Hi Guys,

I race a 3rd gen in the UK (circuit racing or road course as you guys call it) the only one foolish enough over here to attempt it I believe, I also have a 2nd gen car I race as well.

Any how the championship I originally built the 3rd gen for collapsed and got amalagmated with a slicks and wings formula that made my car uncompetitive so I have been doing some downgrading to enter it into a more stock formula. The major thing I have had to do is change the Edelbrock alloy heads the engine was built with and fit cast iron GM heads and I sourced what I thought was a really nice pair of F5000 camel humps fully worked for a good price.

I rebuilt the engine and within minutes after start up the sump filled with water, to cut a long story short it was leaking through one of the heads valve spring pockets that had obviously been over machined without using a spacer to accept 1.6" springs and had just nicked into the water jacket.

What I need to know are these heads fixable and has anyone successfully done this as it must be a common occurence with this head and they are a great pair of heads that have had big money spent on them apart from that. I have looked at various methods from specialist welding to stitching and even thought about JB weld and gluing a valve spring bucket in place and using a slightly narrower spring. Have any of these methods been successful though is what I need to know as the welding has been costed at $400 alone and the way I look at it there is not much meat for a stitch job in that area.

I have attached a photo that clearly show the problem. Any help much appreciated.

 

Are you shimming the valve springs at all? Is it only that one area, or are there 15 other spots just like that?
If you need to use some spring shims anyway, i'd braze a spring shim in place, making sure to add braze to the area where the hole is.

 

Hi Sonix,

Yes i was thinking along the same lines i can use a lighter and narrower spring no problem, with a shim/locator.

 

You don't have to use a smaller spring if you don't want to. You can simply shim it up a smidge with a .015" shim, and braze that in place.

 

Yeech! I dunno. You might be able to fix it as described, above, but I don't know if I'd ever feel comfortable using that head again.

Why would you ever need springs that big on stock-ish heads? I would think a fresh head but using smaller diameter springs next time might be the way to go. Possibly some of the new style beehive springs. Seems like you can run a really aggressive cam against them without resorting to the usual big diameter, super high pressure springs to control the valvetrain.

 

http://www.eclecticproducts.com/sealall.htm

I would try and repair/fill the hole with this stuff.
Must get the surface oil and antifreeze free. Make sure to push lots of it into the hole to create a plug. Let it harden for a day or two.

I've repaired lots of stuff with this Seal-All stuff.

 

Seriously? I'd use JB weld before I used a one part "thin" adhesive. Brazing it would be a better choice though.