Low compression

[jim lee]

I've been told that my engine should be coming up on the queue to be worked on late this week. First bit of M37 news I've had in a long time.

-jim lee

[T. Highway]

That's great news, keep us posted.

Bert

[jim lee]

You know, Theodore (The M37's name) lives in a boat building shop. If you'd like some light "build thread" entertainment on another venue. Here's the build log for the couple sailboats we're building as I type. You can see how we do fiberglass.

http://www.leftcoast.biz/iWeb/Left_Coas ... chive.html

-jim lee

[T. Highway]

Jim,

That is some nice looking work you are doing, I had to chuckle when I read about the free sample from the salesman.

Bert

[jim lee]

Talked to the engine guy yesterday. He says that it looks like the engine's never been opened up. At least no signs of it being rebuilt. Very worn out but so far nothing that's not savable. The first pass plan is to bore it 30 over. The crank is going to Seattle to get the #4 journal worked on. Timing chain was ready to skip a tooth. Valves looked fine but the lifters were worn flat. He says he can grind them back to the correct shape without breaking through the hard coating. Same story with the camshaft worn but not too far gone.

Interesting bit was that the engine was OD in the truck. When he hot tanked the parts they came out rusty. I guess it was paint over an old clunker. Hoping to sort parts this weekend for a sand blasting run.

52 M-42, I look at yours and it just makes me jealous. I doubt mine will ever get there, but I do use yours for things like choosing color for different bits. Thanks for posting the pix.

-jim lee

[T. Highway]

Jim Lee,

I wouldn't put the old cam back in, there are NOS ones available from John Bizal at Midwest military. Are you having hardened valve seats installed?

Bert

[RMS]

I wouldn't put the old cam back in

Bert

im with Bert but i would go with a modern grind

the stock cams in flatheads are designed to run on 70 octane! so when you run 89 octane it is rocket fuel in comparison. upping compression and cam really works well.

a couple threads about modding L heads http://www.g741.org/PHPBB/viewtopic.php?f=3&t=5298http://www.g741.org/PHPBB/viewtopic.php?f=3&t=5180

[MSeriesRebuild]

A new camshaft is wise; but be careful, especially of NOS. As we all know they are years old, nobody knows how they have been stored or carefully handled all this time. I figure John does his best to store correctly, but who knows about before he had them. The fact about shaft storage is they will become bent just from laying around; check any new shaft, NOS or otherwise for straightness.

Valve seats are very important, certainly wise to replace both intake and exhaust seats with current production high nickel components. Today's gasoline is certainly not improving in quality. Your machinist should be able to counter bore and install new intake seats; exhaust seats are easily replaceable. Not replacing seats is a decision that has been made and regretted by many. Easy during a rebuild, but a heart breaker not to mention more costly when you have to go back later on after the fact.

[w30bob]

Hi Charles,

I thought most pressed in exhaust valve seats were made of Stellite, which is incredibly hard, whereas Nickel is a soft alloy. For years people claimed certain Oldsmobile 455 blocks were made with "higher nickel content" and were thus better blocks. Turns out thru metallurical analysis it's been determined that Olds never changed the Nickel content.....they changed the Chromium content. Adding nickel would have made the block softer....ie, weaker. Adding Chromium did make the blocks stronger, but also harder to machine. I guess each manufacturer of exhaust seats probably has is own proprietary alloy...but I wouldn't think nickel would be part of the mix.

regards,
bob

[MSeriesRebuild]

High nickel hardened seats have been the go for a good many years now. Stellite valves are available for some applications. Depends on various manufacturers; some offer products for certain applications while others do not. Whatever is a top seller drives the availability.

[jim lee]

All these little metal tubes that are attached to M37 Engines, how are people cleaning them? Do you just hot tank 'em?

Thanks!

-jim lee

[MSeriesRebuild]

All these little metal tubes that are attached to M37 Engines, how are people cleaning them? Do you just hot tank 'em?

Thanks!

-jim lee

Exactly what are you talking about?

[jim lee]

I'm talking about the little metal tubes that are attached to M37 Engines. They are all over the silly thing. Oil lines, vacuum lines, vent lines, etc.

-jim lee

[MSeriesRebuild]

I'm talking about the little metal tubes that are attached to M37 Engines. They are all over the silly thing. Oil lines, vacuum lines, vent lines, etc.

-jim lee

You can clean them up inside and out if you want to go to the trouble. The interior is not easy to get at because of the small ID; for that reason we never reuse them. A couple of other reasons we don't use them is because most are usually deformed and bent to oblivion making it a challenge to make them look decent. We custom bend our own from correctly sized stainless steel tubing. They look nice instead of all out of shape, do not require painting, and never rust inside or out. The nice stainless finish adds a lot to the engine's appearance when fully assembled too. Truthfully, as long as it takes to clean up originals right and paint; we are saving our clients money by replacing in lieu of spending the time to clean properly and paint.

[T. Highway]

Jim Lee,

I would just make new lines, the old ones would never be cleaned well enough to be installed on a rebuilt engine. Not worth the risk.

Bert