PSI, the manufacturer, told us the springs we're installing are good to .625".

 

Is this set in stone, as i would like to know if i can run a T-rex cam with these springs and heads or would i have to buy new springs as soon as i buy a new assembled set of heads.

 

The springs currently used are PSI 1500 series - they are a beehive w/120#@1.800"
and 360#@1.175" max lift is .625" coil bind is at 1.100"

In our never ending search for the optimum setup, we are also looking at some new spring offerings that were proposed at the PRI show.

The current package is pretty nice though!

 

Any chance of offering a dual spring, particularly on the 225's which I assume are geared more towards big cube motors which require a lot more cam. I like the safety aspect of dual springs. The performance of the PSI springs loooks good though.

 

Any rpm limitations? 6500? 7000?

 

I think in this case you will have to get it from a sponsor and they will get it bare and install their own duals springs, valves, etc. That's what I'm doing, TSP will be doing my Dart 225's with larger valves (2.080/1.60) hopefully and a stage 3 port job. I need these to flow as much as they can for my 402 And my Ed Curtis cam will be large, so I will need the PRC dual springs, etc. on there.

 

6500 rpm = no problem
7000 rpm, I honestly don't know ... I will have to check with the guys in the cylinder head dept. & get back to you. I would think that the rpm limitation would rest more on the lifter than this particular spring though.

 

Those springs must have alittle more in them than stock. So 6500 sounds reasonable and possibly safe with a cam under .600" lift.

Orange peel: Bigger intake and Stage 3 porting? In my case, I will definitely clean things up, but what does Stage 3 mean on a head that almost no one knows what to do with as of yet?

What happens when Stage 3 gets you 20 hp less than Stage 0? Just curious as to who would offer this blind, or am I missing something?

 

TSP Has some Dart 205's right now they have been working their porting stages on I guess. I just know they will go bigger valves and more porting/hand finishing, so I honestly don't know what the stage 3 is, but that's what they told me If stage 3 gets 20hp less, I will call it Stage -3 then

 

Hey, I don't know squat, but personally, I would want to see some serious real world results both on a dyno and on the pavement with these heads, before paying the big buck for Stage -3's (That's funny, unless it's your nickel)

Some stuff is obvious, but some stuff that has been traditionally done to OEM heads may not cut the mustard with these (unless you want them to preform just like OEM heads...hahaha... )

I kinda like the attitude though..."I've never seen a set of 225's but I can tell you this much. Our Stage 3 porting will be the cat's meow. Now how many do you want?" (Not directed at TSP, just all in good fun... )

I should be seeing my first set on Thursday, with another set shortly afterwards. Hope they look and perform as good as I think they will.

I can't wait to Stage 3 them.. Hell, send me your 225's I'll Stage 3 them and then pay you $500 to take them back...

 

ok, can you help me. Can i get the 225 and use it on a stock bore? Whats the compression ratio? how far can i mill? Will i get the newer ls1 valve size? What specs on the valves should i buy for your stock head?

 

Yes, you can you the 225's on the stock bore.
The heads have 62cc chambers. You will have to figure your compression ratio off of that. It will vary dependant on bore size, gasket thickness, actual deck height, etc.
For every .0055" flat milled you will drop 1 cc.
8mm guides come standard
We call the valve lengths out as 4.900" int / 4.930" exh

Hope that helps!

 

Thanks, What size valve? 2.05 ? 8mm is the normal ls1 valve stem? And stock pushrod length is cool yes?

 

205 heads have 2.02"/1.60" valves
225 heads have 2.05"/1.60" valves
Stock pushrod length is fine.

 

Thanks last one. Bare head has valve seats installed?

 

Yes, bare come ready to assemble - guides & seats installed. Valve job (5 angle intake/2 angle to a radius exhaust) done as well.

 

Can't wait to see a set in person!!!!

 

when shimed the 918's can handle alot more then advertised too

 

The current PSI spring with its spring diameter installed at 1.800 with a coil bind of 1.100 giving a .060 clearance average would allow .640 lift in reality, but wouldwe run that spring on that much lift, no it wont last and wont like the higher rpm. The newer spring has better material and will be able to handle the higher lifts.

 

If I ordered a set, what is the wait period now?