LNF Block With LSJ Internals And Head?
 

Will it work? I wrecked my block and need a new one. Have a few options. Just talking with John Powell he has a good LNF block he was going to use with everything else LSJ but ended up just using his old block because it was still good. The LNF is a stronger block. Will this work? Anyone done it or know of any reasons it wouldn't work? Just never heard if it being done but would be a fantastic idea for those that don't need an indistructable block but better than the LSJ block.

technically yes, but there are some small issues. Oil passages in the block for vvt, different parts on the back like the t-stat housing and coolant pipe, but yes it will physically interchange and is stronger.

What's the issue with the oil passages?
Shouldn't b much different if any than ppl using the genII 2.4 block with lsj internals for a 2.1.

Hmmmm. Sounds like more than I want to chew off for my first car engine build haha. I was just curious. John wasn't really sure himself but when he mentioned it, it got the hampster running on the wheel.

Those VVT passages should be blocked off by the gasket and head of your LSJ I would imagine, not a big deal.

I don't know much about the lnf but isn't the hpfp housing built into the block?

I had an lnf head I used for parts, pretty sure it was built into the head.

I think the best thing would be to ask Matt M @ zzp. They always deal with both LNF and LSJ and they know them like the palm of their hand

they are there on the vvt motors and not on the LJS head. As mentioned the gasket may block them, but it isn't designed to. Me personally I would plug them just to be safe.

It's part of the head, no worries. the block castings are pretty much identical aside from the oil passages and them being later model gen 2 with a better internal design.

nope

The gasket takes care of the VVT oil port.

At least it does when running a LSJ head on a LE5 block.

I've got a season and a half on my motor now with no issues, currently running a commetic headgasket.

Should definitely be doable. Hell if the wrist pin height is the same you could just swap the pistons to some non-direct injection ones and call it a day.

Also providing the crank trigger is the same, worst case just run an external one tho.

So I shot ZZP an email asking their opinion if it can be done and Tim got back to me saying this. Interesting.


"GM decided to “improve” the Gen1 block, so they used less aluminum in the Gen2 block to “improve” cooling, but the end result was that the blocks were weaker and more prone to cracking internally. L So we actually prefer the LSJ Gen1 block instead of the Gen2 LNF block. Both have the same upper cylinder weakness without our ZZP girdle but the LNF block cracks internally where you cant see it."

interesting read.....

in

not to side track on the OP thread but there was a thread a while back where someone posted internal shots of the motors comparing them. They were sliced open to compare them. I think it was just a "regular " member and not a shop but I could be mistaken.

Other than that I dont want to quote anyone and get the facts wrong compounding the misinformation.

So back to the drawing board? Go LHU and keep detailed notes :)

If that's the case it is strange to see that the Gen 2 blocks seem to have much less sleeve failures than the Gen 1 blocks.

There are more than a few LNF's north of 400whp on stock sleeves, some even north of 500whp if I'm not mistaken??


Then again, there was a guy with a boosted 2.2 L61 at 518whp on stock sleeves and it was bored 0.040" over.

So anything is possible I guess.

ZZP generally knows their shit.

Lol that would be sick.


Ya I was a little surprised by the reply too. You're right you do hear of less failures with the LNF blocks. But on the other hand like you said ZZP knows their shit. If it was a good route to take ZZP would have probably done it a long time ago is my guess.

i believe sc cars are harder on cylinder walls and upper rings..... thus you get more blown motors on gen 1 blocks coz most are sc..... which in return you see excellent results when do a turbo conversion on the lsj.....

Lol, was just gonna post,

Just waiting for the queens to drop by and turbo>sc, wonder though if immediacy of the sc boost plays a role in popping sleeves.

yes i completely agree and it only makes sense..... turbos ease into boost thus making it easier for the sleeves

Not if you nls

I've seen plenty of LNF'S in the 400WHP+ range as well with no trouble.

ZZP definitely has a point and we all know what the BEST thing to do would be, but on the other hand, if the guy is running a TVS, the LNF block should be just fine.