LML oil pump conversion info....

[kidturbo]

Nice work.

So basically Melling does the same mod with these pumps that they've done to make HV SBC pumps for past 30yrs. Change the relief spring. Putting a shim in a stock pump should yield similar results.

Now what thickness shim has everyone used to achieve a safe bypass pressure? We didn't mess with the spring on our modified LML pumps. Got me wondering what they actually bypass at..

 

[malibu795]

I exceed that easily with fresh bearings.. at 70-75 psi at 2100 RPM.....

 

[juddski88]

The more I have learned over the past few years about lubrication, bearings, and the like, I have come to agree even more with Rob Codden's method he used in the El Camino of oil supply to the turbo(s) that is: keep it separate and equipment-specific in design. It seems like so much extra work at first to do this, but in the end, it can really save a lot of headache and tail-chasing. The more complicated you make any hydraulic circuit, with several critical sites needing a specific lube rate, the smaller you shrink your margin for error.

just my .02 cents.

P.S. Pertaining to the LML oil pumps, I still prefer them over any other stock-style pumps on the market, and have had great results with them.

 

[S Phinney]

The lml pump is far better than the previous versions. I would only use that if I was using a stock pump. Otherwise I would use a Melling pump.


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[rcr1978]

Here is a couple pics I found of an LML pump apart. On left LML gear, notice the longer shaft.

Also the pump clearance to front cover wasn't main reason we machined housing. Could have just notched the cover. After thinking we had it whipped, the LB7 cam gear we used hit pump on final assembly if I remember correctly. Will post a pic of housing machine area if I can find one.

If you have any more pics or info I want to to try and make one fit. My pan is already machined for a girdle so didn't want to start over with a new front cover/upper pan.

Anyone have any info on the Empire performance pump it's spendy $399 but if it's a machined LML pump I might just save my time cutting and carving to make a new one fit but I'm kinda thinking it's got a new spring in a stock 10 back replacement pump.
Thanks

 

[kidturbo]

Think I know where to find ya a few, by Sunday. The machine shop cost was under a hundo, even cutting the shaft twice..

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[Dozerboy]

Subed


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[kidturbo]

Found a couple pics of the keyed gear mod with shortened shaft we did first. But if I recall correctly, we had to shorten it further to clear the cover.

I'll have to hit Dustin up for photos of the shaved pump case. I just pushed until it fit. He actually did all the grunt work on this one..

 

[kidturbo]

Located these of finished product. Dustin said we cut about 0.190" in the area you can see under reluctor ring. That is on suction side of pump, so shouldn't be an issues with pressure related failure. We used LB7 cam gears with LBZ/LMM reluctor rings. Cam reluctor needed a slight mod on mounting holes I recall.

You can also see the final pump gear and shaft length. And last pic is area of upper oil pan that needs trimmed out.

Hope that helps..

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[rcr1978]

Awesome thanks for the pics :thumb: Did you guys run this engine yet?

 

[malibu795]

Gear sizes on the lbz/lmm oem pumps
12.8-12.9mm thick
51.5mm is biggest OD..
9 teeth
so true OD 52-53mm?

316 pump
OD and teeth count same as LBZ/LMM
Thickness 13.0-13.1mm

Thickness was taken at multiple spots around the gear since they are both worn both near shaft and tooth end of the gear.
Shaft for both was ranged 19.8-19.9mm

 

[kidturbo]

I haven't fired them up yet. Picked up the second engine tonight and grabbed you a few more pictures.

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[rcr1978]

Thanks, did you guys machine the block side of the pump also (back)? Also will the old pickup still bolt up to the LML pump?

 

[rcr1978]

Gear sizes on the lbz/lmm oem pumps
12.8-12.9mm thick
51.5mm is biggest OD..
9 teeth
so true OD 52-53mm?

316 pump
OD and teeth count same as LBZ/LMM
Thickness 13.0-13.1mm

Thickness was taken at multiple spots around the gear since they are both worn both near shaft and tooth end of the gear.
Shaft for both was ranged 19.8-19.9mm

Thanks, the diameter on my pumps was the same @ 52mm some reason I put 26mm on the post

 

[kidturbo]

Thanks, did you guys machine the block side of the pump also (back)? Also will the old pickup still bolt up to the LML pump?

No, block side remains stock to keep gear tooth alignment. GM pushed everthing else out to fit the pump. Pick up tube is now round and much larger on lml than older models.



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[rcr1978]

Stock LB7 pump pops the seat at 55-56 psi
Melling 68psi
Now this is a air check and it is at the point it just cracks off the seat the releif port is not physically open much just enough to leak air, I have no idea what it would be with fluid pressure to actually be open enough to blead off a decent amount off fluid but should be close.

Adding some new found info: LML oil pump press relief valve pops at 88psi and reseats at about 66-68psi.
LML oil pump gears are the same diameter and tooth count as the previous years, the gears are just taller I think it's around .080" will have to check my notes.

Pressure relief in the timing cover of a LB7 starts bleeding air at 30psi= very small amount, it gradually bleeds more the closer to 65psi it gets. The ports are just barely visable at 65 psi, I don't think it bleeds much oil until it hits that.

 

[rcr1978]

Lb7 piston squirters are .063" and open at 25psi, LML are .083" and open at 30psi.

 

[kidturbo]

Nice updates.

Guess I forgot to post some pics of the last LBZ to LML pump swap we did using LML front cover and pans this time.

Since the LML balancer has a different counter weight, we had to cut down an ATI hub to bring everything back in line. But was certainly easier than cutting down a pump again. This method only requires shimming the reluctor ring, and cutting a damper hub to use LBZ accessory mounting locations.

I think the amount of the shim, and what we removed from hub, was 0.185 where it meets the crank gear. In pics below. I'll verify that number and post it. Below you can see diff between an early model and LML damper. However, the visible difference is to the OUTSIDE edge.

As to pump mods above, we double washer shimmed an LML pump this time. That was a bit overkill. She made 90psi at cranking, holds 60psi hot idle now.. But for this application, running synthetic oil, I think it will be fine. Just working that front cover bypass valves a bit.

 

[IOWA LLY]

Are you sure about that? Maybe I’m misunderstanding what your saying?

I put an LML short block in an LLY years ago and we had to spacer out the accessory brackets to make the belt line up. So I’m a little confused about what your saying.


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[kidturbo]

Are you sure about that? Maybe I’m misunderstanding what your saying?

I put an LML short block in an LLY years ago and we had to spacer out the accessory brackets to make the belt line up. So I’m a little confused about what your saying.


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Na your correct.. Guess I worded that wrong on accessories brackets.

The damper thickness difference is actually to the outside edge, belt rib distance to cover side is identical. See pic above ^. Right is LML. We just didn't have any LML brackets to try at the moment...

Our first thought was also to just space the brackets out to line up with ribs on damper in the new location. Same as you did using LML long block. Would work in a complete engine swap. However I noticed a gap between end of crank and end of damper that bothered me. That's when I noticed GM also machined down the center damper area behind counter weight about the difference of new pump thickness.

We actually bolted up an LML damper just to have a look. End of crank snout was even with damper face where washer meets. But as you can see in pics below, distance between the ATI LBZ damper and a factory LML damper on crank snout is huge..

So if using block, crank, and damper from pre-LML, with LML front cover and pump mod, it would also set the belt out a .180 -.200 and require LML brackets or some spacers. Not recommended because it moves the weight out same distance also.

However,, since ya can't uses the LML damper on LMM internals, only decent option is run a matching damper. According to ATI website, the outer assembly was a different part #. So I ordered that one, but once it arrived it, was identical to LBZ unit we had...

Ok, so last option was, machine down the existing hub, which moved the belt ribs back in LBZ lineup. But it also closed that gap between snout to washer, and more importantly, moves the counterweight weight back to factory location from end of crank.

I'll edit that post above.