Engine Building Questions

[Dragon240]

Ok.. So I came across this on the net: I'm wondering what everyone thinks of this list of mods. I want to do similar but not by these people. Only thing that bothers me really is the .040 overbore. I'm planning to turbo and maybe (not too sure) a light nitrous shot once I get the engine built.

Opinions/Suggestions? No flames just a thought

Here's the mod list, rather then have to go to another link, I just copied it here...WD

.040 overbore 10.5:1 JE Pistons· Total-Seal Ring pack· Race prepped stock rods with ARP bolts. Detailed and Heat Treated crankshaft· Lightened stock Flywheel· Balanced and Blueprinted rotating assembly· Race Ported, Flowed, CC’d Cylinder Head· 3 Angle racing valve job with hand lap and back-cut· Secondary Butterfly system removed.· Intake manifold match ported.· Throttle body opening enlarged for 65mm T/Body· Camshafts reground and indexed.· Valves shimmed and adjusted.· Heavy Duty Head Bolts.· Felpro Gaskets

$3900.00 complete

Optional Upgrades:Ceramic coat pistons for Nitrous use $49.00 eaHigh Heat coat valves for Nitrous use $9.00 eaEnlarge stock throttle body to 65mm $250.00

Individual components prices Turbo and Non-Turbo vehiclesTubular turbo exhaust manifold. High heat coated $750.00As above but for External Wastegate $850.00Turbonetics Deltagate Wastegate $250.00T3/T4 turbocharger assembly. For external wastegate $750.00 with internal dual port wastegate $895.00 Both are complete with all needed flanges, etc.Spearco intercooler assembly with proper tanks $575.00Forged piston set (8.2:1 c.r.) set of 4 $525.00

Special turbo ring configurationForged piston set (10.2:1 c.r.) set of 4 $550.00Nitrous design piston set of 4 $575.00 Total-Seal ring set $139.00Total-Seal Nitrous Ring Set $169.00High Heat Piston top coating for Nitrous use $49.00 ea.High Heat Valve coating for Nitrous or Turbo $8.00 ea.Auxiliary injector system. Injector controlleronly $365.00

fuel injectors with clips 4@ $69.00 ea. injector bosses 4@ $35.00 ea. Fuel rail assembly with fittings $110.00 Weld injector bosses into your intake manifold $100.00Additional Bosch inline fuel pump kit $199.00Rising rate Boost-Referenced fuel pressure regulator $219.00Compressor bypass valve

HKS SMALL $119.00HKS RACING ADJUSTABLE $189.00ITG turbo air filter $129.00K&N Air filter $39.00Turbo grind camshaft(s). Ground on your cores) KA24 $119.00 KA24D $169.00TEP Pro-Grip Clutch Kit $395.00 More holding power than Centerforce and easier to drive and more reliable than RPS turbo clutch.Header for 16v 240sx through 1996.Up to 1995 is a bolt on with smog95-96 will not accept EGR pipe and “B” pipe to catalytic needs to be extended.All 14ga construction. Has all needed smog hook-ups and lower pipe to catalytic converter.A truly nice piece. Not like that crappy S&S header that does not fit. Available coated or un-coated Un-Coated $269.00 Ceramic Coated $350.00

Adjustable fuel pressure regulator $69.00For use in normally aspirated system. Increase fuel pressure over stock to compensate for large throttle bodies, free flow exhausts, high flow air filters, etc. Installs inline with stock regulator and can raise pressure up to limit of pump.

[WDRacing]

Well, lets look at the whole list.

40 over with 10.5/1 CR pistons is horrible with boost in mind. You'll need to stick to a more friendly CR like 9.0/1 to 8.0/1.

The rest of the engine mods look alright to me. The price isn't to bad either.

For options the only thing I don't like I don't like is the Aux Injector with controller. But thats just my personal preference.

WD

[Dragon240]

Right that makes sense. Its actually just a N/A build up on the motor. It has other pistons listed for 8 or 9 to 1 ratios. Whats bad about aux inj. controllers? I really know nothing about those other than that they exist..

[Dragon240]

Oh and although not directly related.. I've seen the available replacement 5th gear thats around.. How bad would it mess me up if I just got it and no ring/pinion gears or rear end work? What im looking at is the transmission is rough and if I get a rebuild id like to throw that in while its down. I wont be racing for the time being just want to make sure I can still run ~90 on the interstate on the long drive back home...

[Dragon240]

Few more questions..

What are:injector bosses 4@ $35.00 ea.Compressor bypass valve

and Which is Better - Internal or External wastegate?

[encasemyheart]

Which is Better - Internal or External wastegate?

External, in fact, I don't believe there are any performance benefits to using an internal. External will flow more, eliminating boost creep. The internal dumps the wastegate gasses right at the outlet of the turbo, ideally if it were routed into the exhaust system, it wouldn't actually mix with the exhaust gas until it was about 18" away from the turbo, not at the inlet. Even more ideal is that with the external you can route the piping under the car just to vent, maybe even with it's own small muffler. This is the best for performance, which is virtually impossible for an internal model.

The only benefit for intenal is the start up price, but if you go above 10-12 psi you shoul dget an external anyways, or at least mod the internal to flow more. Either way, the external is still better.

[dreamsOfSkylines]

I thought venting the wastegate into the piping before the inlet would keep the turbo sppoled while shifting gears. Could be wrong though...

[encasemyheart]

The wastegate won't even be operating between gears, only at full boost or close to it.

You can vent the BOV into the intake tract right before the turbo to help a little bit though, that shoots air out when you shift.

[midnight brother]

If you rely on a fifth injector and something happens and it fails there goes your engine. You're engine wont always go but that sentence was supposed to scare you hehe. Much better to just use bigger injectors.