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#341
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I have not run this setup myself. I did help a buddy set his up.
What we ended up doing is simply throw the lifters on my surface grinder and take down the flat on both sides. We looked at this a couple of different ways and I do not feel this is a best fix. My preference is to use stock components wherever possible so that roadside (shop) repairs are possible. That will not be the case on the road. After reviewing where the issues are at, I would prefer to build new dog bones with relief for the lifter body. These would be a little thicker, but allow for any stock or equivalent replacement lifter. While not a factory part, I feel that it is probably not a real wear part. I can have these made easily enough so we would have some backups. I did not check the hardness of nor tried to cut the factory dog bones. But I am sure a Pontiac specific replacement part would be easy to get done. Dave
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'68 Bird Vert, 455 , 6x-8, 1.5 HS, HEI, PPR TC-02-HF, TH400, 2500 Hughes, 2.56 8.2 (getting swapped for second gen with shorter gears) Fishing guide in the Washington state for Salmon, Steelhead and Sturgeon. Fish-On! |
#342
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OP hasn't updated since January of 2021...over two years ago. I wonder how this worked out for him?
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Jeff |
#343
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As far as lifters and oiling bands and oiling holes, Crawdaddy Customs did a video looking at a variety of GM .842 replacement lifters -> Here it is: https://www.youtube.com/@CrawdaddyCustoms/videos
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#344
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Franked, you mention you are looking for a solution for issues with this adaptation of a stock style roller lifter for how your engine is configured, what are the exact problems you are trying to solve? Is it because you have more lift than the dogbones and spider can handle, or something else? I am curious since I have been looking at doing this conversion (with a look to avoiding the failures of the tie bars on aftermarket roller lifters). My application is a street application with E heads, and I am not pushing the lift numbers much past .520. I am still looking for the right cam and lifter combination. Jim Lehart came up with the original developments and use of this option: LSX hunter covered it briefly in a video on his channel https://www.youtube.com/watch?v=fAKTh3uWBrE
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#345
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So, the more I am thinking about this, the more i think I may try yo find some flat-bar steel the right thickness, and width(to be slightly narrower than the dog bones) and weld a strip & grind it down to make the bones, say .050 thicker on the bottom(not at the open end wrench part) so they are high enough to clear the round part of the lifter coming up.
I also think that my roller cam ramps may be too steep, they were hitting on a stock '05 GTO LS2 lifter, I wasn't sure about this, until I read through this whole post and saw that part a couple pages back, thinking I was not really seeing that on my engine. Aparrently I WAS seeing that. it's not a sealed power lifter, if the sealed power lifter hits like that, I may try clearancing the lifters with a flapper wheel on an angle grinder, just bevel the edge slightly so there is at least .010 when it rides up the steepest part of the cam. My cam is a Butler Spec'd Comp cams grind. BP8022SP, INT 281, EX 287, LIFT INT.510, EX .520 i was wondering if anyone has tried making the bones thicker on the bottom, and if anyone has clearanced the lifters by the roller part. I think that would be much stronger than the ones with legs only supporting the axles, I have heard of those failing somewhere in the past where the legs spread out. is the roller significantly larger on the exposed roller lifters? a bigger wheel would be easier to roll up the steep ramps, I suppose. Frank |
#346
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So in my other recent post I noted that Crawdaddy Customs looked at oiling, but if I remember correctly, he also examined some other things with the lifters in his video, not just the oiling - perhaps with the spiders and "bones" too. Something to look at. He did 2 videos - this is the first one: https://www.youtube.com/watch?v=50I58n4vD8U
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#347
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I'm building a 400 (+.060) block, with a 4.250 stroker crank, making a 468.
I bought a partially assembled short block, cam and crank were installed. pistons, rods, rings were still in boxes. block was already bored, but not decked, and I am getting new cam bearings installed, my machine shop guy wants to re-balance the rotating assembly with the balancer and flywheel. and he is going to fit the rings (Mahle, forged flat tops, 9.7 to 10.3:1 depending on how much we deck the block, and the thickness of the head gaskets. I ordered Edelbrock D port heads, CnC'd to 310 CFM from Kauffman, i expect those late may or early june. the cam that came with this stroker kit is a Butler Grind Comp cams BP8022SP .510/.520 lift 281/287 duration. 112* lobe separation. When i put a couple used LS2 lifters in it (from an 05 GTO) and rotated the cam, the dogbones lifted about .030, and it looked like the full bottom of the lifter hit the lobe a little lifting the wheel from the lobe. I have some 2148s showing up to try, but I wanted something factory reliable and lightweight instead of the heavy link-bar type lifters. I do NOT plan on taking this engine past 55-5600, but I want a smooth operating valve train. Frank |
The Following User Says Thank You to Franked For This Useful Post: | ||
#348
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Just an FYI for those reading, the weight of a link bar setup shouldn't even be a player in the grand scheme of things so long as the rest of the valvetrain is setup properly (IE: correct spring pressures) And with these low revving Pontiacs that people are typically building in here, it's really a non issue.
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The Following User Says Thank You to Formulajones For This Useful Post: | ||
#349
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I know, grease the wheels but there seems to be no magic retrofit bullet. And then the added cost… |
#350
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Most guys here don't even spin their Pontiacs above 5500, and many others don't make power much above that. It's the street section. With a proper spring valve train control is not an issue with these things. If you want to save weight on the valvetrain then look at retainers and valves and don't worry about link bars. |
#351
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I was all on board to go the LS lifter route, but just couldn't pull the trigger. I feel bad for Randy going to all that work to make the plate system only to give up on the idea.
To me it seemed like there was too much block casting inconsistency for the plate system to work. Too much cam inconsistency - But Randy had a few flavors of lifters to accommodate the different lifts/base circle. Didn't like how the dog bones would lift up and needed modified with use with the spider. Didn't like that there just were not very many people using it. I think the lifter weight is more significant. Heavy lifters need more spring pressure. More spring pressure = more wear on the rollers and thus more prone to fail. Not sure where lifter float come into play but I would imagine that too. In the end I went the johnson short travel rollers too. Glad I got them at the 700 price and not the 1100 price. |
The Following User Says Thank You to rohrt For This Useful Post: | ||
#352
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Franked, my build plan is fairly similar (in general terms) to yours, I just plan on using Kauffman D ports instead of the Edelbrock D ports. If you take a look at Jim Lehart's original methodology, you will probably see possible solutions to the dogbone clearance problem. When you combine that with Crawdaddy custom's look at lifters, and which ones seem to fit best, I think you can formulate a workable solution, without having to fabricate 16 dogbones when all the originals may require is some mild grinding as Jim Lehart did in his builds. Just a thought, YMMV.
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#353
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Formulajones, it is not the weight that concerns me. It is the notable number (still I have not done a survey, so it's anecdotal experience information to be sure) of Pontiac, Chebby (both BB and SB), and F*rd folks who have been having link bar failures in street driven or street/strip driven cars. The spider and dogbones are (in factory and aftermarket use in F*rds) seemingly very reliable, and the movement of the spider is well within it's spring range, and as long as the lifter roller does not fail, the dogbone is not under significant mechanical stress. For everyone who has investigated or is interested in doing this option, you need to go back to the source (Jim Lehart) and his prototyping and how he completed engines, and how they are running now to determine the proper way to do this and whether you want this as an option over a link bar system. Comp cams isn't going to do it because there just isn't enough $ in it for them compared to the bajillion f*rd small blocks out there, and there is a proven system for the chebbies too.
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#354
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When you think about how many link bar roller setups are in service around the country, or world for that matter, without issue, then it's starts to come into perspective a bit. |
#355
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Sorry to hear that you put all that work into trying to figure out Jim's LS lifter conversion for our Poncho's. It was still really useful info for those contemplating the project! I appreciate your experiments and the videos you do documenting them. Quite a bit on your firebird is similar to my '69 GP.
I think after looking at Jim's original information that I am still heading down the path to using the F*rd spider and dogbones to use an LS style lifter in my 428. I'm probably going to talk to both Kauffman, Butler, and DCI (Don is building my friends aluminum RAV headed engine now https://www.facebook.com/DCIMotorspo...qiMWmPriBrhqwl) before I start buying parts though. Quote:
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#356
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A typical hydraulic roller in our Pontiacs, considering the valvetrain weight, really shouldn't need more than 150-160 lbs. on the seat and maybe 420-450 lbs. open as an example. Pontiacs do have heavier valvetrain with their 2.11 intake valve and 1.77 exhaust valve sizes being bigger than a SBC for example. Speaking of which a SBC might only use 130lbs as an example. But those spring pressures can easily control a hydraulic roller well beyond what most would spin their Pontiac engine to and no worry of excessive wear. In fact I set dad's Pontiac engine up with a hydraulic roller and he's running a 2.20" intake valve, it's 160 on the seats and 450 open. It's gone several thousand miles, and I think 3 years now since the change, can't even tell you how many times he's put it on the 6200 chip for one reason or another. My BBC has a 2.25 intake valve, known for valve train control problems, and runs those same spring pressures. That engine has been together almost 25 years like that with a hydraulic roller, never had a valve cover off since and has no problem spinning 6500 rpm. Going racing this Saturday with it as well as dad's car I'd bet after 25 years those spring pressures are significantly less by now. All this stuff is typical link bar setup. I think where people get into trouble, and I've had this issue myself, is when getting into solid rollers and the spring pressures they require. Had one of those in dad's engine too, that had a very typical 240 lbs. on the seat. Tony Bischoff set that deal up and used what is an acceptable street type spring pressure for a solid roller, tight lash deal, pin oiled Crowers etc..... They lasted about 7000 miles before it ate 2 lifters. Roller wheel failure. Lobe design plays a roll in this as well but when you are using race type parts on the street, along with lash, and spring pressures up in this range, you have to expect it's not going to last forever. Crower had no other explanation, I don't hold them accountable either. It's just the nature of the beast. Moderate hydraulic rollers however with proper spring pressure, not even on my page of concerns. |
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#357
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I'm not sure when I will get them, and my Machinist guy lost his helper in the shop, so that may be a while too for me to get the short block back, I have no issues rounding the edge of the bones so they sit flat, I could do that part in half an hour for all 8 bones. welding .050 strips on 8 bones and then making sure they are still flat will take a little longer, I think I could figure all that out and get it done in a 3-6 hours. IF, that works (notice, BIG IF) it may be ALL good, and then the only issue is to separate the spider, and re-build/bend it so it sits right on all the bones, and I am done. I would still need to get the heads on and use an adjustable push-rod checker to get the right length pushrods ordered. For me, I like doing stuff that uses easily accessible parts, but not many people do, something different that I built myself. I have never liked the link bars, seems like MORE parts to wear, that don't have a bearing, also I feel they are a little noisy, and want stuff that goes a hundred thousand miles in regular production engines with little issue. I would just put a 500hp LS in this car, and reduce the weight by 250 pounds in the front of the car, and I may do that eventually, I do like the idea of REAL PONTIAC power, though, with a couple modern improvements. Roller cams are all that is in modern cars, and the cylinder head improvements over the last 50 years will also make this much better than original. Frank |
The Following User Says Thank You to Franked For This Useful Post: | ||
#358
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Well, I got my heads a few weeks ago, they are KAUFFMAN D-ports, not Edelbrock D-ports, not sure why I thought that, must have been confused during the conversation, when ordering. I have them at my machine shop, so my machinist guy can bash on them, he is super picky, and builds a lot of high RPM racing stuff that wins a LOT, so I can listen to his bitching. He keeps telling me I don't want over 9.25 to 1, the stroker kit/head combo is designed for 10-1 or 10.3 to 1, Kauffman didn't have larger than 85cc chambered heads, so we may be putting thick gaskets, and or leaving the deck height as high as we can.
My Machinist guy says with CA's piss gas (max 91 octane) I really don't want over 9.25-1, or I will have to mix in race gas, and/or have no timing advance. Any thoughts on this? the gas here does suck for high compression. Frank |
#359
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Franked, I could be wrong, but IMO, and strongly suggested by current production engines and typical, recent hot rod builds of aluminum head engines, your machinist is in left field, crap gas or not. An engine built with aluminum head is significantly more tolerant of poor octane fuel than an engine with iron heads, even without regard to the dynamic compression influence via camshaft timing. The much higher heat loss rate associated with the aluminum heads significantly reduces the chances for detonation. Most non-turbo V8 builds now with aluminum heads are comfortably running compression ratios at (or above) 10.5:1 on 89-91 octane fuel - as long as the fuel/air mixture is not really messed up. I would seek out the direct advice from either the folks at Butler, Kauffman or Don at DCI. motorsports. For a small example, my wife's mini-van has 11.3:1 compression and is comfortable with 89 octane fuel, and makes over 280 hp (stock) with only 3.6 liters (non mini-van versions are rated at 310 HP). Granted it was designed with variable valve timing, 4 valves per cylinder, electronically controlled fuel injection and ignition, and a modern head design. The 2 liter Turbo Direct Injected 4 cylinder in my daughters car makes 200 (stock) hp with 10.5:1 compression (but requires 91 octane fuel). The aluminum Kauffman D port heads are said to have an excellent chamber configuration, that is highly detonation resistant, and that combined with being aluminum makes running 105:1 compression roughly the iron-head equivalent of 8.5:1 (I'm sure that the folks at Kauffman can give you a better number than that).
Last edited by 1969GPSJ; 08-08-2023 at 12:32 AM. |
#360
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Another interesting thing is, this engine now runs best with 31 deg ignition timing, where with the 87cc heads, I needed 36 deg. |
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