l28et 3.1 turbo

[donk]

ok i recently bought an l28et and had it sent to a shop to be rebuilt. piston 4 was cracked and scorched the block so it has to be bored now. this was unexpected and kind of at a loss as of what to do and what i will need now? what all will need to be replaced? thanks for any help.

[blue72]

Okay, does the "What will I need now?" question have anything at all to do with your thread title?

If you are just rebuilding it as a stock sized L28 then the answer to that question is going to be completely different compared to the answer for a 3.1L overbore.

Hint: If it is just one piston bore that is chewed up and you are staying at a 2.8L size I'd have that one hole bored out and sleeved back to the original size. Or just find another L28 block. They're pretty cheap.

Edited September 16, 2010 by blue72

[donk]

when its all said and done i want it to be a 3.1 liter turbo. so im gonna need some kind of bigger pistons, larger fuel pump, injectors, because i'm also wanting to throw a larger turbo on it too.

[cockerstar]

Search, search, search

All of the answers to your questions are at your fingertips.

 

The most common stroker rotating assembly is made up of a V07 crank, 9mm 240z rods, and the appropriate sized pistons from a ka24. This, by far, isn't the most stout combo, but it is one of the most affordable ones.

 

I've given you a start to help you get going in the right direction. Now you just have many hours of reading to do.

There's a wealth of information here, so educate yourself. We're a very supporting community here at HybridZ, but we do place a huge emphasis on learning the fundamentals and answering your own basic questions. When you need help with the specifics, we're here for you

 

 

Also, be sure to review everything here, paying careful attention to #2-5.

[Pyro]

forget the 3.1. not an easy or cheap build. and hard to get the 3.1 liter compression low enough for turbo charging.

 

just rebuild the 2.8.

 

bore the block 1mm and put in new stock pistons (+1mm). The machine shop can handle this easily. This is a small detail. very small.

 

then put the "bigger" turbo on the 2.8.

 

The difference between a 2.8 and 3.1 is about 2 psi of boost. so just add a little more boost to the 2.8 to make the same power.

[cockerstar]

Pyro,

I'm unaware of this issue with the compression ratio on the stroker engines. Can you elaborate?

 

It definitely isn't the cheapest build, $/hp. Going with oversized pistons is definitely a viable and common route during a rebuild. Another option would be sourcing a different longblock that was known to have good compression and oil pressure. There's been a ton of success from members on here with junkyard blocks

 

Also, it's a 12% increase in displacement. The same power can be had from increasing the flow through the engine, but coupled with similar modifications the larger displacement is always going to make more power.

 

 

 

Donk,

Pyro brings up some very good points about the increased cost and work involved with a stroker build. Why exactly do you want to go with a 3.1? What are your power goals for the car and what kind of budget do you have to work with?

Edited September 16, 2010 by cockerstar

[donk]

3.1 liter is just what the mechanic told me he would suggest doing. as far as horsepower i was wanting atleast 350. my budget isnt really big only bout $3000.

[dhartig]

Sorry but $3,000 is probably not going to get you a 3.1 liter engine unless you have great connections and access to a good machine shop. And the 3.1 will be tempermental unless done properly.

 

The good news is there is a ton of good info here on getting 300 Hp out of modifying the standard 2.8 liter. Start searching and see how others have gotten there. I would also suggest checking if your suspension and brakes are 300 Hp rated.

 

Here's a good link to various engine builds.

 

http://www.ozdat.com/ozdatonline/enginedesign/

[sticky280zx]

Please look at this thread, and all you should need is PORTING, more fuel, and maybe a standalone....unless you like all that extra stuff most other turbo guys do...

 

http://forums.hybridz.org/index.php/topic/94800-psi-verses-timing-advanced/

 

 

AKA spend most of your budget on the head, that thing that limits the flow of your turbo engine

[jc052685]

A 280zx turbo I just had my hands on dynod right around 245whp through an auto tranny. This with only a FMIC , 440cc injectors and mega squirt @ 10psi.

 

My car did 324whp 384wtq with mega squirt, 440cc injectors, walbro fuel pump, FMIC and a larger turbo @ 15psi

 

 

Both of these motors were all original L28's. Mine was a 280z l28e. With a cam you can see well over 400whp on the stock L28 with other supporting mods.

[OGB]

Sorry but $3,000 is probably not going to get you a 3.1 liter engine unless you have great connections and access to a good machine shop. And the 3.1 will be tempermental unless done properly.

 

The good news is there is a ton of good info here on getting 300 Hp out of modifying the standard 2.8 liter. Start searching and see how others have gotten there. I would also suggest checking if your suspension and brakes are 300 Hp rated.

 

Here's a good link to various engine builds.

 

http://www.ozdat.com...e/enginedesign/

 

 

If you shop around for the best price on parts and is a hands on person you can build one for well under $2,000. That is about what i spent on my built 3.1. i had the shop do the machining to the block, head, and crank fully balanced. i did all the assembly to the block and porting/assembly to the head and did not skimp on the parts. now im under going a megasquirt conversion and turbo hks surge tank blowing through 45mm oer itb's this is where it gets costly. good luck!

[donk]

my father is a mechanic and we can do all the work short of borimg the block. so price of all the parts is my main concern

[510six]

Okay, does the "What will I need now?" question have anything at all to do with your thread title?

If you are just rebuilding it as a stock sized L28 then the answer to that question is going to be completely different compared to the answer for a 3.1L overbore.

Hint: If it is just one piston bore that is chewed up and you are staying at a 2.8L size I'd have that one hole bored out and sleeved back to the original size. Or just find another L28 block. They're pretty cheap.

 

 

If the rest of the pistons are OK, why not just sleeve one cylinder and source one L28et piston. A bone stock L28et with the right supporting mods is capable of over 300rwh.

[Pyro]

350 hp at the wheels or the crank? You will need a bigger cam if you plan to make 350 at the wheels with boost under 20 psi.

 

cost $1000 to do a "stock" rebuild (with new pistons). add another 1000 for the turbo, wastegate, and the bigger exhaust system, and stronger clutch. then another 1000 for the standalone efi system and intercooler.

 

with a 3K budget I think you need to stay with a stock 2.8 and use a NA cam with a T3/T04e-50 trim turbo with an intercooler, 240mm clutch setup, 3 inch exhaust. Go megasquirt and use 18 psi of boost and make 300hp at the wheels (360hp). and this will most likely cost 4K.

[Pyro]

Pyro,

I'm unaware of this issue with the compression ratio on the stroker engines. Can you elaborate?

 

like putting a 2.8 liter block under a 2.4 liter head, the compression goes up.

 

using KA24DE pistons in a 3.1 liter you will make 8.5:1 cr with a 1mm head gasket and a p90 or p79 head. If you install a 2mm head gasket then the compression with drop to 7.8:1 cr. Still not to the 7.4:1 stock level.

 

Furthermore, using 8.5:1 with a turbo is not good with a stock cam. Ok for low boost (6 -8 psi) but will require a bigger cam to run higher boost.

 

7.8:1 cr isn't that bad but the 2mm head gasket is expensive, kills cylinder head quench effects, and requires the use of an adjustable cam timing gear (more money) do the higher head install.

 

so not worth building a 3.1 for a turbo unless you use custom pistons to select the right dish size (big $) or if you plan to use a big cam like a msa stage 2 or 3 turbo cam (but not street friendly cams).

[Xnke]

Or come out of the 70's and run the 8.5:1 compression...it's not going to hurt you in the least. Or for those who don't mind using dished pistons, Z24 pistons from a 720 pickup already have a 15cc dish in them.