Do any of you run Dove Rockers and have you had any problems with them? I seem to remember a thread about broken push rods and Dove rockers being mentioned. Was it ever decided what the problem was/is?



I did a search but could not find what I was looking for.



Thanks,

BOB

Usually the pushrod problem comes from using p/r's that are too long. The Doves need a p/r that is about .175" shorter than stock. If long p/r's are used the cup end hits the bottom of the rocker and bends the p/r as it moves through its travel, eventually breaks.

There are no bushings in the Doves, they ride on the aluminum. This is okay if oiling is good. Zero life if oiling is not.

Ted uses more of them than I do so his opinion regarding street use would be the one to go with.

http://ford-y-block.com 

20 miles east of San Diego, 20 miles north of Mexico

I've been running them for a while now. I'm also the one who had the issue with a broken pushrod. The evidence pointed to Chuck riding in my truck. Keep him away from your vehicle and everything will be ok.



It looked like the cause was a defective pushrod. Since replacing the pushrods, I've had no problems.


Lawrenceville, GA

As Charlie brings up, that prior conversation ended with the cup in the pushrods being too small. Here’s the link

http://forums.y-blocksforever.com/Topic26796-3-1.aspx

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Here are some general guidelines when using aluminum rockers on the Y. Insure that the rockers have adequate shaft to rocker clearance; I target for 0.004” clearance.

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Restrict the oil flow at the overflow tubes so that the shafts are being pressurized. I don’t completely pinch off the overflow tubes which allows some residual oil gets through and insures that the shafts are purged of air and still allows some oil to get to the trough that feeds the timing gears. There are other alternatives or options in how to accomplish this so just do a search on the site for ‘oiling mods’.

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Slotting the oil holes in the rocker shaft is also needed to insure that the groove in each rocker aligns with the shaft oil holes. Here’s a link to the thread showing a picture of the shaft modification.

http://forums.y-blocksforever.com/Topic6985-3-1.aspx

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Running too short a pushrod with Dove rockers can cause some rubbing of the pushrod at the bottom of the head in the pushrod hole so needs to be watched out for also. Using a pushrod that keeps the rocker adjuster at a mid position will also keep the rocker close to its advertised 1.6:1 ratio. A shorter pushrod reduces the ratio while a longer pushrod increases the ratio. Here’s a link to the past YBM article showing what happens with the rocker ratio as the pushrod length is changed.

http://www.eatonbalancing.com/blog/2007/12/10/altering-rocker-arm-ratio-by-varying-the-length-of-the-pushrods/

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Using a 5/16” diameter pushrod instead of a 3/8” diameter pushrod is a plus in these cases. This just gives more clearance in the pushrod holes in the heads. As John mentions, too deep a cup in the pushrod is also a problem but is easily rectified if spotted during assembly. This same issue crops up on the FE’s as well.

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Rocker arm geometry also plays into how the pushrods fit. If the heads have been refitted with longer than stock valves, then the rocker shaft assemblies need to be raised accordingly so that an ideal valve train geometry is maintained. Pushrod issues come to the forefront when the rocker shafts are sitting too low on the heads. If the geometry is not correct, then the advertised valve lift will not be achieved. Adjust the geometry (rocker assy height) first and then adjust the pushrod length accordingly. This goes for any shaft mounted rocker arm setup and not just roller rockers.

Lorena, Texas (South of Waco)

Thanks guys for the responses. I don't know if I really need them, I am planning on building a reasonably stout 312" for my next project. But what I really like is the roller tip for adjusting the clearance (looking long term).



Charlie, I'm assuming you are running them in your truck, on the street? That's what I am planning in my '55 Customline.



Thanks again,

BOB

Yep, driven daily.


Lawrenceville, GA