SleeperZ Posted October 4, 2011 Author Share Posted October 4, 2011 Yes, and don't listen to people who tell you that you can't swap cam towers. Just number the towers before you remove them, install them in the correct order and make sure the cam spins freely after they're torqued. I would regrind a stock cam. If you don't have one, email my bro-in-law at mat m AT m2differentials.com. He has probably 10 cams loose in his shed. I do have a stock cam, if I do decide to go this way. I'm curious though, the current cam was not a re-grind, and if it can be reliably repaired I could save quite a bit of money. Is there something about this cam you would not trust at this point? I have done a closer inspection, and I have to agree with JohnC and others there is a general problem of under-lubrication. Some of the lobes are blueing, and another is just starting to show signs of wear I think could turn into another flat lobe. I've never noticed an oil pressure problem, and I am running the ZXT auto oil pump, and none of the lobes seem particularly dry. But it's undeniable there is not enough oil getting to the lobes given the evidence. I don't know where to start in figuring out why. Worn bottom end bearings, not enough to notice a drop in pressure....it's a low miles factory re-build I found in a scrapyard and looked perfect when I had the head off. I don't know. Quote Link to comment Share on other sites More sharing options...
Zmanco Posted October 4, 2011 Share Posted October 4, 2011 I've never noticed an oil pressure problem, and I am running the ZXT auto oil pump, and none of the lobes seem particularly dry. But it's undeniable there is not enough oil getting to the lobes given the evidence. I don't know where to start in figuring out why. Worn bottom end bearings, not enough to notice a drop in pressure....it's a low miles factory re-build I found in a scrapyard and looked perfect when I had the head off. I don't know. Buy a cheapo mechanical oil pressure gauge and run it for a while. You may be surprised to find that you have lower oil pressure than you think, especially at higher revs. On my turbo the pump was more or less limited to around 45 psi IIRC. Adding a few washers brought the peak up to around 65 psi. That is at 180F oil temp with 10w30 synthetic above 5k rpm. The factory gauge is useless for checking this as it isn't accurate enough and responds too slowly. Jon Mortensen gave me this same advice and in the end I installed the oil pressure and temp gauges below the dash on the left and rotated them so their "normal" readings are just within view looking down. About the only time I pay attention to them is on the track. You might be surprised how hot the oil gets and you definitely want to be sure you have enough oil pressure then. Quote Link to comment Share on other sites More sharing options...
SleeperZ Posted October 4, 2011 Author Share Posted October 4, 2011 (edited) Actually I already run an Autometer mechanical oil pressure gauge. I can't say for sure what the value of the pressure was at higher RPMs, but I know it wasn't real close to zero, as I have it rotated so 45 to 60 psi is close to the top. And I do have oil temperature metered as well, from the sensor in the pan, and it typically goes to 220 or 230, maybe peaks to 250F or so.... However, maybe I should be running a higher viscosity oil. I don't know where I got the idea I should run 10W-30, but perhaps I could run the same oil as I run in my turbo diesels, Rotella 5W-40, fully synthetic and a bit thicker.... Edited October 4, 2011 by SleeperZ Quote Link to comment Share on other sites More sharing options...
JMortensen Posted October 4, 2011 Share Posted October 4, 2011 I don't like the Schneider cams because it seems to me that I have seen about 10x as many posts about Schneiders than about all other types of cams combined. No technical reason not to like them, just a gut thing from seeing so many with a lobe wiped. Quote Link to comment Share on other sites More sharing options...
Leon Posted October 4, 2011 Share Posted October 4, 2011 I don't know where I got the idea I should run 10W-30, but perhaps I could run the same oil as I run in my turbo diesels, Rotella 5W-40, fully synthetic and a bit thicker.... I don't know where you got it, but I got it from the FSM and that's what I run. This is not an oil viscosity issue. Quote Link to comment Share on other sites More sharing options...
SleeperZ Posted October 4, 2011 Author Share Posted October 4, 2011 This car is not a daily driver or operated in winter, purely track use. I'm thinking at high rpms and temperatures, 30 weight may not be cutting it; I'm just thinking out loud. Quote Link to comment Share on other sites More sharing options...
johnc Posted October 4, 2011 Share Posted October 4, 2011 Oil viscosity is not the issue. 10W-30 should be fine if enough oil is getting to the cam. The new synthetics are so much better the the oil available on the 1970s that viscosity is much less important. I ran 5W-30 Redline in my race engine. Quote Link to comment Share on other sites More sharing options...
macambra Posted October 7, 2011 Share Posted October 7, 2011 Although I had my P90 professionally built years ago, I have less than 60-70 hours on this cam. I was checking and adjusting the valve clearances, and this showed its ugly face. Schneider turbo cam (Stage II from MSA, Lift .460/.460 Duration 270/260.) Intake #2 only has a rocker-wide wipe on the high part of the lobe, currently about 1/32" deep, and the clearance was good. All the rest of the lobes seem fine. But one is all it takes. Any successful installs of this cam? I'm sure it's statistically possible to get a cam with 12 good lobes.... I have the same problem on the other end of the cam. I thought it was just me. How long have you had the cam? I bought mine earlier this year. Jan or Feb. I also purchased the matching springs. Quote Link to comment Share on other sites More sharing options...
GeeZ Posted October 8, 2011 Share Posted October 8, 2011 I had a Schneider go flat. Ran it for 2 years. Replaced with an Isky. Quote Link to comment Share on other sites More sharing options...
MidnightRider Posted October 8, 2011 Share Posted October 8, 2011 I'm running a Schneider Stage II with 180 miles on a rebuild, guess it's time to go synthetic with the first oil change. Quote Link to comment Share on other sites More sharing options...
boardkid280z Posted October 8, 2011 Share Posted October 8, 2011 I agree with the guys saying oil viscosity isn't an issue, unless you live in an extreme climate. But, I would make sure you use an oil that has a high enough zinc (ZDDP) content which is what older cars need. Metallurgies have changed, and newer cars have bearings, journals, cranks and cams that don't need zinc so oil manufacturers have drastically reduced the percentage of zinc in their oils, I think many have removed it completely. (lots of info out there about Zinc/ZDDP - like this) Our cars and many other older models especially with solid lifters/flat tappets seem to really need oils with higher zinc levels. I use Rotella 15W-40, it's a little thicker, but I live in Oklahama, so it's usually pretty hot here. I've got nothing against single weight though. I think most oils for diesel applications have higher zinc levels and most "special" oils that say they're performance/for racing or whatever have the zinc additives built in. [...] Hmm, well normally I would just recommend the Rotella since that's what I had always heard, but decided to do a little research to give you some other options. I knew Rotella had changed the formula in their 15W-40 to an updated CJ API rating vs the old CI. Turns out the 15W-40 has lower ppm than some would recommend, check out this thread: Zinc in oils Looks like 1200ppm is the minimum number to look for. And these are some of the oils they recommend. * SHELL ROTELLA SINGLE GRADE 30WT * CHEVRON DELO 400 LE 15W-40 (APPROVED BY MFG FOR GAS & DIESEL ENGINES) * CASTROL TRUCK & 4X4 SYN BLEND 15W-40 (NOT DIESEL OIL) * LUBRIPLATE GPO 15W-40 OIL (BUY ONLINE DIRECT FROM MFG) * PENNZOIL GT 25W-50 RACING OIL * VALVOLINE NSL/NOT STREET LEGAL 20W-50 (ORDER FROM NAPA/SUMMITT/JEGS) * ROYAL PURPLE FULL SYN 10W-30 * GM EOS (Engine Assembly Prelube) Or find an additive to use with any oil like: ZDDPlus Quote Link to comment Share on other sites More sharing options...
SleeperZ Posted October 18, 2011 Author Share Posted October 18, 2011 (edited) Thanks for that oil information, I should be able to put that to use. This weekend I turned the engine over with the valve cover off to check compression. It measures even across all cylinders with number 2 with the bad lobe about 5 psi lower than the rest. However, the compression numbers are uniformly low; typically I will get 110 to 115 psi, at least on a good stock L28ET with stock turbo cam. With this cam, I got 90 psi on all but number 2 at 85 psi. Oh well, I'm not tearing into the bottom end, it is what it is. While cranking the engine with the starter with the plugs removed, the oil flow on the cam seemed good, it didn't squirt but pooled out of the cam holes and number two intake did not seem lower than the rest. But the fact that the oil is quite dark (fresh change before the spring track event with no driving since) tells me the top end seriously overheated. Of course I have not yet checked the level, it's possible it's low and that would explain everything. I just wanted to confirm with those suggesting a spray bar in addition to internal cam oiling, all that is necessary is to swap the earlier cam towers and spraybar. Is there any machine work to do on the cam towers to retain the internal oiling, or are those passages already present? Thanks again, Nathan Edit: Checked the oil level, exactly one quart down on the stick. Could that, and a day on the track, cause starvation on the top end? Obviously it had something to do with it, but is it soley responsible? I'm still trying to make up my mind whether to add oil spray to the cam or to dig deeper for another issue ... Edited October 19, 2011 by SleeperZ Quote Link to comment Share on other sites More sharing options...
z-ya Posted October 19, 2011 Share Posted October 19, 2011 I think it is important to use a break in lube with a high zinc content, as well as an oil with high zinc levels. I'm using an Isky CWC grind on my race motor (almost .600 lift), and have had no issues with lubrication or lobe wear. I used Redline break in lube with Valvoline VR1 (high zinc) for initial break in. Then I ran another bottle of Redline break in lube with Brad Penn 20W50. It's just about ready for another oil change, and it will get more Brad Penn 20W50. The cam is internally oiled, and I'm also using a spray bar. Quote Link to comment Share on other sites More sharing options...
SleeperZ Posted October 19, 2011 Author Share Posted October 19, 2011 ... The cam is internally oiled, and I'm also using a spray bar. Is it as simple as swapping in the older style cam towers? Or are there internal oil passage mods to the older towers to allow the cam to be oiled internally? Are there orifices that need modification to adequately proportion the amount of oil to the spray bar versus the cam passages? Quote Link to comment Share on other sites More sharing options...
Tony D Posted October 20, 2011 Share Posted October 20, 2011 There were transition heads that simply had little block-off plates on the cam towers after going to an internally oiled cam. The supply is the same for both oiling methods, just how it is delivered is different. The grooves on the journals allow oil to move around to a drilled passage in the tower, and out to the spray bar. Block them off, and then it all stays in the towers. The internal cams have holes in those same grooves to go to the center of the cam and out to individual lobe holes. Most people will do the enlargement of the oiling galley when the head is off to allow more oil up there. I lost a turbo around a hard sweeping corner when the oil sloshed away from the pickup under boost. I could see low oil causing problems with pressure. Quote Link to comment Share on other sites More sharing options...
SleeperZ Posted October 20, 2011 Author Share Posted October 20, 2011 (edited) Thanks for all the information. I think I am going to trash this cam, and source a regrind using a good factory turbo cam, along with resurfacing rockers, all from my other stock P90A head (solid lifter). Hopefully I can get a set of lash pads and run the lift of the Isky or Delta cam people like for the L28ET, which is a bit higher than 0.460". At any rate it looks like if I need a little more, I could switch to Crane retainers or the Ford stem seals... And I think I will add the external oiling as well. I want the valve train to last a few seasons, I'm too old for too much of this crap. Edited October 20, 2011 by SleeperZ Quote Link to comment Share on other sites More sharing options...
Tony D Posted October 21, 2011 Share Posted October 21, 2011 "I'm too old for too much of this crap." I'm starting to say that more and more myself... Quote Link to comment Share on other sites More sharing options...
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