LDS427 Head gasket help

[just weldit]

I blew a head gasket in my truck a while back while hauling my gear home after getting out of the navy. I finally got the heads off and ordered the gaskets over the winter but when I took it to a machine shop they said both heads failed a vacuum test and didn't bother resurfacing them. They have no record of a LDS-427 and insisted that it's a continental TD-427 from a marine application and I should be able to find used parts. I haven't found much information on the TD-427 much less parts. Should I try to find a different machine shop or throw them back on without resurfacing and run it?

 

[JasonS]

The TD-427 only had one head.

 

[just weldit]

That rules out that engine then. It kind of irritated me that the guy at the shop didn't believe me that a LDS-427 even existed.

 

[gimpyrobb]

If you can get pics, I might have a set of heads available. They are off an LDT, but should be similar. I have not seen a 427 in person to know.

 

[just weldit]

I'll try to get pictures tomorrow.

 

[NDT]

If the head does not have grooves cut from the fire rings or hideous cracks around the injector holes, I would run them no prob. Just verify flatness.

 

[gringeltaube]

I do have both model heads here, loose in the shelve, but never bothered to actually compare them to tell any basic differences. I may do that tomorrow.
The LDS427-2 head part No. is #11641632, while the head of the LDT465-1C is #11641633.
The poppet valves have different part numbers also, but the valve seat inserts are the same for both models, so the diameters should also be the same, respectively, for both engines.

G.

 

[just weldit]

Thank y'all for the help. Neither one looks like they have cracks or grooves. After looking up the price of a good straight edge I think it'll be cheaper to take it back to the shop.

 

[aheilmann68]

I have some 427 parts that were tanken from a rebuilt motor if you need. Good luck. The ldt427 I have had 2 heads

 

[brianp454]

Please send the pics and as much info as you have. Data plate on the engine block? Heads?

I'll try to get pictures tomorrow.

 

[WillWagner]

Was the engine running good before the gasket blew? If so, put the heads back on. Early head gaskets were prone to blowing due to the type of gasket used, multi part and non compressable sheet. New gaskets will be modern type with the fire rings and all the gromets made into the gasket and a compressable sheet material. In 25+ years of wrenching on diesel, I have never seen an engine that has multiple head design warp a head, not even a 1710 where the head covers 3 cylinders and is 30 inches long. As stated above somewhere, if no grooves at the fire ring area and no cracks between the valves/injector bore, put it together. Don't take the heads back to the machine shop you used before.

 

[just weldit]

I'm trying to figure out how to get the pictures from my phone to the computer. It was running what I considered to be normal and strong considering it weighed in at 25,000 with trailer and cargo. I had a pyrometer mounted pre-turbo and a manual triggered water injection that helped but I wasn't using it at the time. Shortly after leaving a red light my old trailer brake controller decided to activated on a low setting without me knowing it. I thought it was the small hill I was climbing and even after gearing down it lugged the engine too low and that's when I noticed the steam engine sound. that was 300 miles into the trip. Other than some oil coming out from under the head and it sounding like a steam engine it pulled with just a little less power the last 300 miles home. I added a quart of oil during that last leg of the trip but that didn't seem like a lot of lost oil at the time. I believe it was pressurizing the radiator though because even when the engine was cold on start up it would push some coolant out of the overflow pipe but it never read warmer than normal and after draining the coolant it still looked normal in a clear jug.

 

[just weldit]

 

[just weldit]

Folks say they like pictures so here they are. I've wipe what grime I can off both sides or the engine but can't find the tag. I don't have a plain multi-fuel to compare it to but I doubt they would have put the turbo and new injector pump on from the fire department before getting rid of it. It used to have the side exhaust as well.

 

[NDT]

Weldit, thanks for posting the pictures. That is unmistakably a LDS427 engine and an early 1960's M35A2 (low headlights) that was never used by the military in the 1980's and later. Pictures are no substitute for very careful examination in person, but I would say the head gasket blew because they are prone to do so, not because of warped surfaces.

 

[WillWagner]

Those pics show a very bad overheat. The pic of the block shows blackened and bubbled paint and the close up of the combustion face shows cracks between the valves....That head, at laest, is junk. What do the pistons look like? Take a pic and post it up.

 

[NDT]

Will, I thought the cracks between the valves met serviceability criteria? Not sure where I read that, I think it is from 1960's -34 .

 

[just weldit]

That on the side of the block is probably where I had to use a torch and wax on the frozen nuts.

 

[just weldit]

I'll try to get pictures of the pistons sometime this week. I know some of them have cracks around the cups/ depression. Somebody told me to throw some diesel in the cylinder to check the seal of the rings. Some cylinders held it for most of the day others you could hear a slow dripping after 5-10 minutes. I know this does nothing compared to a compression test but I don't how to perform that test without putting it back together. Without a load behind it would still accelerate pretty good compared to a neighbor's M35A2. With as few miles as I put on it a year I might just run it till it gives up the ghost. As much as I hate the thought there's a good DT466 and 13 speed sitting behind the shop for when that day comes.

 

[WillWagner]

Cracks between valves or valves and injector bores will allow the seat area to expand and then the seat drops out and, there are coolant passages in the head, The cracks will do nothing but get bigger and then start putting coolant in the cylinders and compression into the cooling system. If it were mine, i'd put heads on it, but, the price to repair or replace heads is proably more than the price of a running take out LDT. It looks like the valves have some good ressission too...meaning too much, not a good thing. I thought the machine shop "inspected" these? I'll have to re read your first post.