ZSaint

Think about all of the parts you can find on this web page. Where was this when I was racing? Ain't computers neat!

I will call tomorrow. Thanks for the info!

I am looking for a P90A complete head. If I can find one, I will install the hydraulic cam and see if this head works. If the lifters still pump up, there is a major problem with the installation. I can take the lifters out and modify them into solid adjusters and install them with solid WEB cam. I win i either case.

I see your point. I am under the gun a bit on the Z. I took it to a shop for the exhaust system to be installed. Once the 2 1/2" system was in place, I fired the car up. I was going to drive it back to my shop about 8 miles away. I cannot get the car to run good enough to drive it back. I need a trailer and tow car, again, in order to get the car back to my shop. (It is still at ZTherapy's shop) I first ordered a new oil pump. That took a week. When I fired the car up it did the same thing. I talked with Bobby Haney about the engine and he recommended checking valve spring pressure. Sure enough it had stiff springs. I ordered new springs and that took a week. I put the 210# springs back in it and it did not work, either. Now I am waiting for Raver to answer. I first called them 2 weeks ago and they never responded. I called again and got the new message about using their email address. I sent a message. Two days later I sent a second message. Patti responded but said Vernon would get back to me. That was on Thursday. I guess I could keep trying all of these things that people "recommend" but it is costing me money and time. If you say I am in a hurry, you are correct. I have been fighting this situation for over 3 weeks. I have found only one person who ran a solid cam in a P90A head and his idea did not work out. If I do not hear from Raver, where do I go? Ron at Nissan? I need definitive information on this head.

All I know is they are going out of business and have cancelled their phone. I sent them an email. They notified me that they got my message but never responded to my concerns. No answers about this head and my problems. Maybe they will contact me on Monday. I will no longer need their help. I am killing the hydraulic head idea. It sounded like a great head but it was not to be.

This head does not work. We changed the valve springs from 270# down to 210#. It made it worse. The lifters pump up faster with less spring pressure. We are now going with solid lifters. I will change the springs back and adapt the hydraulic bosses to accept the solid adjusters. I have worked 14 months on the car so a couple more days will not make a difference. Too bad Raver Motorsports did not have this engine in their shop. It would not have worked with any solid cam. WEB Cams told me it would not work. I guess I should have listened to them.

Here is what I am thinking about this head. I believe Raver had set this head up for a high lift cam. When I purchased the head, they took the big cam and lash pads out and intalled a milder cam and lash pads. I do not feel that they changed the valve springs. This engine is bleeding down instantly when you start turning it over. The only thing this can be, IMHO, is too severe valve spring pressure. What do you guys think?

I am thinking I have too stiff a spring in the P90A head. (bleeding down) I am looking for the specs on a stock spring: Spring height installed 0D of the spring I am looking to order a set of 90-100 open and 230-240 closed springs. Can someone give me the info or give me a link?

I have heard from Raver. Vernon is looking at the problem and will be getting back to me. I hope it is soon!

I have company right now so I cannot get over to the shop until Sat. I will blue the position of the rocker pad and measure. I have a set of the correct lash pads on their way. I will let you guys know when I solve it!

I sent another message yesterday. No response so far today. You cannot get them by phone. His wife (phone lady) is very protective. Here is another theory... What if Raver installed too thick a lash pad in this head? I remember he had to take the big cam out and install a new milder cam for me. He said he was also taking out the thick lash pads. I wonder if maybe he left the longer lash pads in the head. Would that not account for the build up? If the valve is too long, I am thinking the lifter would be out of sync with the bleeder hole in the head. Whaddy you think?

Great! Now I have input from SideShowBob. What's this world coming to?

I am just about ready to give up on these lifters. I have ordered a set of lash pads for the .450 lift cam and a new set of mouse springs. I think I can find 12 solid adjusters around the area. I feel it is much better to have solid lifters and a little valve rattle and know they are working correctly. I have not found anyone who really knows what to do with this head. It is a real pisser! I spend 14 months restoring my 240Z and cannot drive it because of some set of trick lifters. Raver Motorsports doesn't respond. Can't get any real info on these things. Time to dump them!

Who do I contact other than Vernon at Raver. He is not responding. Will Ron at Nissan know about these hydraulic lifters?

I got some info sent to me by a car-building buddy. It came from The Datsun Workshop. Three things that cause "Bleed Down" are 1) Low oil pressure/volumn. I have installed a new turbo pump with 75#2) Bad lifters All of my lifter are either bad or there is another problem AND 3) One of the problems with running these Datsun lifters is "too much valve spring pressure". This causes the lifters to "bleed down". I have sent Vernon an email to get his opinion on the head. I also asked him about the springs he installed. This 'Workshop' info states that 100-110# closed and 230-250# open is the max you can run. (before you experience bleed down). Stock ZXT springs run 70-80 and 160-170. I am wondering if they intalled some of these 270-300# valve springs? I think that is what comes standard with most high-lift cams. I am guessing that either there is blockage on the oil system that keep oil from flowing out of the lifters or it is too much spring pressure. Because it starts right up and runs well for a short period of time leads me to the conclusion that my springs have too much pressure. What do you guys think?

I finally have the hood fitted. I removed the grill, took the bumper off and turned the brackets over, left to right. I had clearance on the hinges now. After making that change I still had hood alignment problems. I thought the hood did not adjust where it mounts to the hinge. We had moved the hinge as far down and forward as we could get it. We found a HUGE amount of play at the hood mount. We loosened the hood there and moved the hood forward (Pointing the front of the hood down) and tightened the hood. Wham! The hood finally fit. I remember one of the guys (Beandip) reminding us of that: There are two places for adjustment... The hinge and the hood mount. Everyone must remember that the next time "hood adjustment" comes up on this forum. Also, remind all that those bumper brackets will fit side to side but, they need to be bolted in with the thinner side up. These are the two bits of info people need when they install the hood and bumper.

The head has been converted to an internally oiled cam. The exterior cam oiling passages have been blocked off. This is a stock-appearing engine with dual SU's. The short block was put together by Hatch Engine Service. The head was put together by Vernon at RaVer Motorsports. This camshaft has .450 lift. WEB Cams said they did not think it would work before I had the egine running. I have built a couple of Chrysler engines, a 340 HyPro and a 360. Both of these engines have special hydraulic lifters for the high lift camshafts. They are adjusted as needed. You crank the adjuster down until the engine misses and back off 90`. There is no such adjustment on the Datsun lifters. Are you saying that I am not getting enough oil flow to the lifters? Where would look for a blockage? Oil is flowing into the head, the cam is oiling and the lifters are getting oil. I think it is working properly. I feel the solid cam will not work with hydraulic lifters. They do not work in any other engine so why will it work in the L6? WEB Cams said exactly that when I talked to them.

Blakeney has it right. Lack of compression means the lifters are pumping up and not releasing. I have installed a used turbo pump and then a new turbo pump. They both have the same result. I do not have any "adjustment" on the Datsun lifters. I know you have to adjust the lifters on a Chrysler but this Datsun does not have any adjustment. I think what is happening is this... The solid cam has .008-.010 valve clearance. The lifter tries to expand for 'zero' clearance. It continues to pump up until the valve will not close. I am putting the solid adjusters in place and setting the valves. I think this will solve the problem.

I agree. I have ordered a set of .150 lash pads, mouse springs and adjusters to convert this head to a P90. I do not think this will be too difficult a task. I was kinda looking forward to not having to adjust valves, but I guess that is all part of running a Z. Raver Motorsports put this head together. It simply does not work. I guess I will be selling these lifters on eBay, soon!

I am not aware of anyway to increase or decrease the valve adjustment with hydraulic valves. Do they need to be adjusted? How do you do that? Is there anyone out there that has played with these Datsun hydraulic valves?

I believe the 'A' head is the same except for the lifters. It is easier to change to solid lifters/adjusters and put some mouse springs on the rockers. I believe that is all I need to do in order to run the solid cam in a P90A head. (Actually it will become a P90 head) Am I wrong about this? There must be some gearheads out their who have played with these heads????

I am having problems with my camshaft and lifters. It is a solid cam with hydraulic lifters. (They do not grind a cam for hydraulic lifters, so I am told) I know you cannot run this combo in other engines. Raver Motorsports built this head with this camshaft. Here is the problem: You can start the car and it will run OK. After it runs for about 5 minutes the lifters guit working. I believe they over pump and the engine has no compression. It will not restart until the lifters leak back down. When you check the compression, there is none! After it sets overnight, you have compression and it will start. Anyone else running the P90A head? What camshaft are you using? Anyone have any ideas on how to fix this head w/o changing to solid lifters?

I am having problems with my camshaft and lifters. It is a solid cam with hydraulic lifters. (They do not grind a cam for hydraulic lifters, so I am told) I know you cannot run this combo in other engines. Raver Motorsports built this head with this camshaft. Here is the problem: You can start the car and it will run OK. After it runs for about 5 minutes the lifters guit working. I believe they over pump and the engine has no compression. It will not restart until the lifters leak back down. When you check the compression, there is none! After it sets overnight, you have compression and it will start. Anyone else running the P90A head? What camshaft are you using? Anyone have any ideas on how to fix this head w/o changing to solid lifters?

I bought the 1000-pound 4-wheel stand from Harbour Freight. I got it on sale for $39.99. It worked very well as I moved the engine around the shop a lot. I cannot believe the price of these Chinese-built pieces. Everything is powder coated and plated. I guess you would have a nice stand if you had to use it every day. But for we hobbiests, Harbour Freight does a great job.

I finished my resto almost. I had my old crew member Steve from ZTherapy do my 2 1/2" exhaust system. (It looks great!) We started the new engine and it fired up the second we hit the starter. Steve tuned his new ZT carbs and I went for a short drive. It was at night and one of the bulbs was out on my dash. It just happened to be the OIL pressure gauge. We had 90# when we started the car. Anyway, I had driven the car about 3 miles and was on my way back when I noticed the valves started to 'clack'. When I got to the shop where there is an outside light, I noticed the oil gauge was down on pressure. I do not know what it was pumping but the lifters (P90A) were collapsing. I shut her down and we pushed her back into Steve's shop. We talked about the situation and decided it must be the oil pump. It had 90+ pressure and then the relief valve would kick in and stick open. We had a little pressure all of the time so I do not feel the crank/rod bearings were hurt. I ordered a new turbo pump and waited for the UPS truck to arrive. I got 2nd Day Air treatment on Friday and I installed the pump on Sat. BINGO! We now have 75# pressure and the engine runs great. I have an appointment with the alignment shop on Monday. All I need now is to have the HOOD fit properly (see Body and Paint forum) and I am finally done with this complete resto. 13 months of blood, sweat and tears! :knockedou