FE Power Forums
FE Power Forums => FE Technical Forum => Topic started by: Diogenes on November 19, 2023, 08:41:35 PM
-
Has anyone used these before?
https://www.summitracing.com/parts/PQX-9539008
I have stock adjustable rockers that are in need of some proper adjustment, the kind that will stay in place. I just want to confirm these will be the correct thread and part, and that they are good quality.
Thanks in advance
-
Production rockers used a screw with an interference fit. When the screw/rocker wore out the interference, it was possible to buy screws with a bit more interference. When those wore out, it was necessary to get a new rocker/screw combination. I guess what you're showing might work, but be aware that the top of the rocker arm has a bit of spine/off-parallel surface that'll need to be finished at 90 degrees to the screw hole. Long ago, Brother Lon and I had the tool-room at T&C Livonia nake up some lock-nuts from Hex bar stock. They were made to fit the existing threads on the production screws. The nuts need to be thin to go into the existing space at the top of the screw. We used a belt sander to flatten the rocker arm surface.
KS
-
First comment, nothing PRW should go in your engine, especially the adjusters that have been known to break in their intended rockers! Stay away
Second, I have a buddy in VA that has used Harland Sharp rocker adjusters and locks with factory rockers, but I have not seen or felt how they fit, he said he was successful though
Ken's comments above are accurate as well, just need to see what that top edge and the threads feel like. It'd be easy enough to get a 7/16-20 bolt to evaluate thread engagement, then determine if you need to file or machine the nut mating surface
-
Those will work. Be aware they are Chinese. But, they are the correct basic thread of 7/16" x 20 . Like Cammerfe stated you will need to maybe file the pad flat/90'. Then most important run a 7/16" x 20 tap through each rocker to chase out the interference thread. Or do these steps and buy a better set.
Doug aka pumpbldr
Precision Oil Pumps
-
It sounds like it would just be best to replace the rocker assemblies entirely. Given that it is likely that most of the adjustable rockers I've looked at are not very good quality, what is the most economical replacement, with acceptable quality of course. High dollar rockers are definitely not in the budget at the moment, but it appears that high dollar rockers are all that is available.
The Harland Sharp adjusters look to run a little over $200, seems best to just put that towards new assemblies.
-
For those interested, Pioneer Automotive's Engine Parts Catalog lists part numbers for stock replacement adjusters, RM-589, and they also list an adjuster with a .003 oversize to compensate for worn interference threads on the rocker arms--RM-595. I have yet to find availability on these parts, but that is just with an initial web search.
-
For those interested, Pioneer Automotive's Engine Parts Catalog lists part numbers for stock replacement adjusters, RM-589, and they also list an adjuster with a .003 oversize to compensate for worn interference threads on the rocker arms--RM-595. I have yet to find availability on these parts, but that is just with an initial web search.
I would sure like to find some more of those .003" oversize FE rocker adjusting screws, if anybody ever finds them available somewhere. I still have some , but could always use more. I bought mine from Ford Power Parts , and they work great, good way to save factory iron adjustable rocker arms, that are otherwise fine.
-
Will the rocker adjuster screws for a 368 Lincoln or 312 Y block work ??
Ricky.
-
Will the rocker adjuster screws for a 368 Lincoln or 312 Y block work ??
Yes!
Back in the old days, when the interference tread studs became too loose, we used to go to the junk yards and scab the adjusting studs & nuts from the "Y"-blocks; but often the nuts interfered with the relief on the top of the rocker, so some "fitting" was necessary. And if I recall correctly they also were a little on the short side, so there wasn't a great latitude in adjustment travel, so the set needed to be right. :)
Scott.
-
Something I've considered, though am weary of, is the fact that the adjuster resembles a set screw. I have found a source for various length set screws (allowing for a bit more length to incorporate jam nuts) with a variety of hardness, and with what they are terming an "oval tip". My concerns regard both hardness and shape of the "oval tip", as it is risky putting such unknowns in an engine. Best not to mess with unknown wear characteristics to save a few bucks--OK, more than just "a few" bucks, but still not worth the risk.
Trend Products also seems to manufacture adjusters, but I've yet to locate a source or pricing. Looks like they are out of Warren, MI, and have a place down in NC. It appears they manufacture their own products, but not verified that.
...just brainstorming, trying to solve a problem.