 1/2 inch or so causing the bearing part of the cam to be holding up each lifter. Does this mean the chain streched too far and I walked the cam as I can't find anything else that holds the cam in the block? I've never seen this kind of crappy design on a car before but it was quick til I walked the cam. Shitty story on how it happened. Ask some time you'll laugh.

Any how any answers would ease my tired mind thanx.

[RacerX11]

RE: cam installation question

Crappy design? It is the same design for cam/lifter retention as just about any other pushrod flat tappet engine out there. The cam lobes are angled slightly, which pushes the cam towards the rear of the block, preventing it from moving forward. Don't use poor design as an excuse for high mileage, poor maintenance, or abuse. Go pull the timing chain and see what the problem is.

Once you get it fixed juice the crap outta it and tell us how it goes.LOL

[SS_EURO]

Well I would juice it if I was going to swap it.

Is this a common thing to happen? I ordered a chain thats made of iron instead of steel and I'm searching for a good cam for everyday use with as much umph as I can get. Any Ideas on other things to help performance?

[geoffinbc]

Go with a stock silent chain. It lasts the longest the stretches the least. Cranes 260 cam is the best street performer. It makes good vacuum and power throught the whole RPM range.

If the cam walked like that something is broken. Did it move forward or back? Check the thrust surface on the block face and the back of the cam gear.

This problem never happens. This is the first I have herd of it

[SS_EURO]

The cam moved 1/2 inch out the belt side of the motor. I really don't understand what has happened inside the block or at least what I should be looking for. The longer the motor is out the more discuraged I get.

[geoffinbc]

Whats the milage on this motor? If the cam was able to walk towards the front then all the tapers on the cam and the convex on the lifters must be worn. Otherwise the cam will always be forced to the back of the block.

There is nothing to be discouraged about. This motor works just like evry Smallblock and Bigblock.

[SS_EURO]

Okay.

I pulled the cam out and actually looked inside for anything.Theres nothing in there that looks to be broken or any weird wearing other then the cam it self. The motor has 269 000 km so it's time it be rebuilt anyhow. I didn't see this thrust plate you guys talk about. On the back of timing gear there are little grooves in it to oil where this rides against the block. That area looks good. I never had a cam out of an engine before so it's all new to me. I've only replaced motors for customers. And sorry about the crappy comment I just get pissed at this whole issue.

[geoffinbc]

There is no thrust plate. Just the surface of the block where it is machined around the cam bearing hole.

Replace theewntire timing set, gears and all when you rebuild.

But in your case I think it is time for 3400 swap. No better time to turn that thing into a screamer.

[SS_EURO]

I'd rather get stupid and do a 350 swap and make this car truley unique if any swap at all.They do it to fieros why not a euro sedan? Plus that thing is probably the heaviest 60* body besides an astro.lol.It's not a matter of how fast but how much. I like tinkering but still have priorities.Thanks for the help none the less. I plan on porting the exhaust and canceling the coolant hoses at the tb. I already scrapped the ac in it. Any other suggestions?