Lehman SP135 Adjusting engine valves

Got it. Just did not want bad info to stand. Some engines do have the clearances that way, just rare.

My 1986 SABRE manual for the 120hp Dorset:
Intake .015 Exhaust .012

My 1987 LEHMAN manual for the 135hp Dover:
Intake .015 Exhaust .015

All adjustments at operating temp.
(Note: Turbo is .018)

These are both 6cyl 380 cu in engines but the Dover's had closer tolerances and larger ports thus higher hp. I believe Lehman distributed both but put chrome valve covers on the Dover.

I don't believe .003 would make a huge difference in a 40 or 50 year old engine unless you were doing a complete valve job.

-Gary

Set my valves on my 90's to .015. They were at .020-.022. This was probably the first time in 4,000 hrs.

I took Bob Smith's last seminar in October 2015. We set the valves cold and then started up the engine. Bob said it sounded great. He said that he could tell if they were out of adjustment by the sound. He was extremely knowledgeable about the engines.

Being a diesel mechanic for many years, I’ve never retorqued head bolts, nor have I recommended it.
As far as adjusting valves, there are many ways. As long as you are on the inner base circle you are good.

What’s inner base circle?

Thank you for all your replies to my post. However, we seem to have missed the target. My question is - when I removed the rocker cover and I was looking at the valves, I couldn't determine which valve in each cylinder was the intake and which one was the exhaust. I need to know because they require different gaps. Is the valve closest to the front of the engine the intake and does the relationship remain the same for all the rest of the cylinders?

KDA said:

Thank you for all your replies to my post. However, we seem to have missed the target. My question is - when I removed the rocker cover and I was looking at the valves, I couldn't determine which valve in each cylinder was the intake and which one was the exhaust. I need to know because they require different gaps. Is the valve closest to the front of the engine the intake and does the relationship remain the same for all the rest of the cylinders?

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I don’t see another post of yours in this thread so I don’t know what engine you’re referring to since several engines are spoken about in this thread. If you’re talking about a Ford Dover engine (90 and 135 hp) then all valves are to be set at .015” hot or cold according to my manual. In any case for Dorset or Dover engines the valves do NOT repeat the same sequence from front to back.

Ken

Ken, I have a Lehman 120 - I believe it is a Dorset model but don't quote me on that. I have the manual and I believe it has to be hot before you can adjust the valves. The gap is different for intake than for exhaust. My problem is that I don't know how to identify the intake valves from the exhaust valves.

My advice is to download an engine manual. Its states pretty clearly which are which and how to to do the gap adjustments. That way it is all right in front of you. Just did this myself.

KDA said:

Ken, I have a Lehman 120 - I believe it is a Dorset model but don't quote me on that. I have the manual and I believe it has to be hot before you can adjust the valves. The gap is different for intake than for exhaust. My problem is that I don't know how to identify the intake valves from the exhaust valves.

Click to expand...

Got it. My confusion is that this is a 135 thread and I could not find your original post asking for info. And yes, a 120 is a Dorset and the valves are done differently than on the 90/135 Dover engines.

I've just looked through the service and owners manual and there are no illustrations of the head pointing out which valves are which. I can offer 2 suggestions: 1. You might be able to kind of "trace" the valve location with either the exhaust or intake manifold spout between the block and the manifold. The exhaust outlets usually have more burnt looking paint. 2. The exhaust valve spring "caps" have a slight cone upwards toward the center while the intake spring caps are flat across.

If none of that works, you could turn the engine over slowly with a wrench (in normal direction of rotation only) and watch the valves progress.

As a final sanity check, you should not expect the valves to be far out of adjustment. So if you measure some you should see something close to the .015 or .016 for the intake and .012 for exhaust. I *think* you'll find the valves are - starting from the front - IEEIIEEIIEEI. Or some pattern like that.

Ken

PM me your email address. I have the full procedure on how to do it, with diagrams in the factory manual. I just went thru this exact thing myself 3 weeks ago and was just as clueless. Trust me.



Valves are numbered from 1 to 12 from the front of the engine.

1, 3, 6, 7, 10 and 12 are EXHAUST.

2, 4, 5, 8, 9 and 11 at INTAKE.

When 1 and 4 are open, adjust 9 IN and 12 EX.

When 8 and 10 are open, adjust 3 EX and 5 IN.

When 2 and 6 are open, adjust 7 EX and 11 IN.

When 9 ad 12 are open, adjust 1 EX and 4 IN.

When 3 and 5 are open, adjust 8 IN and 10 EX.
When 7 and 11 are open, adjust 2 IN and 6 EX,


Intake is adjusted to .015"
Exhaust is adjusted to .012"

Redhook98, your method is the method described in my manual as well. I've spoken with 2 lehman parts and builders and they use the technique in the manual also. I just adjusted my 135 and when I finished I tried the "overlap" method mentioned by the OP, to check my work. It appeared that my valves needed further tweaking. I decided to trust the manual. If someone has a different experience than me when comparing the two methods I would love to hear about it.