evildky Posted April 23, 2008 Share Posted April 23, 2008 I knwo the hydraulic head gets a lot of grief but all things considdered I've had pretty good luck, I recently trashed my motor and was going to go V6 but am currently reconsiddering, whats the most power anyone has made with the hydraulic head? if I build it I hate to think that the head would be holding back much potential power Quote Link to comment Share on other sites More sharing options...
z-ya Posted April 23, 2008 Share Posted April 23, 2008 My turbo motor has a P90A hydraulic head, and makes 250WHP at 500RPM and 12psi. The limiting factor is that I am running a stock turbine wheel, so it can't flow enough to make any more. I have a T04E/T3 with the stage 3 turbine wheel sitting on the shelf. My goal is to get that installed with a 3 in exhaust this summer. I'll let you know what numbers I get. I'm shooting for 300-332WHP at 6000 or so RPM. Quote Link to comment Share on other sites More sharing options...
evildky Posted April 23, 2008 Author Share Posted April 23, 2008 I already hit 299 whp with the hydraulic head, at the time I was low compression in 2 cylinders, one worse than the other, I am running the T304E 57 trim at 20 psi, I'm sure the loss of compression help my numbers back and I am about to build a new bottome end and trying to decide if the head has to be swapped to get intot he 400 whp zone Quote Link to comment Share on other sites More sharing options...
z-ya Posted April 23, 2008 Share Posted April 23, 2008 For that kind of power I would pick up a P90 and have port work done to it. Quote Link to comment Share on other sites More sharing options...
evildky Posted April 23, 2008 Author Share Posted April 23, 2008 I just don't understand why the hydraulic head is thought of as a weakpoint? VG's use hydraulic lifters and there are more of them north of 400 whp that you can shake a stick at, and I can replace an failed hydraulic lifter on the P90 in just a few minutes Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted April 23, 2008 Share Posted April 23, 2008 I have made 265RWHP on the P90A with stock injection and bigger turbo. Now with MSII and other goodies I am probably close to 300+ RWHP on the same old P90A. The P90A is limiting because of cam choice limitations. That's about it. Quote Link to comment Share on other sites More sharing options...
BayAreaZT Posted April 23, 2008 Share Posted April 23, 2008 evildky I'm in the same boat as you. I have a P90 on the engine now but have a spare P90a head I'm considering using when it's time for a rebuild. I know there is someone on this board that is in the 400hp range with the hydraulic lifters so I'm leaning towards using the P90a. I'm not looking to push more than 400hp. edit: Check with Doug71zt. He was running mid 11 quarter mile times with the hydraulic head. Quote Link to comment Share on other sites More sharing options...
z-ya Posted April 23, 2008 Share Posted April 23, 2008 I just don't understand why the hydraulic head is thought of as a weakpoint? VG's use hydraulic lifters and there are more of them north of 400 whp that you can shake a stick at, and I can replace an failed hydraulic lifter on the P90 in just a few minutes I don't know this for sure, but I believe the solid lifter heads can be run at a higher RPM because there is no chance of valve float with the correct springs. Of course you can get solid lifter valves to float with a high lift cam and weak valve springs. My point is that hydraulic lifters cannot react as fast as solid ones, so at high RPMs (6500+), you may get valve float. So if you need to run the engine to 7000RPM to make the 400WHP (horsepower is a function of torque and RPM) your looking for, then you will need a solid lifter head. As cygnusx1 said, you can't run a performance camshaft in a P90A hydraulic head, mainly because there is no lash adjustment. Also, you can't really observe the wipe pattern because the engine has to be running with oil pressure. I suppose you could run a drill on a distributor as you would when priming a new engine to pump up the lifters, and then check lash. It would be easier to get a P90, or convert you hydraulic head to solid lifters as many have done (search). To achieve 400WHP, you will probably need to run one of the Isky or Schneider turbo grinds, which will only work in a solid lifter head with the correct springs and lash pads. Quote Link to comment Share on other sites More sharing options...
Boosted_JDM Posted April 23, 2008 Share Posted April 23, 2008 They are good for about 350WHP, after that problems begin. They start to stick, and the car will SOUND like its going out of tune, or if its getting too much fuel, misfires, etc. 350WHP depends on mileage, and abuse. If your looking for more than 350WHP go with solid. Quote Link to comment Share on other sites More sharing options...
Doug71zt Posted April 23, 2008 Share Posted April 23, 2008 I wouldn't look at a hyd head for a serious build. You will be pretty much limiting yourself to 350-375 hp with the stock cam and hyd head. My current engine is all done by 6K - I run my best times shifting at 5700. The new 3.0 that is going in this summer is getting a P90 with an ISKY cam. Doug Quote Link to comment Share on other sites More sharing options...
WEBEZEEed Posted April 23, 2008 Share Posted April 23, 2008 evildky, dyno day is saturday..........didn't know you could build a motor that fast? lol. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.