34 replies to this topic

[haggi961]

Im just wanting to know a bit of info on these as im thinking about getting a set. What do they do is my first question, as ive read somewhere that you can take the rev range to over 8000rpm safely with these fitted. Do they make much difference to a 300bhp sc engine with all the other goodies and is it worth the £300 price tag? Thanks for any help as i cant find much info on the Internet about them.

[VX-GT]

This is a supporting part Is the rest of your engine configuration capable of exceeding 8000rpm? If so, you will need this part! If not, then NO! The RPM is critical THIS PART ON ITS ON WILL NOT ALLOW YOU TO REACH +8000RPM The power/torque output is not the critical issue, The RPM limit IS

[haggi961]

the stuff i have are Eagle conrods, Wiseco pistons, APR head studs, Blower camshafts, Supertech valves springs, Gm racing valve spring kit and will also be getting balancer delete, lighten flywheel, uprated clutch, uprated fuel pump, 3 inch exhaust.

Edited by haggi961, 19 January 2011 - 11:50 PM.

[TheHood]

Dr Lee is probably about to post something about piston velocity

[VX-GT]

None of the above parts will increase RPM The only thing that allows one to govern RPM, is mean piston speed it is recognised that 25 m/s is the common limit therefore if your are running standard N/A crank @94.6mm the limit is 7825rpm the only way to increase is to change crank to a lessor through (example 2000cc @86mm) SO these gears (quoted) are NOT required But If you think you need them, then buy them, as they will do no harm apart from your bank balance

[haggi961]

None of the above parts will increase RPM The only thing that allows one to govern RPM, is mean piston speed
it is recognised that 25 m/s is the common limit
therefore if your are running standard N/A crank @94.6mm
the limit is 7825rpm
the only way to increase is to change crank to a lessor through (example 2000cc @86mm)
SO these gears (quoted) are NOT required


But If you think you need them, then buy them, as they will do no harm apart from your bank balance

Thats a good enough answer for me not to get them, so thanks for the quick reply.

[The Batman]

You will max the supercharger put way before you need these

[Winstar]

You will max the supercharger put way before you need these

no the real restricion is the inlet manifold you can always gear the SC down to stop it going above max rpm. Where as the gas velocity will choke the inlet manifold at just over 7krpm no matter what you do else where.

[vocky]

excess engine heat causes the standard oil pump gears to crack (according to GM), so if you plan on abusing your engine then they are a good idea. MaxR has them in his track vx220 for that very reason and I also fitted them in mine for piece of mind.

[Exmantaa]

You will max the supercharger put way before you need these

no the real restricion is the inlet manifold you can always gear the SC down to stop it going above max rpm. Where as the gas velocity will choke the inlet manifold at just over 7krpm no matter what you do else where.

, but real choke restriction is in the head (small exhaust ports). Solve that first, with a good exhaust, before you bother with the inlet. (And as with all tuning, it's a combination of restrictions you need to work on...)


@ Vocky; where did I see that pic of those pitted pump gears? Or was that maybe from Alanoo?

Edited by Exmantaa, 20 January 2011 - 11:26 AM.

[siztenboots]

You will max the supercharger put way before you need these

no the real restricion is the inlet manifold you can always gear the SC down to stop it going above max rpm. Where as the gas velocity will choke the inlet manifold at just over 7krpm no matter what you do else where.

, but real choke restriction is in the head (small exhaust ports). Solve that first, with a good exhaust, before you bother with the inlet.


@ Vocky; where did I see that pic of those pitted pump gears? Or was that maybe from Alanoo?

I think I posted it in a discussion about 20micron filters vs 5 micron. I think original was from Alanoo.

[alanoo]

Even by OE standards, they are a low quality part
Unhardened, untreated... there's not many engines with such raw parts these days

Edited by alanoo, 20 January 2011 - 11:32 AM.

[Winstar]

, but real choke restriction is in the head (small exhaust ports). Solve that first, with a good exhaust, before you bother with the inlet. (And as with all tuning, it's a combination of restrictions you need to work on...)


@ Vocky; where did I see that pic of those pitted pump gears? Or was that maybe from Alanoo?

The ports aren't the best but the power curves of even people running ported heads drop off in power over 7krpm

There was a online artical that tested mods to the LSJ engine that logged the pre and post CC pressure against rpm and you could see in all cases the curves rapidly diverge at over 6.5krpm

[VIX]

im thinking about getting a set. What do they do

Really, you have to laugh!

[slindborg]

pub spec sheet additions FTW

[Exmantaa]

Any difference in parts/material between the Z22SE and f.i. the Saab B207 or Z22YH pump gears??

[Exmantaa]

, but real choke restriction is in the head (small exhaust ports). Solve that first, with a good exhaust, before you bother with the inlet. (And as with all tuning, it's a combination of restrictions you need to work on...)


@ Vocky; where did I see that pic of those pitted pump gears? Or was that maybe from Alanoo?

The ports aren't the best but the power curves of even people running ported heads drop off in power over 7krpm

There was a online artical that tested mods to the LSJ engine that logged the pre and post CC pressure against rpm and you could see in all cases the curves rapidly diverge at over 6.5krpm

Going off topic here, but interested in that article.
And not a fan of the LSJ manifold design, but it's aIso a matter of blower efficiency. If that dropsat higher rpm/higher boost, air temperature rises and the measured pressure pre-chargecooler shoots up. (In the US, 2.0LSJ's reach >350WHP with the TVS SC on a standard manifold.On E85 though.)

Back to the gears...

[techieboy]

pub spec sheet additions FTW

Tend to agree. My oil pump gears survived the engine eating it's bearings with barely any damage. Just light scoring in a couple of places. Just used replacement OE gears on the new rebuild.

[haggi961]

im thinking about getting a set. What do they do

Really, you have to laugh!

you have to ask these things as you never learn otherwise. There is not a lot of info about these, and i have read they are worth buying if you are sc your car and aiming for a lot of power. So i thought i may as well buy some for when my engine gets rebuilt as then if i did need then in the future i wont have to take my car apart again.

[vocky]

Any difference in parts/material between the Z22SE and f.i. the Saab B207 or Z22YH pump gears??

the z22se oil pump is best regarded as the 'early spec' pump, the saab B207 and z22yh both use the same revised 'later spec' oil pump.

the GM Racing oil pump gears are billet, the standard are quite poor quality in comparison