Leaking Head Gasket ruined my Schneider 260 cam

[gatemaster]

Leaking head gasket ruined my Schneider 260 cam and rocker arms, fortunately I had an extra set of rockers. Had the head checked for straightness and pressure checked, nothing, all good. I checked the block but it looked straight. I put the head on the block without a head gasket and noticed a little rocking if I pushed down in different places. I really didn't want to take the engine all apart to get the block surfaced. Turns out there was a high spot over one of the head bolt holes at one end. With a new high quality fine tooth file I removed the high spot till no rocking occurred, success. Temperature is stable and car runs cool.
Bought a new cam for $90, now all I need to do is send it in to Schneider for a 278 regrind which is the only cam they have for the 3ac with a 108 lobe offset.

[dlb]

how did the head gasket ruin the cam and rocker arms? i'm guessing oil not getting up to the top of the head, coolant getting there instead, or a mix of both.

[Petros]

I have a procedure where you can resurface the top of the block with the engine in the car in my head gasket repair guild here: https://tercel4wd.com/forums/viewtopic.php?f=7&t=6059

You can also use the same procedure to resurface the head yourself, it actually results in a more flat and smooth surface than a machine shop can do. You might also think about buying a Toyota factory head gasket because I suspect it is much higher quality than any of the aftermarket head gaskets. I suggest you use the procedure I developed for installing the 3ac head gasket, the head gasket is a weak point in the engine design when trying to push it for more hp, you will have trouble with it if you push the engine too far (like I have with my performance rebuild).

The schneider is way too much cam for the 3ac, Synth tried it and also had problems with durability, idle and fuel economy. For less money I suggest the Delta Cam (in Tacoma WA) street performance regrind, I think only about $60 exchange. It is a decent profile and does not affect fuel economy.

[gatemaster]

Petros, it was water. I think it was leaking into a cylinder and steaming up into the valve cover area. I didn't notice any in the oil. Can't say about the cam being too much, it ran really great and the 260f which I had wasn't much over stock but sure did run good. Never had a problem with it until the water leak. my son was driving the car for a period of time and kept putting water in it without telling me until it became a problem with starting issues related to the water leak. by the time I got on the scene the damage was done. Thanks for the head gasket repair link I will check it out, wish I had of come here and asked first. I'll look for the Delta cam unless you have a link.

[Petros]

it does not take much to compromise the head gasket, espcially with a performance built engine. Just one time getting close to the red zone on the temp gauge can weaken it enough that after a number of months it will seep coolant into the combustion chamber. It can run a long time like that, up to a year, but the water seepage gets worse and worse until it is so bad you can not drive it any length without it using up the coolant and overheating. With a stock engine that is never allowed to run hot, it will last a long time, but just once overheating pretty much does it in.

Delta does not have much on their website, but you can email them or call to place an order: http://deltacam.com/

[gatemaster]

Petros, I read your head gasket repair guide. Thank you it was very informative and helpful. I have granite slabs around my house, wish I had read your guide first, it would have been a lot easier. I do want to point out in your guide you didn't remove the 2 locating pins on the block surface. The only high spot on my block was at the rear locating pin location. Probably the reason for previous gasket failures. I would suggest removing both locating pins for surfacing the block. thanks again

[Petros]

Yes, you are correct in that is is better to remove them. I usually leave them in place, without a special tool to remove them you will do permanganate damage to the locating sleeve and they are not reusable. I have found the problem area is between the cylinders, not off in the corner. I would be surprised if a head gasket ever leaked in the corners around these pins. I do check for flat with a steel straight edge, including across these corners. I like getting it within .001 of flat (both head and block), if when I put the straight edge at the corner next to the pin and I have more than .001 clearance under anywhere across the surface, I would than pull the sleeves and flat sand it. If badly warped I have also used a flat file first, than 100 grit, than 200, down to 400 grit wet and dry paper.

Yes, it would be best to remove them, I am not even sure if they are necessary to keep them. At the race shop for Nissan we removed them and never put them back. they just get in the way for cleaning and checking for flat at the next overhaul. I even asked my boss, he said they served no purpose except for production assembly. I think they help keep the head gasket accurately located, but other than that they serve no purposes: it just an assembly assistance.

[gatemaster]

The high spot at the pin lifted the head in a diagonal direction to the opposite corner, which caused the head to rock slightly when on the bare block. I checked the area between the cylinders with a straight edge and feeler gauges and it was flat. But when I checked the same area between the cylinders with feeler gauges with the head on the bare block, there was space and it varied. It leaked between the cylinders, not in the corner. Thanks for the granite idea, I have two pieces that are perfect for doing the block and the head.