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Old 05-30-2004, 06:27 PM
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misaligned roller rockers?

I am always still looking for a knocking noise on my 383 stroker. I am focussing on the brodix heads now since they are really the only thing that had changed since when that same engine was just fine. The heads have been redone this winter..nothing major mainly eight new exhaust guide valves and teflon seals on all 16 valves.

While the heads at Brodix I know the guideplates been removed for cleaning up the heads and reinstalled by them before sending me back the heads. I know they got (guideplates) removed and reinstalled because I had one pushrod that wouldn't fit neither align itself and I had to slack and relocate the guideplate to allow the pushrod fitting. But I didn't pay too much attention to the other guideplates as they were allowing a free moving pushrod...

But looking carefully at some rockers today (crane full rockers) I can see some that are barely clearing their own edges from the valves tips....I mean the rocker's roller seem to be that much of-center that when actually moving the side of the rocker edge rather its roller tip could be contacting the valve stem tip...I guess this is caused by the guideplates not beeing at their right on position?!

I am a green on that subject of roller alignement so could somebody tell me what I should be looking for and how to achieve the really optimum of roller centering? Should they all be right on center/center or normal is it to see some of center results?

I will later take off those really limits rockers to check for any evidence of contacting with the edges ...I guess such a case could cause some knocking also?

Keeping on my research I appreciate all of the help and knowledge encountered here.

thanks, Ronald.

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Old 05-30-2004, 08:50 PM
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Ronald, I'm not sure I was able to follow youi through the description of your Crane roller tip and pushrod end innerface. I had ordered Crane roller rockers for my 383 and followed their instructions for proper install. First, I was going to have to do some clearancing of the roller to prevent spring bind, which was covered in their instructions. Second they were pretty fat and made things very close. After placing four of them on one head and saw all the potential problems, I sent them back and purchased Comp Cams Pro Magnums which are made from steel and were much smaller and did not require clearancing. I checked the push rod lengths, and in both cases, the OEM push rods were too long.

Trees
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Old 05-30-2004, 09:14 PM
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Now that I have taken out the rockers I can see that even if not perfectly centered on the valves tips the rollers could not contact the valves tips with anything else than some part of the roller...still I guess the ideal positionning for the roller is having its center in line with the center of the valve stem rather right on its edge...basically that was and still is my questionning.

But now I can see the guideplates were not ideally positionned having some pushrods incredibly close to the heads material...so close that eventual rubbing could occur...so I'll fix this moving the guides a bit.

In my case clearances between the rockers themselves isn't a problem. Your steel comp cam I believe are recognized as a superior product to aluminium ones...

regards, Ronald.
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Old 05-31-2004, 05:23 AM
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Most of the larger Brodix use offset rockers on the intakes to clear the large intake runners on the SBC, i don't remember the numbers. You can check on their site.
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Old 05-31-2004, 06:43 AM
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Now I think I understand what you are talking about. Your roller tip is not in the center of the valve stem which means your push rods ar not the correct length. Also, from what you described, the center line of the roller tip is very close to the edge of the valve stem. This is a no-no so you need to get a push rod checker tool and determine the length you need to get the tip in the center. I had to get 0.25 shorter than OEM with my roller rockers (Edelbrock Etec 200 heads) Also, is there not some room for adjustment on your guide plates that will give you better clearance/alignment?

Trees

I have revisited your posts and need to add more info on how to determine where your roller is contacting the valve tip. With the rocker off or ****ed out of the way, use a felt tip pen to cover the valve tip. Install and adjust the valve, then turn the crank enough that the valve goes through one complete cycle. You will notice there is some roller movement across the valve stem. Then remove the rocker and you should be able to see where the center of the pattern is from the marking on the valve tip. I usually repeat this on two intake and two exhaust valves to verify a repeatable pattern. The push rod checker tool can be purchased from Sumitt racing for about $17 or you can make your own by cutting about an inch section out of an old push rod and threading inside of the hollow stem, inserting a two inch stud with a couple of lock nuts. Once you have your tool and have adjusted it to the length to put your roller pattern in the center of the valve tip, you need a good caliper to give you the exact length, or you can take your tool to a machine shop and get them give you a precise measurement..

If any of this has confused you, go to a local engine building shop and get them to go thru the procedure with you. I'm sure they will be glad to help.

Trees

Last edited by trees; 05-31-2004 at 07:02 AM.
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Old 05-31-2004, 06:17 PM
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trees,

Thanks so much...there is a lot to learn from your last post. Unfortunately I'll be out to the sea (fishing lobsters here!) for few days and just don't have time to check this right now but I'll be back to it soon and see if I can get those rockers straight on center...yes I can play a bit with the guideplates but don't know if its enough play to center those!

Ronald.
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