Boring/Stroking question

[Drftn280zxt]

alright I've got a couple of questions/ ideas that I couldn't seem to answer by searching.

 

#1 Can you stroke and bore an engine?

If so can you bore a L28et to 3.1L and then stroke it?

Would stroking only require longer rods or a new crankshaft as well?

#2 If you bored and stroked the motor, and ran twin T03/T04 turbos would you get good horsepower? (with intercooling,adjustable wastegates,electronic boost control, and dual blow-off valves both recirculated through the intake)

Would there be a lot of lag?

#3 If all of the above was done along with head work on a P90 along with uprgraded internals, what kind of horsepower would be possible roughly

Could it be run on pump gas (91 premium octane)? Street Legal?If I could do this someday I think it would make for an awesome daily driver.

[Guest tejas74260]

im not sure it would be too safe bore-ing a f54 block more than 90 mm, and with the stock stroke (i believe its 79mm), you can only get close to 3 liters. rebello racing makes a 3.2L engine, and im sure you can just have a long block built, im pretty sure they know their stuff when it comes to working with l series heads (dont send it to a chevy guy ) anyway, im sure people have more to add than i did, and correct anything i might have had wrong. as far as turbos, that's far beyond my expertise (just that i know most people go with a large single turbo set up) good luck

Mark

[Mack]

#1 "Can you stroke and bore an engine?"

 

yes.

 

"If so can you bore a L28et to 3.1L and then stroke it?"

 

you cannot bore an L28ET to a 3.1. To get the 3.1L of displacement you have to bore AND stroke the L28, not JUST bore or stroke it.

 

"Would stroking only require longer rods or a new crankshaft as well?"

 

rod length has nothing to do with stroking a motor, other than the fact that if you use the same pistons, you will need shorter rods to make sure the pistons dont stick up above the deck of the block. Stroking a motor involves making the throw (stroke) of the crankshaft longer. Stock L28ET crankshaft have a stroke of 79mm, where as LD28 crankshafts (the deisel crankshaft) has a stroke of 83mm.

 

 

#2 "If you bored and stroked the motor, and ran twin T03/T04 turbos would you get good horsepower? (with intercooling,adjustable wastegates,electronic boost control, and dual blow-off valves both recirculated through the intake)"

 

yes, you would ge tgood horsepower, if everything were set up right. You'd probably want to consider running a standalone fuel management system with some big injectors tho. also, porting the P90 head and a custom intake manifold would be almost REQUIRD at that point. as well as a custom turbo exhaust header.

 

"Would there be a lot of lag?"

 

Yes, I would think t03/t04's would be a little much, perhaps just go with some BIG T28's. they should provide ample HP and not have as much lag.

 

#3 "If all of the above was done along with head work on a P90 along with uprgraded internals, what kind of horsepower would be possible roughly? Could it be run on pump gas (91 premium octane)? Street Legal?If I could do this someday I think it would make for an awesome daily driver."

 

it all depends. the electramotive team that racced a 280zx during the 1980's was running about 600rwhp out of a 2.8L motor. no one has been able to duplicate those results, however, there is a guy that is running about 475rwhp with a single turbo on a 280zx (JeffP) with a lot of money, the sky is the limit. would it be street legal? depends on how you set it up, it could be, and it could not be. Run on 91 octane? if you had a low boost setting, but making 600rwhp on an L series motor with 91 octane would be a feat to acomplish, for sure!

 

McAdam

[jeffp]

First off you NEVER want to bore a L28 block to get 3.1 liter, in fact you will bore through the cylinder walls trying to get a bore big enough with a stock crank to make 3.1 liters.

You will need an LD 28 crank (83mm stroke) and 89mm pistons to get to 3.1 liter. BUT, I dont recommend boring a turbo engine to 89mm as the cylinder walls become to thin in my opinion. Bore the block to 88mm and build a 3.0 liter. The displacement and hp difference is not worth the possible results with the turbo engine.

A good turbo will get you 20psi of spool @ 3K rpms, that is excellent, so if you want to call that lag ok, but it is very usable power.

I would recommend using Robello racing for your engine build. In fact they have used my engine model to do that kind of setup. My engine runs very well. I dont think I will EVER see 600hp at the rear wheels in my car, and if for some reason I did want to build that much RWHP for my car, hp and torque being a linear scale, I would be putting out well over 700 foot pounds of torque in the car. I dont need that much power, it would force me to rebuild the chassis of the car, and that isnt going to happen.

Speak to Dave and he will give you the quote, and if you want a really hot turbo setup I can do that for you as well.

[Drftn280zxt]

Thanks for the feedback guys. As far as turbo spool goes, if I could get the turbos spooled up so that my power is at it's greatest 3K-5.5K rpm would be ideal.(would twin T3-T4's be capable of this?) Also would this setup give me a lot of low end torque? DO you think 650CC injectors would serve it well or 750CC injectors.

 

Also Iwas thinking 15-20psi would be ideal for the setup.

 

Also anyone know of the name of the company that makes spark plug wires with the wire made of silver? (silver conducts better than copper,delivers a hotter spark)

[jeffp]

Hi there, well you dont need twin turbo's to get that kind of response that you want from the engine. Ask James what it took to get dual turbo's going on hic car, real pain in the butt. You can run 20psi all day long with a TO4E turbo configured properly. I made 413hp and 475 foot pounds of torque at the wheel with that turbo. How much is good for you? I can tell you one thing, with that much hp, you will need to reconfigure the entire running gear, tranny, diff, especially the clutch, and beef up the stub axels and make damn sure you have at least the cv half shafts. Believe me, that will keep you busy for some time. Then you will need to do work on the oil pan because if you get the car hooked up and moving with that power, the stock oil pan will run the sump dry because it throws the oil in the pan away from the pickup. You will destroy the drive line in short order if it is stock. One BIGGY, you will need a better braking system as the stock system will not work worth a damn.

So you see, to build, and it is very doable, kind of hp and torque requires just about rebuilding the whole running gear and the brakes and suspension.

The injectors, well I would recommend 72lb injectors for that application. They will provide you with that power and more. Or if you want smaller you can go with 550cc injectors and that will work as well, but you may have to run the fuel pressure higher to get the flow volume you require, and if you go that way, you will have to work on the fuel delivery system to ensure the fuel pump will flow sufficient fuel to the injectors at whatever boost levels you want to run, no guess work here, do a functional setup on your system to make sure it is delivering the required fuel.

You can see some of the crap I did to my car to get the results I wanted, and I am still not done. http://www.angelfire.com/extreme/280zxt

hope that helps.

[Drftn280zxt]

I want to make anywhere from 450-650HP. (more on the 650 side). As far as the axles go, I'll search around for a futuire beefier set,if I can go aluminum that would be nice. Pondering whether to modify the existing OEM 5spd in the future or to do a racing 6spd trans instead. I'm thinking JSK's big brake upgrade will probably do with the 12.1" rotors (of course slotted ones would be a bit better)and 4pot Wilwood calipers.

 

Simply put I want redo the car over.(simply make it better and wake it up) Susp,drvtrain,engine,trans,brakes,body,everything

 

I think of it this way every performance part with the exception of Nitrous, supercharger, and carbs.

[datsunlover]

[quote name="Mack.... the electramotive team that racced a 280zx during the 1980's was running about 600rwhp out of a 2.8L motor. no one has been able to duplicate those results' date=' ...

McAdam[/quote]

 

I had an old magasine (road and track maybe?) with a write up on that car (Im sure it was that car..) I remember a bit in there about the driver saying something like it was overheating (you think about it.. this engine was STRESSED to the max..) too the point that the valves were starting to BEND and stretch due to heat. He would go into a corner and let the car coast for a second or so (shifted down slowly) just to give it a 'breather' before getting back on the throttle...

[violacleff]

Hey JeffP, I was curious what was the most power you could safely get at 91 octane with that setup. I'm guessing you used C16 at 20 lbs of boost.

[Drftn280zxt]

so with that setup where (what rpm) would aa get good boost at with twin T3-04hybrid turbos? High(5k or more) or Medium (3k-5k). NOt to crazy about high revving engines. MOre damage if you ask me that is not neccesary.