Lister Engine Forum

How to / DIY => Engines => Topic started by: Norm Prior on October 29, 2017, 06:59:06 PM

Title: JP2 rebuild
Post by: Norm Prior on October 29, 2017, 06:59:06 PM
Hello. About to start looking at rebuilding a JP2.
As there are JP3 parts available I wondered if the heads off them can be used without issue.
I've not seen any issues raised previously.
Engine will be used on a proper load - not a hobby engine.
Thanks
Title: Re: JP2 rebuild
Post by: AdeV on October 30, 2017, 08:22:58 AM
AIUI, everything above the crankshaft should be interchangeable between JP2 to JP4 (was there a JP6?) models - i.e. rod, piston, rings, barrel, head, injectors, cap & nut.

Fuel pumps will be different, the crank obviously, possibly the flywheel is bigger on the JP3 vs. JP4 (I don't know). Oil pump may be the same, again, I don't know for sure.

Which bits are you looking to replace?
Title: Re: JP2 rebuild
Post by: listard-jp2 on November 01, 2017, 06:22:38 PM
hash=item362410733e:g:0j8AAOSwa3BZ7HPQ
AIUI, everything above the crankshaft should be interchangeable between JP2 to JP4

Would that include the camshaft and manifolds  :laugh:

Oil pump may be the same, again, I don't know for sure.

It is, but the oil pickup and gauze strainer will be different.




As there are JP3 parts available I wondered if the heads off them can be used without issue.

The heads are interchangeable, the only caveat being if the JP3 / JP4 cylinder head has/had the integral water pump fitted, like this one that AdeV recently sold on the maiden bid:
https://www.ebay.co.uk/itm/Lister-JP4-engine-complete-and-running/23253329183

Then to use that cylinder head on a thermosiphon JP2 you will have to carry out some modifications on the internal water passages and fit a blanking plate over the hole left by the water pump to make it work as properly.

I have available some new JP (wearing parts) parts, if your interested send me a PM to discuss in more detail.