Engine identification

[G]

Bought a fully recoed L24 which seems to be a mish-mash of parts and I'm trying to figure out what it might have in it.

 

Block is P30

Head is P90

 

The pistons appear to have a bit of dish to them (damn) and from what I can see through the spark plug holes have a 4 stamped on them (well, the two I can see without turning over the motor do).

 

There seems to be some kind of printing on them as well which is  either RA25 or RA26.

 

Anyone know what these might mean? Would the 4 be 40 thou over?

I've searched and I can't find RA25 on the net.. it's def not KA24.

 

I'm trying to figure out what it has in it and hence calculate the anticipated compression ratio as per the Ozdat calculator.

 

Anyone know what these things might mean? Any sneaky way of identifying the crank without pulling the whole thing apart?

 

 

[d3c0y]

If it's a P30 with dish pistons and a P90 head it's going to be slow unless the P90 has had a heap of meat taken off it. It will have ultralow compression.

 

 

Why dont you put it on an engine stand, tip it up side down and pull the sump off. Then you can see the crank, pull out a piston and check it all out for sure?

[G]

The head has had 12 thou taken off it, so not a huge amount.

 

I've got an F54 sitting on the garage floor as well. I'm tempted to just take the head off and put it on that.

 

Shame to waste a fresh bottom end though.

[d3c0y]

How tired is the L28?

It really depends on what you are after i guess. For me it would be the L28 because it will just make more power.

[G]

I was originally building up an N42/N42 or N42/P90 and this presented itself as a short-term opportunity to get back on the road whilst I build up the warm L28.

 

The L28 I have is N42/N42 with dished pistons. Not sure how it runs..

 

The head on the L28 has not been worked, but neither have the P90's I have (the rebuilt one and one I have under a bench).

 

My plan is to probably unshroud the valves, port match the head and leave it at that.

 

But if the P30+P90 is as slow as a wet week, I need to figure out if I keep the N42/N42 as is or plonk the p90 on it.

 

Hmmmm.. anyone want to buys P90? Lol.

[Riceburner]

RA25 is a Toyota piston I believe. I'm pretty sure Simon had them fitted in the Frankenstein l28, he may be able to shed some more light on it.

[d3c0y]

Everyone wants to buy P90s!

 

 

If you put an N42 on it will have more compression in theory and go better. It's kinda weird to have a P30 with dished pistons too. Maybe someone was using it as a turbo motor?

 

 

If you are building a motor with a P90 you have to take the low compression into account and generally want a piston that will take up a bit of extra area depending on how far you want to take it.

 

 

At the end of the day you need to work it all out and see how much the heads have been planed and what your combustion CCs are and what pistons you are running so you can actually work out what it's going to be. A lot of these parts have been modified over their 30 year plus life span.

 

 

If it's fresh it will get your car running, you just need to figure out what you want short term.

[Agno]

Id take a P90 head off your hands for the right price

[dat2kman]

Whats the going rate for P90's these days?

High/low?

Straight, unmolested.

[Cozza]

Why dont you put it on an engine stand, tip it up side down and pull the sump off. Then you can see the crank, pull out a piston and check it all out for sure?

 

Can you pull a piston out through the bottom end? 

 

[C.A.R.]

Whats the going rate for P90's these days?

High/low?

Straight, unmolested.

$450.00

[NZeder]

$450.00

Really? We don't find many here in NZ - in fact finding a L28 these days takes a bit of leg work/ear bending usually.

[MaygZ]

Can you pull a piston out through the bottom end? 

 

Yes.  In fact if the engine has done a few k's there will likely be a lip around the top of the bore.  This lip can wreck a ring or 2, so going out the lower end is preferred - unless you are going to hone and fit new rings. 

[G]

The engine is actually fully recoed and has never been started.

Just noticed that the sump appears to be on backwards when compared to a standard L24.

Maybe the block came out of a 240k. Were they backwards?

 

Looks like it might be better to part the engine.

Considering it will have a new oil pump, chain and guides, L24 rods etc etc, I'm by default starting to build a box of stroker parts (less the crank and pistons).

 

 

[dat2kman]

The whole cranks needs to be out before a piston will come out, from the bottom end.

The sump sounds like a "front sump" yes off a 240k, 240/260C sedan, maybe a Patrol.

Not all oil pumps get replaced! Pull it apart, check for any faint scoring, if none, it's a freshie.

 

Thank you El Lurcho for the advise on peeninetee, now i know what mine should go for, when i soon retire.

[d3c0y]

Isn't this where we all say it's worth what you can get for it?