Need advice, and possibly an engine block for 302 Ford

Jim Rosenthal

Supporter
About 2-3 years ago, the engine in my GT40, built around a 1968 Ford 302 Mexico block, was exposed to a hard freeze, and blew its freeze plugs out. They were replaced, and the cooling system and engine pressure-tested to 22lbs without leakage. However, the engine had not been actually run, and today, following a carburetor rebuild, we fired it up and ran it for a while in the garage. After we shut it down, we noticed a small amount of antifreeze weeping out of what looks like a crack near the front of the block. This is on what would be the passenger's side of the block, but in my car is the (RHD) driver's side. It was a small amount, but it IS coolant. The engine ran fine, once we woke it from its rather sound sleep. It did not overheat or anything of that kind.

I'm trying to figure out what to do next with it. Can this be repaired? The crack is most likely from the water jacket at that front cylinder to the outside.

If it's not advisable to try to repair it, what do I replace the block with? The rotating assembly in this engine is very good quality- all SCAT forged pieces-, the heads are AFR 185s, the engine was built by a very good local shop (Burtonsville Performance Machining in PG County, MD) The engine has MAYBE fifty hours on itd- all those pieces are basically new. If I had to replace the block, I would want to just reuse all the present engine pieces excepting the engine block.

This is not on the engine builder. This isn't their fault, btw. It's mine, for not recalling that I was running distilled water in the car and for forgetting to drain the engine and cooling system.

So- suggestions much appreciated, and JimmyMac, if you have the perfect replacement block for this car, GT40P1149, please DO let me know. I know you have a garage the size of the Royal Albert Hall totally full of GT40 parts..... if you have something you can be persuaded to part with, I'd be ecstatic. That goes for anyone else who might have a suitable item.

Happy holidays, all. And, for what it's worth, she sounded great.
 

Bill Kearley

Supporter
You must know, not a nice pill! A new or good block a must. Have your good parts fitted/machine shop time !!

Good luck with it.
 
Before writing off your block, check out the size of the crack using a crack dye penetrant kit. It could well be possible to get it repaired using 'cold metal stitching'. Good luck.
 

Glenn M

Supporter
I have had very good results, and I mean truly amazing, with laser welding.
It is very intense without the distortion.
I would check that before writing off the block.
 

Jim Rosenthal

Supporter
Thanks to you both. I had not heard of laser welding; I'll try to find out. I am in the Baltimore, MD USA area- if anyone knows of good shops that do the above please let me know.
 

Markus

SPRF40
Lifetime Supporter
Hello Jim,

Laser welding became very common in Germany for those kind of repairs, depending on the exact location of the repair and accessability sometimes possible directly in the vehicle, or at least without teardown of damaged Part.

See same examples

Certainly this company does not work for you - Good luck with finding a local source.....

Markus
 
Laser welding sounds amazing from what I have read and worth investigation. It is possible to simply weld up cracks either with a stick welder and the right rods or even with a MIG. You have to go gently and take your time but it can be done. I would investigate the options before junking the block.
You have two extreme options, latest laser technology or old school repair shop but I would think/hope it is repairable at one or the other
 

Randy V

Admin
Lifetime Supporter
I've been through and worked on hundreds of small block Fords over the years and have never seen a block crack there. I think it is more likely a leaking headgasket and the trail is taking a course down one of the numerous casting marks and fissures in the block. It might also be leaking past a headbolt that has not been properly sealed with liquid thread sealant. Pressure testing and dye will help, but it doesn't always tell the whole story.
 

JimmyMac

Lifetime Supporter
Jim,

Laser welding is a slow process and very expensive and I have used it many times on aluminium.
It would probably be difficult to get a fixed price on this particular repair job as you would have to chase out the crack completely to quantify the costs.

Follow up on Randy's comment before considering taking the engine apart.

Also check the inlet manifold which you are you using with your Webers and have you any bleed lines from the manifold to your header tank to bleed steam or air from the water jacket ?
If you are not venting air or steam properly, there could be enough pressure build up to blow coolant through your gasket seal.

This is our manifold bleed line set up.
Two x 1/8 NPT threaded holes in the back of the manifold where it meets up with the water jacket on the heads.
Fitted with two 1/8 NPT male / male hose adaptors to a bleed line up to the top of the header tank inlet.

Intake mods.jpg
 

Jim Rosenthal

Supporter
Thanks to all. Another forum member is going to look at the engine in the next day or two. I'll mention these issues to him as well; he knows these engines very well. I appreciate all the help a great deal.
 

Jim Rosenthal

Supporter
JimmyMac, there is a bleed line to the header tank, I'm almost certain, but I'm not sure where it originates. I'll ask Ron about that, too.
 

Jim Rosenthal

Supporter
Okay, we've located another 302 Ford block of about the same vintage, not bored out. Ron is picking it up soon. Tomorrow we'll begin getting the old engine out, and figuring out what the problem is. But we think it IS a crack in the block. As I recall, this was a really hard freeze, when it occurred, and it would not surprise me at all to find that it's indeed cracked. More to follow.
 

Jim Rosenthal

Supporter
I will, but I don't know if the machine shop will put them on the 'new' block. Ron found me a 1968 Ford 302 block which we're going to use to rebuild the engine around. We have the ZF transaxle out. If the main caps can't be used on the new block, I'll probably put them up for sale here. But I hope they can be reused.
Thanks for all for sympathy and advice.
 
Hi Jim, hope I'm not rubbing salt in the wounds by asking, what temps resulted in a hard freeze in MD? I know it gets cold there, but I would have thought that with antifreeze etc, you'd have to go below zero to get a hard freeze. Asking because my car sits in an unheated garage in NY.
 
Hi Jim, hope I'm not rubbing salt in the wounds by asking, what temps resulted in a hard freeze in MD? I know it gets cold there, but I would have thought that with antifreeze etc, you'd have to go below zero to get a hard freeze. Asking because my car sits in an unheated garage in NY.
Tom, see this note in Jim's original post where there was not antifreeze:

"This is not on the engine builder. This isn't their fault, btw. It's mine, for not recalling that I was running distilled water in the car and for forgetting to drain the engine and cooling system."
 

Jim Rosenthal

Supporter
Progress: old engine out of the car, and torn down to the short block. The crack in the outside of the water jacket goes all the way up to and includes the deck surface- so this block isn't salvageable. Ironically, the casting codes seem to indicate that the 302 block around which we will rebuild the car's engine is actually older than the one that cracked.

All the engine's internals appear to be fine, all the accessories intact. The new old block goes to the machine shop soon, along with a sample piston, the crankshaft, the cam, etc. Hope to be running again in a couple of months, in time for nice weather around here.
 
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