BB mopar valve train harmonics?

[gregsdart]

I have a 15/1 compression alky injected big block that I shift at 7450 (data logger info) equipped with Jessel 1.7 rockers PAC 1228 springs, ti retainers. Springs are in at 2.035 cb is 1.100 . 320 on the seat and 825 max lift. Max net lift with checking springs was .834. Cam is from mike jones. Pushrods are Manton 7/16 straight wall by 9.760 long. I put supposedly good slightly used rockers on it and have a failure already. The guy I got them from has a great reputation and the needle bearings looked good when I installed them. The rockers have a .800 offset and hurt the pushrod side bearing, (two 1/2 inch wide bearings per rocker) and the damage is on the inner side. Broken cage and galled shaft after about 20 runs.
Any thoughts on possible causes?

[Walter R. Malik]

I have a 15/1 compression alky injected big block that I shift at 7450 (data logger info) equipped with Jessel 1.7 rockers PAC 1228 springs, ti retainers. Springs are in at 2.035 cb is 1.100 . 320 on the seat and 825 max lift. Max net lift with checking springs was .834. Cam is from mike jones. Pushrods are Manton 7/16 straight wall by 9.760 long. I put supposedly good slightly used rockers on it and have a failure already. The guy I got them from has a great reputation and the needle bearings looked good when I installed them. The rockers have a .800 offset and hurt the pushrod side bearing, (two 1/2 inch wide bearings per rocker) and the damage is on the inner side. Broken cage and galled shaft after about 20 runs.
Any thoughts on possible causes?

Maybe that bearing just reached its limit or there was not enough oil present in it or the oil there had gotten to hot for some reason.

This is all presuming that the shaft surface hardening did not give-up.

[panic]

Maybe that bearing just reached its limit

Needle journal bearing is one of those ideas that sounds good... until you remember that a needle has very little load bearing surface vs. a bushing.
The fact that Jesel makes it doesn't mean it's a good idea.

[wyrmrider]

try
www.rockerarms.com/
and see if they have a fix
I've done a wider bearing on one side and narrower on the other
perhaps just brass bush them>
heat treated shafts?
with brass bushing you can save your shafts with a triple plate hard chrome

[Powertrip]

What makes you think it was harmonics that caused this? Is your data logger showing a "hole" in your powerband? It would seem you are using good parts at not a lot of RPM, you can never tell how much life is left in used parts.

[Geoff2]

[1] Were the failures near the front of the engine?
[2] Did you use a restrictor in the supply to the rockers?

[gregsdart]

Slowly getting this thing back together. Jesel says the trouble I had with hurting pushrods (lash got way big) was probably the cause. Poor oiling took out the pushrods. I am going to run pushrod oiling to take care of any trouble with pushrods. If there was an easy way to pressure oil a paired rocker system, I would be looking into some bushings, rather than needle bearings. If they will work in a roller lifter, they ought to survive just fine in a rocker! I have been fixing hurt rockers WAY too long.

[andyf]

The 0.800 offset rocker arms were brand new, never used so I don't think that is the problem. I had problems with the Jesel setup on my Indy heads until I went pushrod oiling. I had plenty of people tell me that pushrod oiling wasn't necessary but for whatever reason my stuff would burn the pushrods until I went pushod oiling. After pushrod oiling everything looks brand new.

[gregsdart]

With my 1.55 rockers it appeared to be side thrust hammering the needle bearings, breaking them. I now have the rocker body's running against bronze washers .Hopefully next season will be a LOT more trouble free!!

[wyrmrider]

I've run oil through the pushrods on BBM,SBM, Hemi, FEFords etc for years- you are on the right track
if you have the option use the larger cups and adjusters

[statsystems]

The 0.800 offset rocker arms were brand new, never used so I don't think that is the problem. I had problems with the Jesel setup on my Indy heads until I went pushrod oiling. I had plenty of people tell me that pushrod oiling wasn't necessary but for whatever reason my stuff would burn the pushrods until I went pushod oiling. After pushrod oiling everything looks brand new.

They will never oil right if you don't correct the timing of the oil hole in the shaft to the oil hole in the rocker.


That's why I quit using HS rockers. They will argue that the bearings leave a passage to feed the adjuster but they are full of shit.


The oil hole in the shaft must line up with the oil feed hole in the shaft, when the valve is on the seat or it will eat pushrods and adjusters, regardless of how many times HS says it don't matter.

[A_VAS]

related question (somewhat)...when you guys are switching to pushrod oiling...on a shaft mount mopar rocker setup...do you restrict the oil coming up to the head passage (shaft feed) in any way? Or just leave that alone, and add the pushrod with normal holes in them to send oil to the rocker adjuster? I'm wondering if I don't restrict, will the head get flooded and try to push oil out of any orifice the valve covers have (and starve the bottom end possibly)..or if I'm over thinking it.
thanks

[gregsdart]

A lot depends on how much oil gets sent up the pushrods. In my case I have a bushed lifter bore block with .060 holes drilled cross ways from the lifter.galley. the lifters have two holes that appeared to be about.080 diameter, positioned 90 degrees away from the feed hole. The lifters have .001+ clearance, and the amount of oil going up through the pushrods that had .090 (about) holes was WAY more than I thought would flow through that route. The motor wouldn't make more than 45 psi oil pressure at high rpm. I had the pushrods restricted to .030 and that helped a lot, but there is still a lot of oil going up there. Pressure is now 75 psi hot at high rpm with very warm oil.
I run Jesel rockers, so there are no shafts like stock systems.

[Strange Magic]

Sounds like you got your oil pressure handled. I would highly suggest to dump your spring pressure down to around 280-290 max. That is way more than enough to handle your situation. On another note, just out of curiosity, have you taken a cranking compression test on that engine? I'd like to hear more about this engine, bore/stroke, cam, valve size ect..

[gregsdart]

Strange, this motor is a Mopar Megablock 4.500 bore, 4.15 stroke. Heads are 440-1 ported by RJ in Iowa. Heads have been cut to 62 cc allowing a very modest dome of about .080 to get to 15.1/1 compression. Rings are .043 top, .043 second, 3/16 low tension oil. Pistons are Cp. No coatings were used in this build. The crank is from Crower, with center counter weights, which eliminated cap walk when I went to it. Crank was not knife edged, which I should have ordered done. After the last rering the cranking compression was average 208 psi, after a warmup, with one cylinder showing 197 psi. This block did suffer some rust from many seasons on alky. The motor was originally built in 2003. A couple of spots in two or three cylinders had some signs of those spots still there after the rehone. next time around it will probably be time for new pistons. The induction is an Indy 3X single plain topped with a 2200 cfm Termintor alky injection system. The cam has changed over the years, starting with an Isky RR735 with 280/288/110 duration, and .761 gross intake lift. That cam had 197 at .200 lifter lift for duration. I tried a new grind in 2005, going to 283/296/112 custom grind with a gross .775 intake lift and 203 degrees at .200 duration on the intake lobes. The current cam is from Mike Jones, with similar at .050 numbers as the second cam, but a lot more duration at .100 lifter lift and gross lift of .875 with higher ratio rockers that went in with it. For grins I did a comparison of the second cams intake lobe duration AT the valve, rather than the lifter versus the new cam from Mike. The Jones cam showed as much as seventeen degrees more duration at .100 VALVE lift, when lashed.
On the spring pressure, the window for installed height is very narrow, with +.100 retainers and +.050 locks used to be able to get up to 2.035 to 2.050 installed height, leaving a decent .090 margin to coil bind.
I ruun this motor up to 7500 rpm through the traps, and with other tires has seen 7800 in the lights. With 2.300 stainless valves for intakes and a VERY heavy valve train, I figure it is better to err on the high side on the installed pressure, along with being close enough to coilbind to help stabilize the springs at high rpm.
This motor originally dynoed at 847 hp at 6900 rpm in 2003, with some performance improvements at the track from tuning and upgrading the oil pan system. It ran a best of 8.779 at 153 mph with a poor 60 ft of 1.28 back in 2004. That was at 3,000 lb race weight. This was on radial slicks, and I did see 60 fts of 1.250 with those tires later. Between poor shocks and a converter not optimized, I figure there was more there, just didn't find time to go after it.