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Old 09-11-15, 06:36AM   #136
Zedo
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Jim, Eagle and Scat cranks are made in China. I don't care how good or bad they are, they are a BAD choice considering what's going on lately. there just has to be some other way, IMHO, to build a Pontiac engine, rather than putting Chinese parts in it.

I have the Olds thrust bearing and some shims a friend made for me, and a cut down 455 3" main crank, to build one of these 3" main 455 engines. The bearings are no big deal. Just buy an Olds main bearing kit, and pull the thrust bearing out and use it. but thanks for documenting the part numbers here on the database of the individual bearing. that makes it easier.

for street use under 500 HP, a full groove bearing is just fine, and oils the rods a tad better. I agree for high HP apps it's not a good idea, less oil film/load bearing surface.

yet the superstockers running 455's used to run full groove bearings, and open up the groove even wider, to get the bottom end to live. the whole setup is in Pete Mc.'s first manual for SD455. so there is conflicting tech info on that. those engines get torn down so often, it doesn't really matter.'

back in the old days, a lot of engines ran grooved cranks, or full groove bearings. I built one full groove main bearing 428 bottom end, 4 bolt main, for a guy. it ran in the low 12's in a 4000 lb. car w/driver with 9.5 CR on radials, pump gas. The guy put his own E-head top end on it, it was running those cheap stainless valves in it. eventually it dropped a valve, and holed a piston and bore. when he pulled it apart to have it sleeved and the head fixed, I stopped by and checked the bottom end.

one year of bracket racing every weekend, the bottom end bearings looked like the day I put them in, like new. and it had full groove mains top and bottom. the rod bearings were mint.

a full groove bearing does oil the rod bearings a tad better, but there are counter risks are you said. not for a 750 HP motor. but ok for a 450-500 HP motor on pump gas.

then there's the issue that a non-crossdrilled crank, should have a full groove bearing. I built a 400 with a non-crossdrilled crank, casting 12 heads, with stock half grooved bearings, and ran it for 2 years hard on the street, street raced every chance I got, and bracket raced it on weekends, driving it back/forth to track. eventually it broke top rings lands on one cast piston from detonation. so I pulled it down, replaced the slug, and put new rings in.

the bottom end bearings in that, were perfect too. go figure. there seems to be no hard fast rules there, I think a lot depends on driving style, proper clearances, and the oil used. I always used Amsoil and it is very forgiving of abuse. it keeps engine temp down and is superior in lube quality. when I ran regular oil, the engines could not take as much abuse.
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Old 09-11-15, 09:09PM   #137
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I see nothing but negativity on this board for welding of the thrust on a nodular crank and yet my grinder assures me there will be no problem with it and has a top-notch reputation to uphold. I will ask him to guarantee the thrust conversion by replacing the crank if the thrust fails after he welds it. To be evaluated by Leo who he knows. It seems hard to believe no one has had success with the modification. I would be nitriding and cryo'ing the completed weld which most probably dont do as well. Ther is still a question which way he will go ... he should have it by now. In reexamining my HO book I see they recommend hard chroming the thrust surface to correct spec for small journal ... but see they also recommend starting with a forged crank for the 3.25 to 3.00 conversion. Not sure that can be done to an "N" crank ... will ask Adney. That seems most appealing to me ... standard bearing set and chromed thrust without welding. I personally hand fitted a P-Dude kit on my block downstairs and see the perimeter and a significant portion of the thrust surface has no support from the shims ... evidently this has caused zero failures according to those here ... sure doesnt give me warm fuzzies tho.

Cross-drilling .... can anyone explain the newfound negativity on this procedure? HO says all big journal main cranks were crossdrilled and used 1/2 grooved mains whereas small journal ran full-grooved without crossdrill. They recommend crossdrill and teardrop main journal oil-hole .. double tear-drop rod journal to enhance oil delivery and distribution to rod on either size crank. I believe there is a much more prevalent failure rate at the rod journal in big journal cranks ... possibly due to the higher piston speed and heavier piston compounding the force on the rod bearing ... not to mention the factory engines would probably rev like a 400 leading people to drive them past their safe limits.

How is Amsoil oil acquired, is that the stuff they have a PH like kit with to test it and see when it needs to be changed like extended life anti-freeze on trucks?
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Old 09-12-15, 12:14AM   #138
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Keith two things, HO book is 30 years old. Old old Technology . The other I had my 3.25 main cast crank, cut down to 3.00 mains and welded. I had crankshaft specialist do it They hard chrome it. I had him do it with confidence because they are one of the best. They used to do all of Nunzi and Maxey's cranks.

My thing is having someone do it that has a track record, with a history of the cranks living. In a 650 hp motor. I think that's what's everyone trying to say.

P-Dude uses the shim and I believe olds bearing and has a history of success, here's the thing, by the time you have someone cut and weld it nitrate it or hard chrome it, it's just cheaper to go buy a steel crank.

My crank lived for 200 passes at 650 hp them broke two. Back then we had no other choices. If you feel confident that this guy can do it and not have any problems hey knock yourself out.

I just know guys who have with very poor success. If it was me I would go spend $650 and go buy a nice steel Crank, But that's just me, my theory is your taking a crank that God only knows how many miles are on it. How many times the motor it was in has been overheated, or detonated.
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Old 09-14-15, 10:01AM   #139
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Gach, thanks for sharing that, so when you say you had yours welded that means just the thrust or was the weld a repair also? Did you have just the thrust chromed or journals too? I was thinking nitride crank then chrome only thrust surfaces to supplement weld area, this 444 will be a street motor and will never see 200 passes at the dragstrip or ever crack 500hp most likely according to you with my Nunzi cam which will be going in it ... should make a fun street cruiser I can take to the track when I want to tho, my previous post was me just feeling alittle disheartened by all the negativity here, Im choosing to modify factory cranks, which can be done and I was curious how far they will go so Im going to experiment. I may find out with the next motor, a full stroked 400 crank to 2.100 rod journal (my Poncho 427) ... there will be no welding on it. BME and Ross pair. I dont want to drive the 444 being worried about the crank grenading all the time ... I'm not going to buy a new foreign crank forged or cast to quell that fear however ... from what Ive read Poncho factory cranks are stout, and if still straight and uncracked after 50 years Im willing to give em a go before a China doll. Long as I got a good grinder Im hoping Adney's crew will be.
I had seen a post of yours on another board around 05 talking about another mod to do regarding rear seal I think with this conversion but now I have lost it. My crank is at the shop in Detroit now, Adney said they would mag it and tell me what his suggestions are for this conversion. He has already told me he felt as you do. He does do the work Im asking for and has an excellent reputation however. The prices are not far apart for my dollied up N vs a forged RPM. I think Im still lower as I would have to cut the RPM too and would do my nitride and cryo deal as well.
As far as HO being antiquated you just told me I could use their diagrams for porting my d-ports for 75hp or so, I know they are old school but I am too as are all my engines and the Pontiac cars they are going into. That Pete M video is old hat as well but I would be happy with 11's as you got using it it.
Frankly Im no spring chicken either I have railed here about factory cranks and by golly Im going to use them till I break one .. have never even thrown a factory rod yet so that might be awhile. I have the opportunity to try to create some factory strokers with my stuff and will give it a try. Just wanted to gather as much info as I can to do as wisely as possible. Crankshaft Specialists are the guys in Memphis that Jim Butler uses I think, is that who you used? I have talked to them before.
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Old 12-22-15, 03:38PM   #140
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Spec'ing my desired thrust dimension to Adney now. 113m bearing calico'd measures 1.1340 torqued in align-honed studded redoweled block. Pontiac spec from HO's old book says end play .0035 to .0090. I have trimmed the high end abit and am using .0035 to .0075 giving Adney the target of midpoint .0055 (1.1395) . Being a rookie at this I dont know if appropriate. Any thoughts on dimension would be appreciated ... yes it will be welded, then nitrided by Adney and cryo'd and balanced by Paul.
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Old 12-23-15, 11:33PM   #141
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After you get everything done to it get it cryogenic treated to take all the stresses off of it.

It will live longer.
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Old 12-24-15, 06:12AM   #142
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That is already planned ... Paul will do it and balance ... if I can get it machined. May be moving grinding operation to Crankshaft Specialties in Memphis.
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Old 12-24-15, 10:42AM   #143
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Let Paul do it all! You will have a much better result and only have to ship it to one place.
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