M.Rad.

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About M.Rad.

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    Junior Member
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core_pfieldgroups_99

  • Location
    Central TX
  • Interests
    Cars, Motorcycles, Guns, Horses
  • Occupation
    Radiation Control Specialist

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  1. Hi everyone, thanks to all who offered advice and encouragement in my previous post about rocker arm selection. Now that I have some quality rocker arms (Scorpion), I also have another question. Do I need to surface the tops of my rocker arm studs to a level finish in order for the poly lock set screws to hold properly? The reason I ask is that I vaguely remember reading somewhere about set screws coming loose because the studs were uneven at the top. Is this a valid concern? When I installed the rockers to run a test pattern on the valve tips, the set screws seemed to lock pretty well. Of course that was without the influence of a running engine... I have access to a tool and die grinding machine if needed. Once again, any advice is appreciated! Regards, M.R.
  2. Update: I received my Scorpion brand roller rockers yesterday, and after trial fitting several of them, I am happy to report that they fit well and work with the stock length pushrods. There is no interference, the sweep pattern is centered and acceptably narrow. Now I just have to adjust the guide plates and the valve train should be done. Whew! Thanks again to all who took interest and gave advice and support! Regards, M.R.
  3. Tinman- I agree, it was good practice! I read through all the links you sent and as many others as I could find that were relevant on this site, as well as a couple others.I also spent considerable time observing, measuring and performing some small experiments with the pieces and equipment that I had. It gave me an expanded understanding of what was happening and the relationship between the parts. Combined with the generous advice of my fellow forum members I feel I have advanced a fair distance in my skill. I tried to include some pics, but I guess they're too large. I'll work on it again later. Regards, M.R.
  4. Ok guys- thanks for all the replies and assistance! From the benefit of your experience, I have decided to bite the bullet and get the Scorpion stud mount rockers. They are going to be SO over-kill for this cam, but since it has the pedestals cut I don't have much choice (I bought the engine incomplete with no rocker arms so I don't have the sleds for adjustable valve train). Tinman put the final nail in the coffin when he told me of his experience with the ball pivot allowing the rocker to roll over. I think I could have made the Pro Comps work with the shorter pushrods and I could live with wide sweep patterns, or even off-center patterns, but the prospect of having a rocker lay over on a long trip- that I can't accept. Reliability is paramount since it's going in the wife's daily driver. Now my concern is valve cover clearance. I'm using the factory finned aluminum covers. Has anyone experienced any interference issues with the Scorpion rockers? The drip rails were missing from the covers already so that won't be an issue. Regards, M.R.
  5. That's it! I'm done!! I'll just have to eat these, and buy some better rockers. Now comes the puzzle- which ones? Are these any good: Comp Cams High Energy #17045? An education indeed my friends! How come they never show these kinds of problems in the magazine articles or internet videos? Regards, M.R.
  6. Hi Boss34ford, both the solid checking lifter and my hyd. lifters measure 1.991" length. The solid has 0.360" from top of the lifter to the pushrod seat. The hyd. has 0.300" from the top of thelifter to the pushrod seat. After compressing the plunger .060" they would equal out. The valve stems are standard height, set to 1.820" from head to retainer. The only other change is the rocker arm itself, where I believe the problem is originating. I don't know any place to get a different rocker arm to try, unless I buy just one. But which one? I guess I'll start a new thread and ask others what rocker arm / pushrod they are using. Regards, M.R.
  7. I spent yesterday evening checking the pattern on the rest of the valves, and they look relatively even with the 8.040 length pushrod. The stock length is just too close to the edge for comfort, even given the narrower contact patch. I also checked with some plain non- roller Chevy Big Block rockers and the sweep scrubbed the entire of the valve tip. I also checked the valve tips on a set of '72 CJ heads that I have. Those used the standard Ford bolt-down rockers, and the scrub pattern covered the entire valve tip there too (although that may be due to the valve rotating?). Compared to the stock Ford pattern, my short pushrod setup is adequate. And since the stock setup can last quite a long time, especially with a conservative cam like mine, this should be equivalent. I thought about trying different/ higher quality / more expensive rockers, but those would probably require custom length pushrods too, adding to the cost. And then there is the possibility of other un-forseen issues with the new rockers... So, it looks like the setup is going to be the Pro Comp roller tip rockers with short (8.050) Chebby pushrods. The engine will be run-in on a stand, so I will be able to examine the valve train easily and determine if any problems have surfaced. On a side note- after reading a lot about rockers over the last few days, and performing my own "experiments", I am puzzled why rocker arms are made with roller tips anyway? It seems that the rollers don't actually roll across the valve, but rather slide just like a "shoe" type.. So really, I'm not gaining anything with the new design other than the possibly reduced friction of the pivot ball vs Ford's sled fulcrum and a narrower contact patch. Seems like a lot of trouble for little if any gain.. Sigh... Regards, M.R
  8. Update: I did some more mock-up and checking tonight using the stock length push rods. While the roller tip looks to be very close to the outboard edge, it moves inboard when the valve is lifted. Also, while the the sweep pattern is near the outer third of the valve tip it is narrower by about half than when it was centered using the shorter push rod. From the reading I've done on this board and what tinman recommended, I have concluded that the lesser of the two evils is to have as narrow a pattern as possible at a reasonable distance from the edge of the valve tip. This will allow the valve to be driven down relatively square, with a minimum side loading due to scrub, as well as losing the least amount of lift to back-and-forth travel of the rocker tip. Does this sound about right? Regards, M.R.
  9. The more I know, the less I understand... Ok, after reading through your links (thank you), I get the impression that I may have been chasing the wrong objective. Instead of looking for the most centered sweep pattern, I should try for the NARROWEST pattern within a reasonable distance from the edge of the valve? Objectives being the least amount of side loading, and the least conversion of lift to horizontal movement. Is that close to correct? The rest of the Mid Lift stuff seems kind of moot, since I don't have the ability to adjust things like roller tip height, pushrod cup location or distance between the stud center-line and the aforementioned rocker arm points. BTW, is there a "perfect" rocker arm for the Cleveland that addresses all the geometry problems? Regards, M.R.
  10. Hi guys, thanks for the responses. Roo- I MAY have someone to borrow a rocker from in the next couple days. I'll post what I find. Tinman- It looked like it would have slid off the outboard side, but I didn't cycle it... Many thanks for the push rod chart, it's amazing!! Did you put that together? It looks like the '79-'81 Pontiac 301 pushrods are a perfect fit! Assuming I can get an acceptable sweep across the vale tip, is there anything wrong with proceeding like that (using the Pontiac pieces)? Or is it the wrong way to do this? I saw no evidence of other problems like interference between the rocker and stud or retainer, and not even close to coil bind, etc. Regards, M.R.
  11. Hi Guys, I am attempting to set up my valve train and have run into some problems. Here is a run-down of my components: 1970 4V heads with machined pedestals, 7/16 studs and guide plates; S.S. valves, single groove retainers; single spring with damper (97lb closed/270lb open. Installed at 1.820"); Melling C.J. repro. cam (207*/221*@.050-.481"/.489"), and most importantly- Pro Comp roller tip pivot ball rockers (yes, I have read the threads discussing the difference between BBC and Ford rocker design). Yesterday I installed the rockers on cyl#1(TDC compression) using a solid lifter, stock length hardened push rod ( 8.410" ), and tightened the rocker down to .003" lash (just to make sure nothing was binding). When I checked the roller-to-valve stem position I found that the roller was sitting at the far outboard (exhaust side) of the valve tip. I removed the stock length push rod and installed an adjustable push rod. I shortened it several times until the tip travel pattern was centered on the valve stem (far inboard at base circle, far outboard at full lift). At this point the push rod measured 8.060". That's .35" shorter than stock!! and the pattern on the valve stem tip was very wide, leaving about .075" on each side. So, I am wondering whether I did something wrong (yes, I know, besides buying the BBC style rockers) or is this common when using this type rocker? And, what is the next move- buy custom length push rods or new rockers (which I would like to avoid $gulp$). And if I get new rockers, will I still have to get custom push rods? Well, that's where I'm at presently. What do you guys make of this? Any advice is appreciated. Regards, M.R.
  12. Hi guys, I have a guide plate question. I have heard of people cutting their plates to get them to line up then re-welding. My question is: do the plate HAVE to be re-welded or can they be used as individual guides with the center link removed? M.Rad.
  13. J.H.C.! Even I never did anything THAT red-neck! Of course when it grenades, they'll say it's because it was a FORD...
  14. Yeah, I don't love the idea, but the prices for 4v ex. manifolds seems to have gone up lately. I checked my local Craig's List and Ebay and the only good set I saw was ~$300.00. Then again, I'm not after concourse originality. As long as it's serviceable and doesn't crack again I'm good. Just wanted to know if it was still an acceptable option these days. Thanks Blizz, M.R.
  15. Hi guys, thanks for the responses. I'm not sure if either (or both) of you are recommending staying with the 4V heads, or combining the 2V heads with the respective short blocks? My concern with using the 4V heads, both open and closed chamber, is the mis-match between their intended operating range, the available components and the range at which I will be operating the engine. George, I have read (and re-read) most, if not all, of your superbly informative articles both here and on your Pantera site, and have come away with the understanding that the 4V heads are designed to work toward the 6k/500hp end of the range. I will rarely see over ~5,000, except when trying to merge on to the highway from the feeder road. While the '71 4V would be the least expensive to put into service (cam change only), would it do what I need? I am limited to the 3:1 final drive if using a 3-speed automatic because the daily commute is about evenly split between half an hour at 70-75mph/ ~3,000rpm highway, and a half hour of 5-50mph/ ~2,000rpm city driving. Using one of George's charts I'm figuring compression to be about 8:1 with either 2V or 4V O.C. heads and 8cc dish (CJ block) or 8.7:1 with the flat tops. The CC heads with flat tops are roughly 9.5:1, again using George's chart. So, would the compression increase from the '71 CC heads compensate for the relatively lower port velocity compared to the 2V heads? The cast iron exhaust 2V or 4V probably (guessing here?) won't be too restrictive at these rpm.s when combined with 2.25" duals & H pipe I have, and the F351 intake also seems suited to the lower end of the rpm scale. That leaves cam selection- I got cam recommendations for a 2V 8:1/ iron manifolds/ F351/ 600cfm combination from Cam Research and Bullet. Cam research was 266*/268* (200/205@.050) .440"/.440". Bullet was similar 262*/266*(207/211@.050) .498"/.508", 112*LCA, 5* adv. These seem to be close to the stock '71 4V cam, and to George's CJ cam recommendation. Right now I'm leaning toward the 2V heads on the flat-tops short block, Cam research cam, and the other afore mentioned components (that way, I keep the correct numbers CJ block and heads together). I'm expecting about 300hp @ 4,500 / 375tq @ 2,500-4,000 which should coincide with my intended operating range. If you see any errors in my assumptions please let me know! I am, after all, asking for advice from your experience, not pushing my opinions. Regards to all, M.Rad.