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#41
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One thing I ask to determine if a HR profile is going to be quiet/fairly gentle, ask the cam grinder what that particular HR profile would require for lash if you were to run it as a HR/SR hybrid. Like Tom’s magnum example was .008” lash, a comp XFI HR profile is .005” lash or less, the XR is inbetween. Running those cams as a hybrid they start getting pretty noisy at lash’s larger than what is recommend. A lot of people complain their HR cam starts to get very noisy when the engine is really heat soaked, in those cases the extra noise is likely coming from cam profile and the lifters. The profiles that are able to run more lash as a hybrid are generally quieter running cams, both as hybrids or HR lifters. Especially true on a heat soaked engine.
I have had tight lash street SR profiles picked out and was steered to a HR/SR lifter hybrid set up by cam grinders. I know a lot of people say the HR’s are not designed for a SR, but some of the HR seem to work well either way. The SR I had picked out was a tight lash street roller in the mid .6” + lift range, had a lash of .015”, spring requirements were 180-190 seat and 450 nose. The cam mfg said overall longevity would be better with a HR profile with SR’s. The HR’s design ramp with a SR lifters was .010” lash and 160-170 seat 400 over the nose. I wanted to be able to move the lash around on that cam to make sure we had the cam “close” the what the engine was wanting. Zero lash cold on the narrow end, they looked up the max jerk for that particular profile on the computer and said the max I could go was .014” lash on the wide end. It had more lash range than the SR profile I had picked out. Overall in that case the HR hybrid set up was a better fit. Not saying it is for everyone, seems to have its place though. Last edited by Jay S; 12-01-2020 at 10:29 AM. Reason: Edit |
#42
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I'm curious about the comment that setting cold lash at zero will result is a small amount of gap when warmed-up. I thought the opposite happened? If pushrod and valve lengthen with heat, wouldn't it reduce lash?
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Hoping to finish a project while I'm still able to push the clutch in.... 1963 Tempest Convertible (195-1bbl, 3-speed transaxle. 428 RAIV, 5-speed, IRS planned) Pictures |
#43
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Pushrods don't really grow, but the heads do, increasing the lash when hot.
Typically iron block and heads see the least change, maybe .002" or so. If you run an aluminum head you might see as much as .006" or more. Aluminum block and heads grow even more. |
#44
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The exhaust valve grows more than the intake, cast iron heads with zero lash on some engines you have to give them more lash or you will get an exhaust backfire when it warms up. I don’t think it would ever bother with aluminum head.
On our 69 Charger we were fooling around with the lash years and years ago, when it got warm it started to have a pop out the exhaust and caught the gas tank on fire! 3” exhaust that dumped in front of the back axle. Thank God for fire extinguishers! After that we make the effort to put on tail pipes. Lol Back earlier yet we had a Ford 6 cyl we built up for a pickup with a hft cam. The hydrualic lifters for what ever reason, would not do ANY compensating. As soon as it had preload it had a miss, didn’t matter which lifter either, happen on all of them. It was kind of bizarre, I believe it had something to do with the oiling system we were running and not enough lifter leakage. It acted like what you would expect to happen when the lifters pump up at high rpms. To get it on the road we zero lashed it cold and ran it. It ran 200,000 + miles like that and never gave an issue. Last edited by Jay S; 12-02-2020 at 01:30 PM. Reason: Typo |
#45
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So, I have an engine I built quite some time ago. I have yet to fire it. It has a new set of Comp 857-16 lifters in it from 2009. The cam is Comp custom grind w/ 236/248@.050" and .391" intake lobe. It will be street driven. Should I expect to have problems?
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Hoping to finish a project while I'm still able to push the clutch in.... 1963 Tempest Convertible (195-1bbl, 3-speed transaxle. 428 RAIV, 5-speed, IRS planned) Pictures |
#46
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I think those are Johnson lifters if from 2009.Was the engine pre lubed when it was built?Only one way to find out is to get it on a runstand or dyno before putting it in the car.Tom
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#47
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Yes, I assembled everything with assembly lube and coated the cam lobes with some spray lithium grease to protect them since I knew it would be sitting a while. I'm thinking seriously about pulling the engine and checking a few things while it's easy. That story about the Clevite bearing issue #5 hitting crank radius before the #4 thrust face touched has me spooked. It's sitting in the chassis without a body so it's pretty easy to pull.
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Hoping to finish a project while I'm still able to push the clutch in.... 1963 Tempest Convertible (195-1bbl, 3-speed transaxle. 428 RAIV, 5-speed, IRS planned) Pictures Last edited by tekuhn; 12-02-2020 at 02:45 PM. |
#48
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When I first put the "hybrid" set-up in service I started at .008" lash. It was dead quiet cold but started to make just a very slight ticking fully warmed up and heat soaked. I re-checked the lash and the intake lash was up to .010" and the exhaust up to .012". Those measurements were pretty consistent across all 8 cylinders.
I dropped the lash to .006" and ran it that way for a few hundred miles, nice and quiet and no issues. The next time in I reduced the clearance to .005" and have been running it that way since 2009. In all that time zero issues aside from grinding up the PRW stainless steel roller rocker arms that were supplied with the heads, cam and lifters. They were replaced with Crower Enduro's and not a hint of noise or any other problems since. Personally I really like the "hybrid" set-up. The pro's are the quietest valve train you will ever have on one of these engines. They are also NOT RPM limited. With the Crower HIPPO lifters the engine will rev right past 6000rpms so fast on a hard run you can barely move the shifter fast enough to keep it from going past 6500rpms! My engine shows no signs anyplace of loosing power or power falling off well past 6000rpm's even though it probably makes peak HP around 5800rpms. Negatives are valve adjustments. A Pontiac engine in a Nova body car with power brakes and AC was never meant to have a solid lifter cam in it. It's a huge PITA to run the valves. I can barely get the drivers side valve cover off and can't get to the last two valves well enough. The wiper motor has to come out, and to really do a good job and make it easy the master cylinder and brake booster as well......
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If you can read this, thank a teacher. If you can read this in English, thank a Veteran! https://cliffshighperformance.com/ 73 Ventura, SOLD 455, 3740lbs, 11.30's at 120mph, 1977 Pontiac Q-jet, HO intake, HEI, 10" converter, 3.42 gears, DOT's, 7.20's at 96mph and still WAY under the roll bar rule. Best ET to date 7.18 at 97MPH (1/8th mile), |
#49
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I meant priming the oil system!Tom
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#50
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Yes, I removed the distributor and spun the oil pump until I had oil pressure and then also spun the engine using the starter with the plugs removed while maintaining oil pressure with the drill. I had the rockers backed-off so all the valves were closed and not presenting a load. The engine seemed unusually tight for several seconds and then suddenly freed up and spun much easier. A few days after this, I noticed some oil on the floor from the rear main. I suspect the seal had bonded to the crank and was spinning with it until it freed-up. That's one of the reasons I think I need to pull the engine and check it out before I start it for the first time. I used a 2-piece Viton rear seal and think I should switch to the BOP one-piece.
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Hoping to finish a project while I'm still able to push the clutch in.... 1963 Tempest Convertible (195-1bbl, 3-speed transaxle. 428 RAIV, 5-speed, IRS planned) Pictures |
#51
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"I used a 2-piece Viton rear seal and think I should switch to the BOP one-piece."
That is still a good seal. I have used them on 2 separate motors and neither one leaked a drop. Sent from my SM-G965U using Tapatalk
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68 Firebird-- Street/Strip - 400/461 Eagle Forged Bottom End & Ross Flat top pistons. KRE 325 CFM D port, Ultradyne 263/271 @.050, .4267 lift. Crower Solid roller lifters and 1.65 stainless rockers. Quickfuel 1000 on Torker2 intake and 2" open spacer. Hedman 1.75" headers. TH400 w/brake. Ford 9" w/3.80 gears & 28x9 Hoosier pro bracket drag radial. Best ET: 1.35 60ft, 6.29 @ 107.20 mph, 9.99 @132.33 mph. 3,300 race weight |
#52
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Quote:
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#53
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Hyd Roller Lifter Oiling
One area you don't hear about with the drop in Hyd Roller Lifters is the lifter body going below the oil feed hole in the lifter bore. The measurement is 2.000 from the base circle of the roller cam to the top of the oil feed hole in the lifter bore. This measurement is based on a 1.080 base circle cam.
Using our big .400 lobe lift cams, the Gaterman 1012 lifters still have a little room to spare as pictured in the first two pictures. The Sealed Power HT2148 lifters will expose the oil hole and spurt oil when the cam is on the base circle. Our .377 lobe lift cams have a 1.135 base circle and work fine with either lifter. Test your setup prior to firing it up by installing the cam and just placing the lifters in the bores. Keep the valley pan off and use your oil priming tool to prelube the engine and you'll see if it's losing oil. Some oil seepage around the lifter body is to be expected but if it looks like the Clampet's striking oil on the Beverly Hillbillies, you're asking for a rod or main bearing failure. The key is to use a Hyd Roller cam with a 1.135 base circle or larger on a HT2148 lifter. Let me be clear, it will run regardless but at continued high RPM it will pump the oil to the top and bearings are going to suffer. For anyone who has built an engine with these lifters and a large hyd roller cam, IF you don't know your cams base circle dimension, call your cam manufacturer and find out. The hobby can't afford any more Pontiac blocks being destroyed. Pics on our page at facebook.com/pontiacspeedshop
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Randy Repp 1964 GTO "GoatZilla" 1964 GTO "Injunuity" A/FX Nostalgia Super Stock 220" Rear Engine Pontiac Powered Dragster https://www.facebook.com/PontiacSpeedShop/ https://www.facebook.com/GoatZillaRacing/ https://www.facebook.com/groups/RebuildExcitement/ https://www.facebook.com/Call1844RacersRV/ https://www.facebook.com/groups/INJUNWARS/ |
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