I just purchased an L28 it’s complete except it’s missing 1 of the 7 main caps. Where can I go to purchase a new set?

 

 

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I know of nowhere to buy new caps. You'll have to find a donor and then line bore the engine. Caps are machined for one location in one motor only

If I were in the middle of the outback and needed to get to the hospital, I might try swapping the cap from one motor to another just to save a life. But I would never expect it to last.

And I certainly would never try that on cap #4 or the rear cap #7.

So unless the guy you bought the motor from turns up the missing cap, it sounds like you bought a paperweight.

I have come across this company https://billetspeedworks.com (formally known as Pro Gram Engineering) this looks promising, does anyone know of any other companies?


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Why not just source a cap and line bore? Its way cheaper than those caps

Why not just source a cap and line bore? Its way cheaper than those caps

Can I get any L28 main caps, and have them line bored to fit?


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That depends. I believe there are 3 unique caps in the L28. The middle cap, the rear cap and the other common caps. You need to know which one is missing and then have it line bored with all the caps installed

Well I'm not sure what everyone here is talking about when they suggest line-boring, but where I come from, it would mean putting all the caps into place at spec torque, and then running a cutter through to remove material thereby making sure all the journals all perfectly in-line and the same size.

But my question is... What then? You'll need larger bearings with more meat on the outside to make up for the material you took off. You got a source for that?

You can get "oversized bearings" with more meat on them on the INSIDE for when the crank is ground, but to find bearings with more meat on the OUTSIDE that were designed to fit into a larger block bore? I mean... I've never looked. Is that a thing?

I suppose you might get lucky and only have to take material off the new cap. maybe you could weld the new cap in prep. 

But I'd think just buying a complete l28 block would be easier and cheaper. 

Here, when they line bore, they shave all of the caps. Torque them down and rebore all the way through for a concentric std bore

10 hours ago, jonbill said:

But I'd think just buying a complete l28 block would be easier and cheaper. 

I think that the caps are considered part of the engine block.  Not shown as available as separate pieces.  A guy could probably go to a wrecking yard and find one then have a machinist make it work.  But, it's still going to come from a used engine.  

I'd have the guy search his garage for that cap.

http://www.carpartsmanual.com/datsun/Z-1969-1978/engine-280z/cylinder-block

 

For the record though, you can buy main caps for a Chevy small block from numerous places.

You might call somebody like Datsun Spirit or Arizona Z Car, if you decide to try to save the block.  They build engines.  Might even have some used ones.

https://www.jegs.com/i/Speedmaster/746/PCE289.1002/10002/-1?gclid=Cj0KCQjw9_mDBhCGARIsAN3PaFNMd6jy7Ofu06P4cJsdCpPw58lu4UozC605W25FcJdrOXT8lkmMhT4aAjA4EALw_wcB

https://datsunspirit.com/

http://arizonazcar.com/