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Discussion Starter #1
I'm getting ready to build my extra motor. I currently have delta 2000 and raised the rev limit to 6500. I know those cams can make more power with more revs.

My new motor Im planning on delta 3000 cams and would like to rev to the 7-7500 rpm range. I've seen people saying about 06 avcs valve train but I cant find much info on it.

I can't find too much for aftermarket valve train for the 253.
 

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what info are you looking for specifically? The 06 + EJ253 springs are moderately stiffer than their predecessors.

Do you need a spring that stiff? That's a question to ask whomever makes the cam. Too stiff is just as bad as too soft. You'll also want to ask them how that cam will play with your intended piston choice.

Can your engine make power that high? Depends on your throttle body/intake manifold/headwork/exhaust manifold combo. Going to take an awfully special set of headers to make power that high IMHO - and an 11 or 12mm oil pump, and a really good set of injectors, and probably something other than a stock ISC to keep idle at anywhere near a decent level
 

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Discussion Starter #4
I just saw your reply to this. My original plans of building another motor have changed. But I have to pull my motor to do the rear main, so while its out I'd like to change a few things. I'd like to rev higher, in the 7-7500 range. Even if I'm making the same power @ 6000 it would still be beneficial to me during rallyx. My concern is the top end holding together at those rpms ie. Valve float.

I've read of people using the 06 springs but I need clarification of all necessary parts to do so. While the motors out I will most likely be doing some porting as well.
 

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you biggest concern should be keeping oil cool. you dont need anything but a 10mm pump, btw
 

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I just saw your reply to this. My original plans of building another motor have changed. But I have to pull my motor to do the rear main, so while its out I'd like to change a few things. I'd like to rev higher, in the 7-7500 range. Even if I'm making the same power @ 6000 it would still be beneficial to me during rallyx. My concern is the top end holding together at those rpms ie. Valve float.

I've read of people using the 06 springs but I need clarification of all necessary parts to do so. While the motors out I will most likely be doing some porting as well.
All the same questions I previously mentioned would still apply. You would really need to ask the cam manufacturer what spring his cams need. Springs and retainers are what get changed, He should know if 06+ ones are sufficient or not

The 253 springs have longer free length (aka uninstalled), but same height when installed, and have roughly 10% stiffer seat pressure and peak pressure at full lift. You would need springs - the retainers and keepers are the same as the 251. Though doing new retainers and keepers makes sense to ensure they are fresh as well.
 

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Discussion Starter #7
Jake - I planned on a 10mm oil pump. Which is found in the wrx, correct?

I have delta 2000 cams, so I need to contact them to confirm ?
 

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IDK if an out of the box 10mm pump is going to be happy at 7500 rpm with cams - I could see it being sufficient if shimmed correctly. Balanced/blueprinted would make it even better if you have someone to do it and it's in the budget. Will depend on the ramp rate of those cams vs stock. The upside is you're only oiling 2 cams vs 4, but how those 2 new cams are shaped vs stock is where you need to examine. Another question to ask the cam manufacturer as they should have experience. Shimming is something that needs to be done carefully, by someone who understands how the pumps work, to avoid high pressure spikes and ensure the bypass works as it should. It's easy to get it wrong by just stuffing an arbitrary washer in there. Like most things when you delve into the internals, an oil pump isn't a standalone type mod - depends on your bearing type and clearance, the oil you use, whether you've got an external cooler (and how big), whether you have oil squirters or not. From there you can back yourself into the right pump. I would think at that type of rpm, particularly if it is sustained, you're using an external oil cooler and a fairly generous clearance on your rod and mains with a decently weighted oil (not the super thin stuff), along with auxiliary oil pressure and temp gauges and a way to log them. The heavier an oil you intend to run (again based on your bearing clearances and climate), the more a bigger pump (and the right corresponding ancillary parts) matter. When building this engine, or any other, one change begets another, begets another, potentially. Just takes careful planning like you're doing.

10mm is from an 02+ WRX, 04-07 USDM STi.

If you're not using an oil cooler, that changes the equation
 
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