pc325

Hi all, I'm tearing my hair out trying to figure out why my rebuilt engine is destroying camshafts.

I've got a 95 pick-up with a rebuilt 22-RE engine. I bought the head and short block separately (long story) and needed to break in the cam. I used an "assembly lube" that some kid at the local parts place sold me. I installed the cam, set the valve clearance cold, and ran the engine at 2000 rpm steady for 20 minutes. After taking the valve cover off to adjust the valve clearance hot, I notice all of the exhaust rockers and cam lobes were scored. The intake cam lobes and rockers were fine.

I replaced the oil pump when I put in the rebuilt engine. My oil pressure on the dash gauge is about at the halfway point at 2000 rpm, and there seems to be good oiling on all the cam lobes, but the exhaust rocker oilers seemed to take a longer to initially pump oil.

On the rocker arm assembly there is a hole that is a thru hole left when they cross drill the oil passage in center rocker arm support. It is on the exhaust side of the rocker arm assembly. It had a shiny spot in it, and I thought it might have been plugged at one time and the plug was lost. I figured that the oil escaping through this hole might be reducing the amount of oil being pumped onto the exhaust lobes (the oil flowing out of this hole just washes against the valve cover then drains back into the engine - it doesn't seem to lube any part of the valve train).

After weeks of researching, I couldn't find any answer as to whether it's supposed to be plugged or not. I finally just tapped the hole and plugged it with a setscrew, figuring that plugging it couldn't do any damage to the egine.

I also had a suspicion that I was using the wrong lube for the cam, so on recommendation from a friend and also a toyota mechanic, I tried a second cam lubed with a good moly-graphite grease, with the same 2000 rpm for 20 minutes procedure.

Same result - a scored cam and rockers, only on the exhaust side, and out another $250.

Any ideas what might be happening here?

bodo

Did you use new rockers? Got any pics? What did you set the valves at cold?

AH64ID

Yeah did you replace the rockers either time? moly graphite grease seems like the wrong thing to use to me... I just used powerpunch for a good coating on everything and fired it up.... What cam are you using?

pc325

Thanks for the replies.

The first time I used all the old rockers and only the exhaust were scored after the break-in. The second time I replaced the scored exhaust rockers and used the original intakes again - ruined the exhaust again and the intakes are still fine.

The cam is a stock cam from a chain autoparts store - not sure of the one that came with the head, but the second one was a Clevite, and all the replaced rockers were Clevites.

The fact that only the exhaust side cam lobes and rockers are being damaged is what made me think that the hole I talked about in my post must have originally had a plug in it, but since I plugged that hole on the second try and the same thing happened, that kind of blows that theory.

I set the exhaust valve clearance at .012 cold.

I'm going to call the guys at LC engineering tomorrow and see what they have to say.

AH64ID

also try Ted at engnbldr.com

pc325

AH64ID: are you talking about powerpunch 2-cycle oil? If not, can you give me a link to a website where I can find it?

bodo

If you're wiping lobes in 20 min after 2 cams, 2 sets of rockers, and 2 different lubes i doubt lube is your problem. What are you setting your valves at cold? I'll pull the valve cover after the race is over and look for this hole you're talking about because it doesn't ring a bell.

dcg9381

Post a photo of your rocker assembly.. I wonder if you're missing a screw as you mentioned.

You have a problem and it's not assembly lube related.

pc325

I'll try and post a photo tomorrow night.

As I mentioned above I set the exhaust valve clearance at .012" cold.

bodo

Hell yeah my guy won. Now on that rocker assembly the third stantion from the front has a hole in it on the exhaust side that you can see the headbolt through. That is normal atleast on my stock blown up 22re. When you put the rocker assembly on was there any bushings for the rocker stantions on the intake side of the head, the reason I'm asking is my other head some how came up missing a couple of these. Did you pack the oilpump full of vaseline or something similar and then bump the motor with the coilwire off a few rounds? How do the rockers sit on the lobes? When you pull the valvecover and rotate the crank by hand watch the rockers and see if you hear the empty mustard bottle sound when you come to TDC. People tend to feel a feeler gauge a different way a "slight drag" for some may feel different for others. I have a friend who can't set valves without burning them, and I have to go tight because mine rattle. Post back I'll try to help the best I can.

P.S. Do you have a manual and did follow the sequence?

InternetRoadkill

Read thru this thread:

https://www.yotatech.com/forums/f116/22re-timing-chain-installation-97713/

Quick summary:
*Use only new toyota rockers (avoid aftermarket units and never use old rockers on a new cam.)

*Use cams from reputable sources. (Toyota TRD or LC Engineering are good choices.)

* Inspect/replace rocker shafts if they are worn to insure rockers remain square to cam.

* Be sure to set lash correctly.

* Follow installation and break-in directions carefully.

* Be careful using ARP headstuds with the 22RE. They are larger in diameter than the factory headbolts and restrict oil flow into the head somewhat. (The oil passes around the 1st head bolt on the intake side.)

* If you're using an aftermarket head, make sure the alignment insert on the first headbolt has a 13mm hole in it. Mine was a bit undersized which complicated the ARB headbolt problem.

* Don't race the engine on start.

pc325

Bodo,

I called john at LC engineering today and he said the hole in the rocker arm stanchion is normal as well.

He also suggested that maybe I have the wrong valve spring shims and this is causing coil binding. When I pulled the valve cover to take the pics I turned the motor so that a couple of the exhaust valves were wide open and there was plenty of space between spring coils (like .050" or more between the middle coils).

Answers to your questions:

1) there were alignment bushings in the head for the rocker stanchions - none were missing.

2) I didn't pack the oil pump with anything, but did crank it over a few times with plugs out to get the oil to the top of the engine, then quickly smeared some more grease on the cam lobes. Seems to me this should be plenty of lube.

3) on the first cam some of the rockers didn't line up perfectly with the cam lobes, but on the second one all the rockers were lined up fine, i.e. the full surface of the rocker pad was completely on the cam lobe.

4) if by "empty mustard bottle sound" you mean air escaping under compression - yes, I hear it and the engine has good compression on all cylinders.

5) Yes, I use a "slight" drag with the feeler gage. If anything the clearance is set high - more than .012" as opposed to less. The valves are definitely closing all the way, if that's what you're asking.

6) By sequence, do you mean proper headbolt tightening sequence? If so, yes.

I took some pics tonight but they are way too big to post here with the 48.8K limit. Maybe I'll try to retake them on a lower quality setting on my camera and post them later.

AH64ID

Dont lower the quality on your camera, host them for free on photobucket... then we can actually see something in them.. since if you get them to 48kb they are about as big as a postage stamp...

dcg9381

Did you verify oil pressure when cranking or when it started?