SAAB 2.2 Hybrid engine build

vocky

alfa 2.2 JTS has a tubular manifold with a built in cat, so the pipes are big but short, the cat points directly downwards and the bend is below it, so no good for fitting to a z22se :thumbdown:

exmantaa

vocky said:
Saab exhaust ports are the same size as the z22se, but there is more material which can be removed on the saab head to make them bigger.

I would not advise going any larger than the z22se exhaust gasket size on a z22se 'lost foam' head.

Even the Saab 'sand cast' head has it's limits. It is not possible to open the Saab exhaust port to the size of the alfa exhaust gasket, so I left a 2mm gap all the way around - you can just make out where I scribed the alfa gasket size onto the head in the pics above.

I assume you also did remove a lot of material from the bowl area? The general idea from the US LSJ tuners is to not excessively open up the gasket area (slows gasses too much...), but the shape and volume of the exhaust bowl area is where the real flow gains comes from...

Any flow numbers pre and post porting??

vocky

doesn't the 3" exhaust work better than the 2.5" exhaust on a SC, so maybe thats a myth dunno..

I used a metal washer the same size as the valve seat opening and then removed material from each port until it could pass all the way through, now I have unrestricted flow through the head, the bowl area did require some work

rushy

vocky said:
alfa 2.2 JTS has a tubular manifold with a built in cat, so the pipes are big but short, the cat points directly downwards and the bend is below it, so no good for fitting to a z22se :thumbdown:

Sounds just like my Z22SE in the Vec C, it has a manicat.

vocky

the new wiseco 11:1 pistons and GM racing valves arrived today, so I dropped off the parts at the engine shop, hoping to have them back late next week 😃

NICKYB

drool.gif very nice!

alanoo

Why only 11:1 ? notsure.gif

vocky

My engine has a skimmed head so probably has around 11.5:1 CR dunno..

I'm quite happy with the engines power, because the long 4-2-1 and Alfa close ratio gearbox make it so nice to drive I decided just to improve the exhaust ports and fit the GM Racing valves whilst it was apart then leave the rest alone :silent:

alanoo

Ah, I thought this particular head was from a "new" Saab engine and that it wasn't skimmed

nickb777

Be interesting to see what you think to the GM valves , what is the difference in size to the standard Saab ones and what about clearance ? ( 8.9 pistons) 😃 Just thinking out load I would like the gasses to leave a bit quicker

vocky

alanoo said:
Ah, I thought this particular head was from a "new" Saab engine and that it wasn't skimmed

I was very lucky as the valve failure was at 2000rpm, the saab head suffered only minor damage - one valve seat replaced and a dent welded up.

alanoo

Hum, maybe I should replace my exhaust valves as soon as possible so (are OE ones, as the SiValves were out of tolerance for the exhausts) :o

nickb777

Why you go for .5mm instead of 1mm oversize? thought you would get better flow with 1mm

winstar

nickb777 said:
Why you go for .5mm instead of 1mm oversize? thought you would get better flow with 1mm

Probably as the +1mm are stainless not inconel, there is a massive difference in strength, heat transfer and durability.

vocky

winstar is quite correct :clap:

plus they will flow about the same because the main restriction is the size of the valve seat opening dunno..

alanoo

winstar said:

nickb777 said:
Why you go for .5mm instead of 1mm oversize? thought you would get better flow with 1mm

Probably as the +1mm are stainless not inconel, there is a massive difference in strength, heat transfer and durability.

I think Ferrea has +1mm valves in a good alloy, not much more expensive than the Supertech/GMR stuff.

Custom valves are not that expensive anyway, I'll try +1mm flat face valves for my next engine

cavaddict

Am at the stage of porting on my B207 head. Is it worth changing the valves for oversize to make it breathe easier, or is there really not much to be gained? Also, if i did go oversize, which valves are best? Should probably mention i'll be using Comp cams too.

alanoo

If you stay N/A, the OE size valves are already big, these are the same size as on a Honda K20A... good enough for around 250hp, so not needed

A SC engine with a well ported head will benefit this a lot more

vocky

the standard saab valves are much better than the z22se,plus the exhaust are sodium filled too 😃

techieboy

alanoo said:

A SC engine with a well ported head will benefit this a lot more

Standard valve sizes on my SC and getting the same power as Lee's SC'd VX with +1mm valves, so not sure it makes a huge difference with the M62. Might make more of a difference with Nick's Harroped beastie.

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