I asked for a 891 Cam...I received this Otto cam with gear and the lobes and lift are different from my marked 891 110 cam. The cam is marked CWC, C2-D2, D9-29, EP 125, PARTS, OTTO.

I am getting 1.4805 and 1.2285 on the lobe measurements .256 on average for lift at the lobe. The old cam varies but 1.38 to 1.39 mostly with some .264 lifts. So the base lobe is larger on the OTTO. Bob's book says .260 min lift for a 891.

What made me question the new cam was the lobe design...the OTTO has a very sharp lobe compared to the old 891 cam.

Has anyone had any experience with this cam? Advice welcomed. Thanks Jimmy.

All the OttO cams that Im aware of use a asymetrical lobe shape. Tis is because lifting the valve is tougher on things than when on its way back down to closed. The advantage of doing that a bit more of the duration can be used for opening and less for closing.

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Kevin Nash
Friday Harbor Washington
63 Spyder, Daily driver, EFI read about my project here: [corvaircenter.com]
first test start on EFI here:[www.youtube.com]
first official EFI boost test here:[www.youtube.com]
My new fan! [corvaircenter.com]
engine less 62 Spyder
Canadian 64 Monza Parts car
Test Start#2 [www.youtube.com]

Thanks Kevin...there are two more problems as I see it...the spacer washer next to the new timing gear is loose...you can spin it with your little finger...and the end of the cam is one and 1/8th diameter and by trial fitting, it rubs the oil pump/distributor housing. The two cams I have here that came out of orig engines...one a 140 889 cam and the other a 889 cam have 7/8 end to them.

I believe a number of people here have had the loose washer when they had the gear pressed on by the likely company you did not name the cam came from. That company supported the loose washer as appropriate. My assumption is the gear is pressed on and then the pressure released. When the gear/washer cool the parts shrink and the clearance is created. Many here who press their gears leave the pressure on until the parts have completely cooled.

I would disagree with the loose washer on four principles. One, there is (now) a steel on steel movement with the inner diameter of the washer and the cam. Two, whatever looseness there is in the cam/thrust washer adds to the inherent camshaft end play already present in the washer groove. Three, this was brought up by someone else - the washer spins less, if not at all, and does not help to circulate the oil in the thrust groove. Four, without the gear tight to the washer it would seem to potentially allow the gear to wobble more readily should it ever experience looseness via heat or other causes. That said others stated they have had no issues running a loose washer.

Thank you wittsend...I will PM you as to who it was. I was told they sell all their cams with thrust washers that spin...I do not see any clearance but my little finger rotates the thrust washer with no problem. I was also told that they do not cut down the oil pump/dist end of the cam as someone might want one for airplane use. I was told to grind some off the oil pump housing or cam to fix the larger end on their cams. Theirs...1 and 1/8 inch diameter...my old 889 and 891 cam has a 7/8 end and both thrust washers are not moveable from the factory.60 years of use and still tight. Tells me volumes. I was told some of the early models of oil pump housings were thicker than the newer housings...mine is a 1964 110. I was told they would press it on harder if I send it back...Bob Helts book says that is a NO-NO as the gear will be loosing up. I think I can get my $$$ back but then will have to deal with someone else. Again, thank you and I agree with your 4 reasons to have the thrust tight I think that the washer will be now cutting into the cam I think or wearing the T washer.

red monza Wrote:
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> Thank you wittsend...I will PM you as to who it was. I was told they sell all their cams with thrust washers that spin...I do not see any clearance but my little finger rotates the thrust washer with no problem. I was also told that they do not cut down the oil pump/dist end of the cam as someone might want one for airplane use. I was told to grind some off the oil pump housing or cam to fix the larger end on their cams. Theirs...1 and 1/8 inch diameter...my old 889 and 891 cam has a 7/8 end and both thrust washers are not moveable from the factory.60 years of use and still tight. Tells me volumes. I was told some of the early models of oil pump housings were thicker than the newer housings...mine is a 1964 110. I was told they would press it on harder if I send it back...Bob Helts book says that is a NO-NO as the gear will be loosing up. I think I can get my $$$ back but then will have to deal with someone else. Again, thank you and I agree with your 4 reasons to have the thrust tight I think that the washer will be now cutting into the cam I think or wearing the T washer.

i had an TB-10 that I bought from Clarks years ago, and had them install the failsafe gear. The thrust washer was installed too loose for my taste. I pressed it on tighter at work and had zero problems with the cam gear loosening up. Its one thing to cold press the gear another .001-.002 to tighten the thrust washer and another to cold press the gear all the way on that way!! I looked up the section in Bob Helts book about pressing the gear on, and although it clearly states to press the gear on hot, and the cam cold, he is reffering to a stock style gear (not a failsafe gear) and most definitely not talking about moving the gear another .001-.002" cold. Not a big deal with a failsafe gear!

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Kevin Nash
Friday Harbor Washington
63 Spyder, Daily driver, EFI read about my project here: [corvaircenter.com]
first test start on EFI here:[www.youtube.com]
first official EFI boost test here:[www.youtube.com]
My new fan! [corvaircenter.com]
engine less 62 Spyder
Canadian 64 Monza Parts car
Test Start#2 [www.youtube.com]

If you're in contact with whoever sold you the cam what Otto cam do they say it is? Although if they'll try to slip you a different cam I'm not sure I'd believe them.
What kind of a cam gear is it? Some folks said a year or two ago that there's one similar to a Failsafe that it's good to stay away from. I forget what was printed on it for identification.
I would run a thrust washer that spins before I'd redo a press fit.
The diameter explanation on the end sounds like hokum. Just how do they expect you to fix it yourself?
There's some Otto cams that were better back in the day but there's been some problems with consistency since the true Otto days. For all I know the problems have been rectified, I certainly hope so.
If I was in your shoes I'd probably have to check cam timing on all 9 lobes but then I have the capability.
I'd be interested in where you got it in a PM.

Jim Brandberg
Isanti, MN
CorvairRepair.com

Put some red loctite front and back. It should hold since it is good for 600 f. That's better than anything else you can do.

As long as total end play isn't more than .004", it doesn't matter if the thrust washer spins.

Thanks Layton and Richard. I decided to go with another cam from another Corvair person/supplier...suppose to be shipped Tuesday to me. It is a 260 cam vs the 891 cam with a tight thrust washer and smaller end to clear the oil pump/dist housing. All of this has slowed me down weeks from listing this 64 110/4 speed convertible on BAT.

There seems to be so many inconsistencies with cams these days.
If this one is an Otto that has been reground to be a 891 I have to wonder how it still has a big base circle.
It could be just fine and maybe even better than a 891. If I had it I would maybe take the time to check the timing on all 9 lobes.
I wonder if the days of just checking #1 and figuring the cam grinder knows what they're doing are over. I say this because of a PM I received a few years ago from a fellow who found #5 and 6 to be different from 1,2,3 and 4 with the result of 2 damaged irreplaceable race pistons from detonation.

Jim Brandberg
Isanti, MN
CorvairRepair.com