how can you tell its a l28et?

[woldson]

I've never read that the blocks, rods and crank were any different.

 

Except for possible knock sensor and oil cooler adapter and a sensor that is located in a different postion.

 

Anyhow, the heads can be aurgued abit.

Braap is the best at this information.

Form what I remembered the p79 flows pretty good due the exught transition through those liners, however, what if a liner lets go!???

 

The p90 fairly well thought the square port desing, no liners.

 

 

Conpression is not that high on a na. something like 8 to 1? or 8.5?

Not that high.

 

I'm not the end all for sure, though I have to support Gollams statments, esp conserning quench.

[big-phil]

only turbo block came with knock sensor?

yes only turbo blocks came with the knock sensor.

 

And I did tap one into an N/A block.

http://www.putfile.com/pic/4035322/?action=zoom

http://www.putfile.com/pic/4035325/?action=zoom

[7MGFORCE]

I've never read that the blocks, rods and crank were any different.

 

Except for possible knock sensor and oil cooler adapter and a sensor that is located in a different postion.

 

Anyhow, the heads can be aurgued abit.

Braap is the best at this information.

Form what I remembered the p79 flows pretty good due the exught transition through those liners, however, what if a liner lets go!???

 

The p90 fairly well thought the square port desing, no liners.

 

 

Conpression is not that high on a na. something like 8 to 1? or 8.5?

Not that high.

 

I'm not the end all for sure, though I have to support Gollams statments, esp conserning quench.

 

 

^^ you didnt mention the pistons? wich was what i had originally mentioned. if everything is the same then that would be good new but why dont people run the same amount of boost on the n/a block? maybe i missread what people are saying.

[Vintage]

^^ you didnt mention the pistons? wich was what i had originally mentioned. if everything is the same then that would be good new but why dont people run the same amount of boost on the n/a block? maybe i missread what people are saying.

 

Big-Phil ran 20 PSI on an NA block, I believe, and the early N42 motors also had dished pistons, I think. As far as why you would want a P79 over a P90, they're more common, and thus less expensive. Its also generally acknowledged that it flows about as well as the P90. Now it does have the round exhaust ports, where the factory turbo manifold has square ports, but many people have run it with the turbo manny without issue.

[Gollum]

How many times do I need to repeat myself?

 

NA can take just as much POWER as the turbo block. The reason most NA version of engines can't make as much NA power is due to the compression being too high so the knock becomes unbearable on the engine long before decent power figures are attained. Obviously things like massive intercoolers or meth injection can minimize this, but it's still just working with what you've got.

 

With the L series stock NA compression is a little over 8:1, while the turbo edition is about 7.4:1, or closer to 7.5 with a thinner felpro gasket.

 

The reason people say not to run as much boost is because it won't handle as much boost. Stock turbo bottom can easily take 25psi or so with the sock head, because it'll only be making about 400 fly HP. IF you do some head work and increase the flow, you need to back your max PSI down because you'll be making 400hp at a much lower PSI level.

 

The NA version will reach that magic 400hp mark at a lower PSI, so don't run as high PSI!!! But like I said... The NA bottom end can take just as much POWER as the turbo bottom. Identical crankshaft, block, conecting rods, head bolts, rod bolts, etc. There's some myths running around that the turbo bottoms had slightly different pistom material, but there's no proof I've found, nor that they're any stronger.

 

I reason I mention the people rebuilding with forged pistons is that the ideal piston shape for the P series head is FLAT TOP.... that's my point. Just get a NA engine, and tap it for a knock sensor if you wish. The stock knock sensor isn't that desirable anyways. Get something you can tune frequency with. There's no reason to invest in a turbo version of the engine if you're shooting for the 400hp range imo. Maybe if you just want to put in an engine and increase boost to get to 250-300hp, but that's completely different.

 

And it's worth mentioning again, anything close to 400hp is a needles edge for these engines. On stock EFI you'll be lucky to dyno over 350hp. With any aftermarket EFI you can shoot for 400hp, but don't cry when you've gone through 10 junkyard blocks. The pistons just can't take any detonation at that level. Put in some cheap (but stronger) pistson, even good cast pistons can most likely take way more power than you'll ever get on a stock head.

 

 

Oh, and what head threads are you reading. Sure, the P90 is "the best" in some ways, but it's flow numbers are almost identical to the P79 stock for stock, and some ported P79 numbers stand head to head with ported P90 figured, and that's WITH liners.

 

Either P series head, with flat top pistons is the way I'd go if you're shooting for max power figures with a stock bottom end. I'd also recommend running a meth or ethanol mix to keep the temps down, or do a secondary meth injection. That would make the 400hp figure a bit safer to shoot for.

[7MGFORCE]

How many times do I need to repeat myself?

 

NA can take just as much POWER as the turbo block. The reason most NA version of engines can't make as much NA power is due to the compression being too high so the knock becomes unbearable on the engine long before decent power figures are attained. Obviously things like massive intercoolers or meth injection can minimize this, but it's still just working with what you've got.

 

With the L series stock NA compression is a little over 8:1, while the turbo edition is about 7.4:1, or closer to 7.5 with a thinner felpro gasket.

 

The reason people say not to run as much boost is because it won't handle as much boost. Stock turbo bottom can easily take 25psi or so with the sock head, because it'll only be making about 400 fly HP. IF you do some head work and increase the flow, you need to back your max PSI down because you'll be making 400hp at a much lower PSI level.

 

The NA version will reach that magic 400hp mark at a lower PSI, so don't run as high PSI!!! But like I said... The NA bottom end can take just as much POWER as the turbo bottom. Identical crankshaft, block, conecting rods, head bolts, rod bolts, etc. There's some myths running around that the turbo bottoms had slightly different pistom material, but there's no proof I've found, nor that they're any stronger.

 

I reason I mention the people rebuilding with forged pistons is that the ideal piston shape for the P series head is FLAT TOP.... that's my point. Just get a NA engine, and tap it for a knock sensor if you wish. The stock knock sensor isn't that desirable anyways. Get something you can tune frequency with. There's no reason to invest in a turbo version of the engine if you're shooting for the 400hp range imo. Maybe if you just want to put in an engine and increase boost to get to 250-300hp, but that's completely different.

 

And it's worth mentioning again, anything close to 400hp is a needles edge for these engines. On stock EFI you'll be lucky to dyno over 350hp. With any aftermarket EFI you can shoot for 400hp, but don't cry when you've gone through 10 junkyard blocks. The pistons just can't take any detonation at that level. Put in some cheap (but stronger) pistson, even good cast pistons can most likely take way more power than you'll ever get on a stock head.

 

 

Oh, and what head threads are you reading. Sure, the P90 is "the best" in some ways, but it's flow numbers are almost identical to the P79 stock for stock, and some ported P79 numbers stand head to head with ported P90 figured, and that's WITH liners.

 

Either P series head, with flat top pistons is the way I'd go if you're shooting for max power figures with a stock bottom end. I'd also recommend running a meth or ethanol mix to keep the temps down, or do a secondary meth injection. That would make the 400hp figure a bit safer to shoot for.

 

http://datsunzgarage.com/heads/

 

and i have read somewhere that the piston was made of a weaker material thats why i didnt want to get it. but if its the same cool thanks.

 

and i want to do a stock swap with ms just to see if this engine is something i want. if i like it then i will build one to replace the block. if not then i spend less money. so if it blows at the power level i want then it blows. they seem to be preaty cheap just for the block.

 

 

and im trying to stay away from meth inj. less stuff to add to the car the better. when im set on what engine i want then ill mod accordingly.

[Gollum]

Well if you just want to drop something in and go, then go ahead and get a turbo donor, but make sure to get something that's all original and not missing parts off the engine.

 

If you were planning on custom wiring in an aftermarket EFI then I'd say go with the NA engine with a turbo manifold.

 

But yet, piston limits are identical between the two for any real comparison, and the head flow is almost identical.

 

And regarding the meth, yes I agree simpler is better, that's why I first suggested a meth, or ethanol MIX. Mixing it with gasoline can make for some pretty cheap race fuel that's hard to knock on.

[woldson]

A little ceramic coating dose not hurt etheir.

[7MGFORCE]

Well if you just want to drop something in and go, then go ahead and get a turbo donor, but make sure to get something that's all original and not missing parts off the engine.

 

If you were planning on custom wiring in an aftermarket EFI then I'd say go with the NA engine with a turbo manifold.

 

But yet, piston limits are identical between the two for any real comparison, and the head flow is almost identical.

 

And regarding the meth, yes I agree simpler is better, that's why I first suggested a meth, or ethanol MIX. Mixing it with gasoline can make for some pretty cheap race fuel that's hard to knock on.

 

i thought the stock ecu cant handle 350-400whp?

 

thats why i wanted to go with ms. and if i like how this engine runs then meth inj. is on top of the list

 

thanks for clearing up this issue.

[big-phil]

I thought I had a picture? The turbo piston ring land areas are different from N/A dished pistons. I believe the distance from the top of the piston to the 1st ring is longer on the turbo piston, and each space between each ring is larger than N/A dished pistons.

 

I found what Gollum says to be true. The N/A has too much of a CR. I ran 20 lbs, with timing at about 12deg?? pig rich, and still had detonation. On my true turbo motor now, I can run 16lbs, at 11.5 afr, and 20deg timing. After that the meth starts spaying.

[Gollum]

Yea, NA dish pistons are different than turbo dish pistons to be sure.

 

But again, how much HP where you putting to the wheels at 20PSI on that NA engine? You were flirting with the 400 range iirc, if we're talking fly numbers.

 

And the timing numbers make perfect sense imo. Higher compression is going to naturally burn faster, hence why a lower compression setup can take more timing advance, as it's burn is slower. I'm betting at 20psi you won't be having the same knock issues as with the NA engine, but I also bet on identical setups it wouldn't make as much power either.

 

I still think that if I were doing it myself, I'd just find a NA engine and put a turbo and megasquirt on it and go from there. No point starting anywhere else. Then while getting everything else ready for 400+HP I can build a spare bottom end that can take the power once I get there.

 

At least that's how I'd go about it.