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#61
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I think companies push the performance of their lifter face grinders, they push as many lifters thru until it barely meets the minimum requirements for surface finish. Lifter face grinding seems to just get worse and worse. The lifter is not finished to the outside far enough, sometimes it is too rough, sometimes the machining is not even straight. I have never lost a cam during a break in, a lot of people have though. For me, when a cam did fail, it was always in the first 3000 to 5000 miles, some at 10K looked like they could fail at anytime, but were still working. So when I hear a report that says the cam broke in, and all is well, I still am a bit skeptical. How much of the taper was lost during the brake in because the taper was poorly done on the lifter or cam, and or a component was soft? You simply do not know, and here lately since 2020 the machining and poor quality parts in general has been a dumpster fire. We don’t have time to tediously check everything either, so all I try too do is pick the best parts you can find or afford, and wait and see. Best you can do on a HFT is Nitriding, a good lifter finish, possibly DLC coating, and a profile that matches what your trying to accomplish with your engine combo. Last edited by Jay S; 01-26-2024 at 10:34 AM. |
The Following 3 Users Say Thank You to Jay S For This Useful Post: | ||
#62
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Whether people realize it or not there really isn't a huge demand for flat tappets these days anyway unless you race in some form of a restricted class.
Rollers have been in use since the 60's in race applications and oems adopted it across the board in the 80's and that trickled into the car hobbyist shortly after. Hell there is hardly even a crate engine offered today that doesn't have a roller whether it's from the oem's or your favorite crate engine builder. Literally millions on the roads for decades so it just makes sense. Failure is such a small percentage, worrying about it is silly. Take the tiny sample size from this site. Probably the largest Pontiac community on the internet yet it might make up what.....less than 1 percent of the car hobby in general? You have to put things in perspective, not to mention some failures posted on this site were completely self inflicted and not the fault of a roller at all. Everyone wants to make a mountain out of a mole hill. The biggest reason people don't want a roller is simply the cost. It's an investment, especially these days. After my son bought Johnson lifters for $1140 they raised their price to $1600. And I think that's where other people take a turn for the worst. Trying to find the cheapest deal out there doesn't usually pay dividends. You end up with reboxed crap that fails. You see it all the time with roller rockers on this site. No one wants to spend $800 for crower so they put cheap scorpions on then are pissed when they find pieces of rocker in the engine. Roller lifters are no different in the regard. |
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#63
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Why would a reseller want to sell $500 cam kits when they can push $1500 cam kits?Tom
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#64
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The slope on a cam lobe and the taper on a lifter have a lot of margin for error. You need slope and you need taper but it's not rocket science. Now what does come up and bites you hard is lousy metallurgy. It takes a really soft lifter to produce this in 15 minutes on the break-in stand. This was at the start of the crisis and cams were failing one after another. I found that Crower components were holding up and the setup that replaced the failed assembly is 16 years old with 12,000 miles so far and holding up good. That was years ago and while things have gotten better most of the lifters supplied are still softer than what they should be. A soft lifter will take out even a really good cam once the wear removes the taper.
As far as flat tappet vs roller sales, I can make more money through volume of sales. I sell six flat tappet assemblies for every roller and my overall profit will be greater. Unfortunately, if I unethically reduce my costs even further by producing an inferior product my per unit profit increases substantially. Of course the inevitable comes up and bites me when the cheaply made product fails.
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Mick Batson 1967 original owner Tyro Blue/black top 4-speed HO GTO with all the original parts stored safely away -- 1965 2+2 survivor AC auto -- 1965 Catalina Safari Wagon. |
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#65
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Any shop that cares about their customers should.
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The Following User Says Thank You to PAUL K For This Useful Post: | ||
#66
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I posted my lifter / cam failure two years ago. I had two lifters / lobe failures.
I did a complete teardown / clean / and rebuild with honing, new rings, bearings. Sent the heads out for refresh and new springs with pressure verified also. I went with the HT2148 roller lifters and spider/dog bone setup. Cam, lifters, , spider kit, pushrods, dist gear about $1000. My issue with this is if oil was the problem, how come ALL my lifters/lobes were not wiped out ? The other lobes had the taper and lifters still convex. |
#67
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The Following 3 Users Say Thank You to PAUL K For This Useful Post: | ||
#68
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Can I hear an Amen?
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#69
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Has anyone heard how expensive a FT lifter casting tree is as part of the manufacturing process? A lot. And even cooling during the process is critical. The lifter companies became only concerned with face hardness and made the issue worse thinking they were improving processes. Hochimin trail stuff.
Anyway the gradual even cooling of the lifter casting tree is what makes a quality lifter with the lifter face cooling first. Sets the acicular carbide? to the correct depth on the lifter face. Can't remember the depth 0.0200"?. Then you are ready to machine the radii. Or so I was told. Normal hardness is RC55-62? |
#70
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What cam are you using with the 2148s? |
#71
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My issue was I already have the Harland Sharp 1.65 roller rockers which are actually a ratio of 1.69.
Off the shelf roller cams would put overall lift too high for my valve length, causing retainer /seal clash. Here are my cam specs: Flow Tech Induction (Ed Curtis) designed; Competition Cams intake lobe # 3052, EX #3053, 230/240 @ 0.050”, I/E lift both at .321”, lift @ 1.69 = .542. Lobe separation = 114 deg, installed at 111 deg Event at 0.050” lift , Intake open 4.0 deg BTDC, close 46 ABDC, Exhaust 57 BBDC , close 3.0 ATDC Thankfully I still had a Mopar offset key kit P/N 4286500 in my parts bin to degree the cam. To use the HT2148 lifters, cam base circle must be at least 1.135” diameter, mine measured 1.189”. My cam base diameter combined with the .321” lift, put the lifter oil band is at the correct location. My oil pressure is spot on. I believe a cam lift can be up to .340” with these lifters and the dog bones. Higher lifts require careful check to ensure the engine lifter bore does not have a deep chamfer having the oil band exposed at max lift. Plus the dogbones need to be machined per 68hotbird’s thread. I bought Randy’s lifter which he swapped out the lifter plunger wire retainer with a C clip for $240. |
The Following User Says Thank You to Bill S For This Useful Post: | ||
#72
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I didn't read all of this, but the cost difference between HFT and HR has closed some, due to the drastic increase in the cost of HFT cam cores. Most of the HFT cams for Pontiacs at Summit Racing are now over $200, some over $300. A few of the Summit and Melling cams are still under $200, but probably not for long.
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'73 T/A (clone). Low budget stock headed 8.3:1 455, 222/242 116lsa .443/.435 cam. FAST Sportsman EFI, 315rwhp/385rwtq on 87 octane. 13.12 @103.2, 1.91 60'. '67 Firebird [sold], ; 11.27 @ 119.61, 7.167 @ 96.07, with UD 280/280 (108LSA/ 109 ICL)solid cam. [1.537, 7.233 @93.61, 11.46 @ 115.4 w/ old UD 288/296 108 hydraulic cam] Feb '05 HPP, home-ported "16" D-ports, dished pistons (pump gas only), 3.42 gears, 275/60 DR's, 750DP, T2, full exhaust |
#73
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Ultradyne has some lobes SR with .556 lift with 1.5s.
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Skip Fix 1978 Trans Am original owner 10.99 @ 124 pump gas 455 E heads, NO Bird ever! 1981 Black SE Trans Am stockish 6X 400ci, turbo 301 on a stand 1965 GTO 4 barrel 3 speed project 2004 GTO Pulse Red stock motor computer tune 13.43@103.4 1964 Impala SS 409/470ci 600 HP stroker project 1979 Camaro IAII Edelbrock head 500" 695 HP 10.33@132 3595lbs |
#74
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#75
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I just pulled some solid EDM lifters out was rubbing one with a fingernail and decided it was to rough so i worked it by hand with 1200 wet dry with oil .... NO i didn't lose any crown the way i did it. even pressure on entire face twisting lifter and 1200 on a hard face would take purposeful time and energy to bugger it up
you can still see how deep and course the original grind was ... still need to clean EDM hole
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If your not at the table you're on the menu A man who falls for everything stands for nothing. |
#76
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#77
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I think the retrofit is perfect for its intended purpose of modest lift lobes and thanks Jim Leheart for coming up with the idea! https://www.youtube.com/watch?v=fAKTh3uWBrE |
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