Lunati cam bearing journal problems

[femtnmax]

Here is the note I sent to Lunati, have not heard back from them yet. In the second photo the wear on the bearings was concentrated in the lower half of each bearing; basically the lifters were pushing the cam down into the bearings.

I have a small block Mopar 360 that had a Lunati H215 cam in it. I took the engine apart to change cylinder heads, and was going to install a Voodoo cam. Both of the cams mentioned had the cam journals belt sanded by Lunati, with the center 3 journals turned more than the end two. I say belt sanded because the oil holes in the cam journals have the edges rounded off which looks like the result of belt sanding. When I ordered this last Voodoo cam I asked that the cam journals NOT be turned as I wanted to preserve oil pressure, and I have no problems fitting a cam to cam bearings…But the voodoo cam also arrived with reduced journal diameters even though I specifically asked not to have this done. By the way a little scraping here and there as needed of cam bearings is usually all that is necessary for smooth rotation of a new cam fitted to new bearings
.
After less than 3000 miles the H215 cam I took out was wearing itself into the NEW cam bearings that were installed at the same time as the cam; with the center 3 bearings having obvious grooves worn into the bottoms. Cam journal to bearing clearance measured 0.005 inch at worst location. The end two bearings had tapered wear suggesting the cam was bending as it rotated. The crankshaft rod and main bearings showed NO signs of excessive wear with bearing clearances still within factory new specs, so the wear problem was focused at the cam.
It appeared the cam journals were too small compared to the bearings and were not supporting an oil film, rather the small journals were squeezing the oil out and allowing for metal to metal contact.
So I ordered a new cam from another mfgr, and it happened to have the same cam core as the voodoo cam and did not have any sanding of the cam journals…..the journals were 0.0005 to 0.0015 inch larger than the voodoo. When I test fitted the voodoo cam, its journals were so small the cam rode low in the NEW cam bearings and was trying to push the rear cam bearing out the back of the block as I slid the cam in place. With the “other” cam it slipped right in place after a minimum of fitting of the cam to new cam bearings.

Maybe your opinion is that belt sanding cam journals makes for quick easy drop in installation in engine blocks that have not had the cam bearing bores line bored. But reducing the cam journal diameters means they are already smaller than “stock” and thus the cam cannot be fitted to the cam bearings.

The problem I was having with cam bearing wear appears to be caused by too much oil clearance of the Lunati cam, and the replacement voodoo cam had similar “small” cam journals. These Lunati cams have become a waste of money and time. Lunati has a nice selection of cam lobes, but I cannot continue wasting time and money and risk snapping a cam in half while on the road. If you want a new in box single pattern voodoo cam I can send it to you, otherwise it is just a paper weight or tossed in the trash.

IMO Lunati should stop sanding cam journals, quit second guessing the bearing clearance, and leave it to the machine shop/builder to properly fit a cam to cam bearings.
Phil

 

[OwdKasd]

So were you showing low oil pressure while this wear was taking place? Wouldn't it make sense to install cam & Bearings as a matched set.

 

[crackedback]

I'll bet they got numerous complaint that those 3 journals were too tight when installed.

My guess is the cam tunnel in the block is on the tight side and oil canning the bearings. Pretty common issue. The real solution is to hone the cam tunnel to proper ID so the bearing fits correctly and doesn't crush too much.

Instead of solving the REAL issue, fitting the cam bearings correctly, they went and changed the OD spec on their cam journals... IMO the wrong way to do things.

 

[OwdKasd]

I doubt a manufacturer is going to ship parts purposely machined out of Spec to "anticipate" poor geometry of the engine they are going into.

 

[goldmember]

Here is the note I sent to Lunati, have not heard back from them yet. In the second photo the wear on the bearings was concentrated in the lower half of each bearing; basically the lifters were pushing the cam down into the bearings.

I have a small block Mopar 360 that had a Lunati H215 cam in it. I took the engine apart to change cylinder heads, and was going to install a Voodoo cam. Both of the cams mentioned had the cam journals belt sanded by Lunati, with the center 3 journals turned more than the end two. I say belt sanded because the oil holes in the cam journals have the edges rounded off which looks like the result of belt sanding. When I ordered this last Voodoo cam I asked that the cam journals NOT be turned as I wanted to preserve oil pressure, and I have no problems fitting a cam to cam bearings…But the voodoo cam also arrived with reduced journal diameters even though I specifically asked not to have this done. By the way a little scraping here and there as needed of cam bearings is usually all that is necessary for smooth rotation of a new cam fitted to new bearings
.
After less than 3000 miles the H215 cam I took out was wearing itself into the NEW cam bearings that were installed at the same time as the cam; with the center 3 bearings having obvious grooves worn into the bottoms. Cam journal to bearing clearance measured 0.005 inch at worst location. The end two bearings had tapered wear suggesting the cam was bending as it rotated. The crankshaft rod and main bearings showed NO signs of excessive wear with bearing clearances still within factory new specs, so the wear problem was focused at the cam.
It appeared the cam journals were too small compared to the bearings and were not supporting an oil film, rather the small journals were squeezing the oil out and allowing for metal to metal contact.
So I ordered a new cam from another mfgr, and it happened to have the same cam core as the voodoo cam and did not have any sanding of the cam journals…..the journals were 0.0005 to 0.0015 inch larger than the voodoo. When I test fitted the voodoo cam, its journals were so small the cam rode low in the NEW cam bearings and was trying to push the rear cam bearing out the back of the block as I slid the cam in place. With the “other” cam it slipped right in place after a minimum of fitting of the cam to new cam bearings.

Maybe your opinion is that belt sanding cam journals makes for quick easy drop in installation in engine blocks that have not had the cam bearing bores line bored. But reducing the cam journal diameters means they are already smaller than “stock” and thus the cam cannot be fitted to the cam bearings.

The problem I was having with cam bearing wear appears to be caused by too much oil clearance of the Lunati cam, and the replacement voodoo cam had similar “small” cam journals. These Lunati cams have become a waste of money and time. Lunati has a nice selection of cam lobes, but I cannot continue wasting time and money and risk snapping a cam in half while on the road. If you want a new in box single pattern voodoo cam I can send it to you, otherwise it is just a paper weight or tossed in the trash.

IMO Lunati should stop sanding cam journals, quit second guessing the bearing clearance, and leave it to the machine shop/builder to properly fit a cam to cam bearings.
Phil

The cam bearing bores should be checked first,most blocks need work in this area. Measuring bearing to cam clearance as your pic does not work as the cam bearing is compressed when installed in the block. I've only built 1 sb mopar(out of 30plus) that I had trouble and had to scrape bearing to fit.I'll never do that again as the problem is the block,not the cam. The clearance was too tight and caused the issue,NOT too loose as you state. Another problem is bent cams,yep,it's not so uncommon. I recently checked a brand new late model Hemi grind @ Bullet cams(the cam was from a very large cam company,but I won't state who) it was so far off the adcole about blew it's lid.LOL A few minutes getting it straightened out and all was good.

 

[femtnmax]

So were you showing low oil pressure while this wear was taking place? Wouldn't it make sense to install cam & Bearings as a matched set.

I did install the cam and new bearings together. I had a high volume oil pump in the engine at the time and was suprised how quickly the oil pressure dropped to zero each time the engine was shut down.
Good comments from the other responses about cam bearing bore diameters. As you say there is more to it than just the bearings. I always check cam rotation when installing new cams, so I know the fit was not too tight. For example the new voodoo cam with new bearings only touched two of the bearings (#2 & 5), the rest were floating free. When I installed the "other mfgr" replacement cam all journals touched all bearings.
We all have our techniques. I have always fitted cam journals to bearings as needed for at most slight resistance fit. I have worked as an ASE certified mechanic since 1978, built countless engines, and this is the first time I've had issues with cam/bearing fit.

 

[goldmember]

There should be no resistance when turning a cam by hand without the aid of anything but 2 fingers,resistance fit is not accurate. If I have any doubts I blue the bearings install the cam dry and rotate it a complete turn. Check the bearings and correct as you will. I haven't had this problem in a long time as I have the cam bearing bores checked and corrected. If the bore is undersize and you install a proper bearing the cam will struggle to fit or likely have too little clearance which is death to any plain bearing.

 

[OwdKasd]

I did install the cam and new bearings together. I had a high volume oil pump in the engine at the time and was suprised how quickly the oil pressure dropped to zero each time the engine was shut down.
Good comments from the other responses about cam bearing bore diameters. As you say there is more to it than just the bearings. I always check cam rotation when installing new cams, so I know the fit was not too tight. For example the new voodoo cam with new bearings only touched two of the bearings (#2 & 5), the rest were floating free. When I installed the "other mfgr" replacement cam all journals touched all bearings.
We all have our techniques. I have always fitted cam journals to bearings as needed for at most slight resistance fit. I have worked as an ASE certified mechanic since 1978, built countless engines, and this is the first time I've had issues with cam/bearing fit.

Sorry, I misunderstood. I thought you used 2 different cams with the same set of bearings. The Voodoo being the 2nd one. Otherwise the bearings should have been in tolerance with the cam. If they were in tolerance but then once installed in the block they created a problem, That would be a problem with the block. If they started out out of Spec then the situation was doomed from the get-go. FWIW, Each Journal should have had a corresponding Bearing. Each one is machined to fit perfectly. They are packaged in order and need to be installed in that very same order. Basic common Knowledge I know but Lunati Is going to need to verify that A. The bearings were installed in the correct positions and B. the Cam tunnel was "True". At this point the problem could be blamed on one of these thing or as stated above, a bent Cam Shaft.

 

[64 SRT8 Dart]

What did the original bearings look like before doing any kind of swap? Might be an indication if whether it's the block or the cam.
That's if you got it with the original stuff in it.

 

[femtnmax]

What did the original bearings look like before doing any kind of swap? Might be an indication if whether it's the block or the cam.
That's if you got it with the original stuff in it.

I wish I had, but the block came from a lineup sitting on the floor. I talked with Lunati, They said that they buff all their cam journals to chamfer the oil holes in the journals. Next week I'll compare journal diameter data to Lunatis data to the cam journals and phone Lunati back with the results.

 

[moper]

Like Goldmember said - it's pretty common for the cam bores to be off. I've also found bearings installed cocked slightly from the shop. That was so common I bought my own isntallation tool back in the 80s. I've had engines that needed nothing to turn with two fingers, and some that needed what I thought to be excessive trimming of one or two bearings to let the cam turn properly. Tht did not seem to produce any negative results. I'd rather a cam be loose than tight.