Max cam lift before having to go with solid lifters?

[jspaeth]

I am getting ready to add some stuff to my motor....it's a GT2871R SR20 with all the supporting mods.

Going to be adding Greddy Intake Manifold, cams, springs, retainers, headgasket, etc.

Going with the Apex'i HG, 1.1 mm thick.

I am wondering....with upgraded valvesprings (HKS, Greddy, etc.), what is the MAXIMUM cam lift you can run with the OEM hydraulic lifters?

I DO NOT want to go with solid lifters at this stage, and would GLADLY take cam suggestions from anyone as well.....something that keeps the midrange torque and pairs well with the GT2871R 0.64 A/R and Greddy IM....

Thanks

[Geno750]

In my opinion, from building a car with a very similar setup, this is how I wish I did it.

Keep the stock Intake manifold
Tomei Pon cams 256/256 or 264/264
Keep the springs stock

No point in running the greddy intake manifold or monster cams with that turbo, you'd be sacrificing mid range (what that turbo is great at) for top end, and with that turbo, the gains there do not outweigh the loss in mid range (in my opinion).

As for maximum lift, it depends on more than just lift. Rampup profile, valve spring seat pressure (closed and open) all determine how much pressure is going to be exerted on the lifter.

[steve shadows]

If your SR20DET head is even 50% still stock, focusing on lift is not going to do much for HP.

It just doesn't make a huge difference on street or race srs (without ds-shrouding the valves and comb chamber re-shaping).

I would say 12 mm is overkill, you only need about 11.5 mm of lift MAX on an sr to benefit the air flow per cycle, I would focus on the most appropriate duration, the cam ramp angle or the make of the cam and shape of the power band you are looking for.

Stick to Hydros, re-shim your head (guides and shims to 0.00 differentiation) and run ras, with a rev limit set at 7950 RPMS and you will be good all day long, that what I did, car is ROCK SOLID at 400-420 whp on pump gas with stock internals.

If you are looking for power in the head, de-shroud the valves.

[jspaeth]

Thanks Steve..

Wasn't trying to FOCUS on lift, just wondering, bc one of my top cam choices (HKS Step 2) has a 12 mm lift on the intake side, and I was wondering if this requires modifications (solid lifters?)....

I would probably add BC springs/retainers, hoping to rev to close to 8K

[steve shadows]

My car as well as most of the best cars I have tuned all run HKS STEP 2, all hydro lifters, used to rev my old motor to 8K, then built another one, never had a problem.

Re-Shimming the valve guides will help insure the head is balanced if you retain hydros, then you wont need to do a valve job, just re shim once every 20k miles or so if you want. :bow:

[guitaraholic]

If your SR20DET head is even 50% still stock, focusing on lift is not going to do much for HP.

It just doesn't make a huge difference on street or race srs (without ds-shrouding the valves and comb chamber re-shaping).

I would say 12 mm is overkill, you only need about 11.5 mm of lift MAX on an sr to benefit the air flow per cycle, I would focus on the most appropriate duration, the cam ramp angle or the make of the cam and shape of the power band you are looking for.



How much HP gain do you think is possible with some head work? I am planning on going with a gt2871r in the near future, I have a spare head that I am going to P&P and swain coat.

[teamsprock]

IF your running the 2871 I highly recomend going with the JWT S4 cams. They have the most lift, and duration that I've ever seen on a hydro cam. But because of their ramp rate they can still be run on stock valvetrain. They are also great on the streets. When used with a GT30R I made 407hp at 16psi and it drove like a stock car.

On a turbo the size of a 2871 I really don't think you will see any large gains as that turbo is not maxing out the ports yet. Unless you are building a race car I wouldn't get too crazy with the head. You should have a fun and sweet setup with a 2871 and cams.

[s13silvia123]

this is so educational. i'm in the process as well

[jspaeth]

I am scared hahah...getting ready to make a huuuuuuge purchase....headgasket, cams, springs, retainers, valve stem seals, valve guides.....kinda excited

Never done headwork before, so I'm worried about ruining my perfectly clean 320 whp setup I have right now....

[besTint]

question regarding cams and lifters:

can i run solid lifters on my hks 264 that i have in my SR now or do they have different cams that work with solid lifters?

[Geno750]

question regarding cams and lifters:

can i run solid lifters on my hks 264 that i have in my SR now or do they have different cams that work with solid lifters?

You can run hydro cams with solids, its worked out great for me, and a few other people I know. Its just a bit noisy.

[teamsprock]

You can run hydro cams but the base circle is slightly smaller and the a solid cam the ramp rate is more aggressive. If you run an HKS 264 your better of just sticking with HLA's as reving higher won't make much difference powerwise. And with solids you have to re-shim the head every 3-5000 miles. If you really want to run hydro cams and solid lifter run tighter clearences that a usual solid cam. You can do this because of the slower ramp rate and base cirlce and have great results.