51 replies to this topic

[speedster]

I need some 2013 advice on cams for a 'high' revving NA (7800rpm?). I'm currently running with a dbilas with a rather large throttlebody but plan to go ITBs.
I have Natrium-cooled exhaust valves in a Kokill casted head, a L61 Engine Block, Eagle Chrome-Moly Crankshaft, Eagle Chrome-Moly connecting rods, Wiseco Pistons (CR 8:9:1 ), Clevite Rod and Main Bearings bound together by ARP Head Studs. Fast road is with good torque is what I'm looking for. Here's some profiles that looks interesting

1. http://www.catcams.c...log/4603113.pdf

2. http://www.catcams.c...log/4603114.pdf

[techieboy]

Bin your Wiseco pistons (or flog them to an SC'er) and replace them with higher compression versions, if you're planning on getting any NA power.

[oakmere]

Such low comp pistons will kill N/A power or dose the head gain it back. Alanoo was pushing over 8000 rpm on the Schrick.

[speedster]

Bin your Wiseco pistons (or flog them to an SC'er) and replace them with higher compression versions, if you're planning on getting any NA power.

Good point. Engine was original intended for an SC application.

[speedster]

Such low comp pistons will kill N/A power or dose the head gain it back. Alanoo was pushing over 8000 rpm on the Schrick.

That's close to the limit. Some test data I've seen indicates the crank exits the engine at around 8200rpm.

[siztenboots]

any good ?

Part # 88958620
Ecotec Crankshaft, billet steel
Internally balanced, full-race, billet 4130 steel crankshaft with
1.888" rod bearings and stock-size main bearings.
Reduced stroke of 3.505" for high RPM use.

[The Batman]

Keep the pistons if you have already fitted them and skim the head

[speedster]

any good ?

Part # 88958620
Ecotec Crankshaft, billet steel
Internally balanced, full-race, billet 4130 steel crankshaft with
1.888" rod bearings and stock-size main bearings.
Reduced stroke of 3.505" for high RPM use.

I'm OK for crank
Stroke reduced by the rods of crank profile?

[speedster]

Keep the pistons if you have already fitted them and skim the head

hmmm... Interesting.... have to take the head off so might as well as take it that step further and replace the pistons?

[oakmere]

Alanoo had the same issue an got low comp pistons by mistake. He skimmed the head by 1.4mm which is the max before you hit the oil restrictor. http://www.z22se.co....r-project.6314/

[The Batman]

Keep the pistons if you have already fitted them and skim the head

hmmm... Interesting.... have to take the head off so might as well as take it that step further and replace the pistons?

Might save time and money though..

[speedster]

Keep the pistons if you have already fitted them and skim the head

hmmm... Interesting.... have to take the head off so might as well as take it that step further and replace the pistons?

Might save time and money though..

Building it myself so shouldn't be too much on an addition plus I can sell the Wiseco pistons (brand new) to recoup. Plus it's a SAAB head I have so I really don't want to mess with it coz no idea how it's going to preform.

Anybody know where I can pick up 11:1 pistons?

[techieboy]

Anybody know where I can pick up 11:1 pistons?

Cheap option is rods and pistons from a Z22YH engine (no idea how suitable they are from a strength point of view). Expensive option is to get some custom made as Vocky did.

[The Batman]

The z22yh are meant to be good for 300 Not that you will make near that though so super safe for na!

[oakmere]

Just get the std 10:1 pistons and do a 0.75mm skim like I did. Should get you around the 11:1 mark.

[oakmere]

Also make sure you fit uprated valve springs. You will get float above 7200 rpm.

[NickB787]

I have some oem pistons which you can swap with me for your low comp ones seriously if you want standard you can have some which are in the shed, 30kish on them, just pay postage

[vocky]

z22yh pistons and rods are the cheapest way to get 11:1 CR

As for the cams, I think CompCams stage 3 are probably still the best available, the schrick are similar to stage 1

[speedster]

Just get the std 10:1 pistons and do a 0.75mm skim like I did. Should get you around the 11:1 mark.

Also make sure you fit uprated valve springs. You will get float above 7200 rpm.

I have some oem pistons which you can swap with me for your low comp ones

seriously if you want standard you can have some which are in the shed, 30kish on them, just pay postage

z22yh pistons and rods are the cheapest way to get 11:1 CR

As for the cams, I think CompCams stage 3 are probably still the best available, the schrick are similar to stage 1

[2-20]

Please be advised that the CR advertised for Wiseco pistons is with a 1mm thick gasket. A Z22se or Z22yh head gasket is not 1mm thick