I had my machinist install new valveguides. When I got the motor back together, it started burning major coolant. Sure enough, the oil was milkshaked really bad. Is it worth trying to fix them, or should I just scrap them? If they can be fixed, how reliable would it be? I plan on spraying alot of nitrous.

 

Make them buy you a new set.

 

Unfortunately, it was a long time between when they did the work and when I got the motor buttoned back up. I wouldn't care about salvaging them if they were stock but I have a lot of money into these heads already.

 

Mod: Is there any chance I can post this in Advanced Tech? I haven't had much luck here. Thanks.

 

Really depends upon the crack and the location of it. If thye can get the welding head in there it can be welded. I had a set that was ruined by a blown head gasket, the two center chambers wall between them in the chamber was burnt out, they built em back up and reshaped them to match with a grinder then planed em flat, the heads work fine. I have also seen cracks in the ports fixed with a welder, they have to find the extent of the crack, v and drill it then weld. So you see the location of it is the biggest factor, getting the tools in to do the job.

 

Fixed properly a repaired head is as good as a new. However considering you can buy a set of used heads for about $200 you might think about starting over. Depending on why the motor was rebuilt the head may have already been cracked before taking to the machine shop. Any good shop usually pressure test the heads before rebuild namely if there has been something like a blown head gasket prior to rebuild.

Coolant in the oil is a very bad thing. There has been several articals written about that ruining the bearings. As most coolant contain silica or some flavor of it. Basically what sandpaper is made of. You may stronly consider pulling a main cap or two and a rod cap or 2 for inspection. It may save you some serious money and heartache in the long run.

Just my 2 pennies.

 

The problem is, I have over $2,000 in port work into these heads. They worked find for a long time, but I started having problems after I had new guides put in. Considering the damage is most likely in the areas surrounding the guides, I'm thinking it's going to be a PITA to fix. Agreed?

944,

So are my bearing pretty much junk now? Should I replace the mains, or also the rod bearings. I've been trying to avoid pulling the motor again, but that may be the only option.

Thanks.

 

I would just get replacement heads... u can get a used set for like 200 bux

 

I think it is going to depend on how long you ran your motor, at best it is a crap shoot. Depending on a lot of things it may be worth a look. I thinks this makes for a lot of post that start out with cam change spun my bearings. When in fact the reason they did a cam change because they replaced head gaskets after a blown one and they had ran coolant in the oil for some time. Again this is my opinion and experience. If were me i would replace the bearings and oil pump after coolant being in the oil for more than say 50 miles or so, but that is me. I just hate to do things twice.