BIG QUESTION

[nipe 1]

Ok, guys, time to ask you for an advice. On m20b27 with 885 head and mls HG would it be smart o-ringing it too? Other questiuon to discuss, I know somebody will bag me for this, BUT regarding the welding of the coolant passages, wouldn't that welding increase amount of tension in the metal? I just don't get how welding the aluminium head (quick heat up, quick cool down) can be not bad for it. Discuss please (I know it has been covered, but I'd rather hear it from people that actually have done it here in nz)

[topcat 11]

another big Q is, how much boost are you planning. head studs and a quality HG should be fine fine for 15psi.

maybe more.

O-ringing the block is done but 'usually' higher boost levels.maybe crunchy could chime in about here.

water passage welding??? this is new for me. explane some

[nipe 1]

another big Q is, how much boost are you planning. head studs and a quality HG should be fine fine for 15psi.

maybe more.

O-ringing the block is done but 'usually' higher boost levels.maybe crunchy could chime in about here.

water passage welding??? this is new for me. explane some

some people weld the water jackets around the cylinders on the head and only leave tiny holes to match those on the HG which apparently increases the m20 head strength, but any welding, in my eyes, increases the stress in the metal... Now the boost, I would love to be able to put up to 18psi in it max, don't think any more than that is reasonable really. Would be likely running 10-12 psi on street tune and more if I need. For the race tune.

[No name user 379]

I would go with BM Weapon on this it comes down to what your doing and as he's stated studs MLS more than covers most people at that level,as for the welding i would have to agree these alot of heat going into covering each hole thus i would heat treat it afterwards but forgive me if im wrong but arnt the heads prone to cracking under the cams towers?

Dont take this wrong but the difference between a race tune and great tune is the same thing, nothing.

The tune is done on whatever octane you chose will determine what it is regarless, theres alot more to making power than sticking more boost in it i did a stock maloo ute on pump gas running 12psi making 500kw wheel.

The art of making power is thinking smarter!

[Mike 1]

dont o-ring if you're planning on using an MLS gasket. pretty sure most they explain this on manufacturers websites

[nipe 1]

Guys, thanks a lot for your input, that is pretty much what i was looking for, will be using my mls hg and studs. What I mean by street tune and race tune is driveability, on the street I won't need a lot, otherwise I'll just get in trouble, I will still wait until I finish the thing and see how I like it, in the meantime I just want to build as much reliability in it as I possibly can, therefore the limits I set for the engine at this stage might be quite a bit over what it will actually experience. Still discuss further if you have anything to say, I'm always happy to listen!

Other thing that I was told is worth doing is getting stainless steel valves instead of factory ones, what do you think?

[No name user 379]

Again for what your after just use stock valves i can give you a big shopping list of what im doing but by the time your finished youll be amazed how it goes and what it costs, all the hidden things soon add up

[nipe 1]

Again for what your after just use stock valves i can give you a big shopping list of what im doing but by the time your finished youll be amazed how it goes and what it costs, all the hidden things soon add up

That would be perfect if you could, thanks!!!

[nipe 1]

Anyone has any more inputs? Please feel free to discuss!

[e30ftw 410]

The MLS' Headgaskets on m20's are prone to leaking from the oil drain jackets on the exhaust side of the head.

[polley 916]

Welding the water jackets is to increase the surface area to clamp the head gasket, its not uncommon for them to push out at the water jackets under boost. But in saying that a few people have made alot of power without even opening the engine up on m20b25's, just standard head gasket and ARP studs.

[CamB 48]

Based on dudes overseas (so depends whether you trust the internets or not):

- 18psi is fine as long as the turbo is big enough and has a large enough exhaust side to avoid too much backpressure

- if you do this, with a properly tuned M20B27 you'd have at least 300hp at the wheels with 18psi.

They heat the head up before welding. Either way - if Steve (crunchy) says don't weld the head, don't. He's the man who knows.

Its probably worth noting that having a boost level goal isn't really the right way to approach it - a little turbo at 10psi makes power differently (and probably less of it) than a big one - you should pick a power level and then worry about what size turbo (and what other add-ons) would be required (and how suitable it is for your intended driving).

Edited December 3, 2010 by CamB

[nipe 1]

Thanks guys:) Got everything together really, just few small bits to go. BUT I got 2 turbos i can use, either holset h1c (faster spool, lower max power level) or holset hx40 (later spool, higher level of power), I'm leaning towards h1c for driveability reasons, but if anybody can give me any more advice on that it would be helpful too!

[CamB 48]

How big is the exhaust housing on each (its the two digit number by the inlet of the exhaust housing)? Good turbo choices btw.

[polley 916]

And the big Q, what are you going to be doing for tuning?

[nipe 1]

And the big Q, what are you going to be doing for tuning?

Are you asking what engine management am I going to be using?

CamB: one is 18.5cm and other I'll have to check

[nipe 1]

Any more thoughts?

[CamB 48]

Any new information?

[|ncary 0]

They want to know what ECU you are going to use nipe.

come on richard

[nipe 1]

Megasquirt PNP ecu. The turbo housings from what I could find are: HX40 is 16sqcm and H1C is not clear, on outside it says 18.5sqcm, but inside, where holsets usually state the housing size on the H1C it says 18, so I'm not 100% sure if it's 18 or 18.5. Hope that clears few things up. Thanks guys.

Edited December 14, 2010 by nipe

[nipe 1]

Can anybody please shed some light on the turbo choice? I'm leaning towards the h1c to get the earlier spool up, but from what i read on the forums the hx40 isn't much worse either, any of you guys tried them? Crunchy?

[No name user 379]

Can anybody please shed some light on the turbo choice? I'm leaning towards the h1c to get the earlier spool up, but from what i read on the forums the hx40 isn't much worse either, any of you guys tried them? Crunchy?

opps sorry been rather tied up with work, what power are you aimming for and any future mods as such?

theres manay many different turbos to pick from for different reasons like budget etc.

[nipe 1]

Well it would be nice to get 400hp at the wheels, but first of all I know it's a bit unrealistic and secondly I would be more interested in the torque than horsepower, so I started leaning towards hx40 since it delivers more air compared to the h1c and I don't think the spool up difference is dramatic, therefore it seems more efficient to me at this stage. Regarding future mods, I'm not sure what sort of mods you mean, I just want to build it once and do it as good as possible the first time. Please feel free to suggest anything.

[nipe 1]

The hx40 that i have is the 8 blade one, which apparently is the least flowing

[polley 916]

Even a 8 blade hx40 will be enough for 400hp.