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#21
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Pix2
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'78 Macho T/A DKM#95, 460cid, SRP pistons, KRE 310 D ports, 3" pypes, Hooker 1 3/4" headers, hydraulic roller, 10" Continental, 3.42 gears 11.5 @117.5mph 3900lbs ([_|_] ##\|/##[_|_]) |
#22
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Ok just to nip it. I just looked at the pix i posted and they have a rust color. That is very misleading.
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'78 Macho T/A DKM#95, 460cid, SRP pistons, KRE 310 D ports, 3" pypes, Hooker 1 3/4" headers, hydraulic roller, 10" Continental, 3.42 gears 11.5 @117.5mph 3900lbs ([_|_] ##\|/##[_|_]) |
#23
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I think this might be a cam failure. Not a lifter failure. There is no roller flat spot. The roller never quit. Needle bearings seem ok
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'78 Macho T/A DKM#95, 460cid, SRP pistons, KRE 310 D ports, 3" pypes, Hooker 1 3/4" headers, hydraulic roller, 10" Continental, 3.42 gears 11.5 @117.5mph 3900lbs ([_|_] ##\|/##[_|_]) |
#24
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Maybe I should have named This Thread quote why did it fail because at this point I do not know
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'78 Macho T/A DKM#95, 460cid, SRP pistons, KRE 310 D ports, 3" pypes, Hooker 1 3/4" headers, hydraulic roller, 10" Continental, 3.42 gears 11.5 @117.5mph 3900lbs ([_|_] ##\|/##[_|_]) |
#25
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Like the roller and the cam lobe chewed each other up. Chicken or the egg
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'78 Macho T/A DKM#95, 460cid, SRP pistons, KRE 310 D ports, 3" pypes, Hooker 1 3/4" headers, hydraulic roller, 10" Continental, 3.42 gears 11.5 @117.5mph 3900lbs ([_|_] ##\|/##[_|_]) |
The Following User Says Thank You to jonmachota78 For This Useful Post: | ||
#26
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Once the lobe got worn to the point of having enough of a groove the ware rate will sore!
The groove will grab at the sides of the lifter roller and then slow down its ration .
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Wernher Von Braun warned before his retirement from NASA back in 1972, that the next world war would be against the ETs! And he was not talking about 1/8 or 1/4 mile ETs! 1) 1940s 100% silver 4 cup tea server set. Two dry rotted 14 x 10 Micky Thompson slicks. 1) un-mailed in gift coupon from a 1972 box of corn flakes. Two pairs of brown leather flip flops, never seen more then 2 mph. Education is what your left with once you forget things! |
#27
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Hmmmmmm
GT |
The Following User Says Thank You to blueghoast For This Useful Post: | ||
#28
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Is it a cast iron core or billet?
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#29
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Is that push rod straight?
Was there not enough retainer to guide clearance? Just grabbing at straws here since the only other reason to me would be the core was hardened uneven.
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Wernher Von Braun warned before his retirement from NASA back in 1972, that the next world war would be against the ETs! And he was not talking about 1/8 or 1/4 mile ETs! 1) 1940s 100% silver 4 cup tea server set. Two dry rotted 14 x 10 Micky Thompson slicks. 1) un-mailed in gift coupon from a 1972 box of corn flakes. Two pairs of brown leather flip flops, never seen more then 2 mph. Education is what your left with once you forget things! |
#30
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Quote:
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'71 GTO, 406 CID, 60916, 1.65 HS, '69 #46 Heads 230CFM, 800CFM Q-jet, TH400, 12 Bolt 3.55 '72 Lemans, Lucerne Blue, WU2, T41, L78, M22, G80 |
#31
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Well...that sucks. Sorry to learn of this.
Do you always use the same brand and grade of oil? |
#32
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Quote:
In that first photo I thought it was looking kind of tough also. Just from that first photo, it was not a better 8620 cam core, it is obviously not a cast cam core either. Looks like a 5150 for 8660 cam core. My guess is a 5150, but I can’t tell those last two apart from the photo. The hard surfacing is not as thick on those cores…IRC, it would have to have pretty minor damage to be reground, it is a possibility though. It could be the cam surface gave up over time, or it float the valves at some point and started to dig in to the ramp, it does have a good amount of lift. It could also be some needles in the roller bearing are gulled and dragging hard under a load. I suppose it could have even got some contaminates in the oil and cause that too, kind of unlikely though. Only way to eliminate the lifter as the cause is to press the axle out and look over the needles. That’s a bummer, at least it sounds like you had a lot of fun with it. |
#33
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Quote:
He replaced the lifters under warranty with the "new" S comp lifters that came out in early to mid 2014, replaced them in late 2014 according to my notes. So these lifters werent the shavers, look like my originals from the pics, either johnson or morel. Is it possible the lifter wheel wasnt hardened right to cause that damage? Pretty sure the OF cams were billet, thats why they require a poly or brass dist gear. Bearings could be bad too but still roll ok under no load? |
#34
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On the all the copies of SD Performance cam cards I have on hand they have either part # 51-000-9 or # 51-000-11
The last number, both the 9 or 11 indicate 'Steel Billet Roller'. .
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'70 TA / 505 cid / same engine but revised ( previous best 10.63 at 127.05 ) Old information here: http://www.hotrod.com/articles/0712p...tiac-trans-am/ Sponsor of the world's fastest Pontiac powered Ford Fairmont (engine) 5.14 at 140 mph (1/8 mile) , true 10.5 tire, stock type suspension https://www.youtube.com/watch?v=qDoJnIP3HgE |
#35
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'78 Macho T/A DKM#95, 460cid, SRP pistons, KRE 310 D ports, 3" pypes, Hooker 1 3/4" headers, hydraulic roller, 10" Continental, 3.42 gears 11.5 @117.5mph 3900lbs ([_|_] ##\|/##[_|_]) |
#36
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Fortunately you caught this before there was catastrophic damage. The damage you have is manageable. Why did this happen specifically on one lobe? That can be hashed out in these posts forever without a clear answer. As one of the few on the forum who still have little issue with flat tappet cams, this is just one more example that a roller is not a 100% cure for wiped cam lobes. It did enjoy a pretty good life span for a performance engine. In the time period you purchased and installed these lifters, Comp and many others were sourcing lifter wheels and needle bearings from various Chinese vendors. There were a considerable number of failures as we know and everyone was pointing fingers and blaming suppliers. So much so that in this time frame Crower began making all the wheels in house and axles. Also only US sourced needles. That is not the case today as they feel they have found some quality imports for some components. All we can do as end users is try to buy the very best components we can afford and cross our fingers. Hope you can get it all back together and save that camshaft.
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#37
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Mike,Comp has not made their own hyd roller lifters for many years Johnson supplied them,Isky and Clay Smith for many years.They went to Ron Shaver Industries here in So Cal to make the S lifters and subbed Morels if out.Many cam company's buy from Morel.Comps new lifters look like Shaver bodies with in house made replaceable cartridges.Actually made by a Edelbrock company.I dont think any of the major cam companys are knowingly buying China made hyd roller lifters.Tom
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#38
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Quote:
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The Following 2 Users Say Thank You to mgarblik For This Useful Post: | ||
#39
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I'm always interested in how and why stuff breaks.
This must be very frustrating, and I don't minimize the pain of this discovery. Just thinking out loud with my fingers.... It seems the roller still rolled, so maybe this was just a case of contact fatigue? If so, then it may be inevitable, depending on the design? If the contact stress is high enough, all the hardening and materials quality in the world might not be enough to prevent eventual failure?? And I will always jump on the bandwagon suggested by mgarblik. It's not about being made in China, it's about a failure to manage the design and quality, no matter where it's manufactured. Unfortunately, when you source parts from foreign suppliers, it's way to convenient to blame your own failure on your supply chain. IMO, you buy the parts, it's on you to make sure you get what you need. |
#40
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Theres witness marks but you cant catch a nail on it
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'78 Macho T/A DKM#95, 460cid, SRP pistons, KRE 310 D ports, 3" pypes, Hooker 1 3/4" headers, hydraulic roller, 10" Continental, 3.42 gears 11.5 @117.5mph 3900lbs ([_|_] ##\|/##[_|_]) |
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