Using a Tall (Ford crossflow) Block

[gwiz22]

I'm re-bulding my engine using the taller Ford crossflow block. The top has been decked and I asked the machinist to deepen the head bolt holes. Unfortunately, he has gone through on a number. I have two concerns:

1. Will the bolts now become rusted in theri threads and be difficult to remove in the future
2. Will water creep up the threads.

Has anyone had a similar experience using a tall block and can put my mind at rest or should I be worried?

Thanks.

Graham

[mr.vman]

Graham, I don't think cutting deeper threads in the block is needed. I do understand why you would do it, Should be plenty of thread even "decking the block". Many engines have head bolts that go into water jackets. Most common is the small block Chevrolet V8. Use sealant on the threads of the head bolts, should be fine. Steve V.

[Kiwi elan +2]

I shelved my original L block and had a 711 block built for me which was decked a quarter inch. This was done because the L block was due for a refresh and since I drive it every day I wouldn?t be wearing out the original engine. The standard 711 is half inch higher.

More to the point? I used one / eight thick washers under the head bolts to halve the change and ran a tap to the bottom of the existing holes just to make sure things would work OK. Engine runs great but the LOTUS word on the cam cover rubs a little on the under bonnet padding due to the extra quarter inch of height. I would suggest using copper washers under the head bolts to seal as well as a high temp silicon to seal the thread.

[petersracing]

I'm re-bulding my engine using the taller Ford crossflow block. The top has been decked and I asked the machinist to deepen the head bolt holes. Unfortunately, he has gone through on a number. I have two concerns:

1. Will the bolts now become rusted in theri threads and be difficult to remove in the future
2. Will water creep up the threads.

Has anyone had a similar experience using a tall block and can put my mind at rest or should I be worried?

Thanks.

Graham

Replace the bolts with some ARP studs and then use some GMH sealant on the thread in the block (many GMH products have threads into the water jacket)

That way you wont have any possibility of corrosion up the side of the stud in the head.

[tdafforn]

Did the tall block replacement and can confirm that the head bolt holes don't need extending.
Tim

[CBUEB1771]

I would suggest using copper washers under the head bolts to seal as well as a high temp silicon to seal the thread.

Copper washers will continue to crush over time therefore causing the tension on the head studs or bolts to go away and lead to rapid head gasket failure. Hardened steel washers are the normal specification.

[Lotus14S2]

Paint the threads and ends with a sealant like Permatex aircraft gasket goop. It does a good job of protecting the ends of any bolts that penetrate the water jacket. Let it sit a few hours before you thread them in. Either that or just make sure the material is dry before you finish the engine.
There are a number of sealant materials like the Permatex (I don't want to get into a contest as to which is the best), so pick your favorite, but just make sure it is one that adheres well to the metal surface.