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#61
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double secret........... Bwahahahahahahaha. No they are available from just about any engine shop source.
That's funny. |
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#62
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Cliff,
Nope. It seems okay when welding in weight for balancing. That portion of the crank isn't under so much stress. As for welding the thrust up to use a large journal crank in a small journal block, I've seen good and bad. IF (big IF) the crank guy goes through the entire process correctly, preheating, and spray-welding, it has been successful on many occasions. I've also seen many Pontiac cranks come out of block in two pieces, broken right at the radius on main #4. We have also seen, from companies like Standard Crankshafts and CRI (Crankshaft Rebuilders, Inc), where the cast crank came out of the "kit" box at standard. These ALL fail magneflux at the radii due to the welding. Had a 400 Ford last year, with nearly 70K miles on the rebuild, start knocking. Took it apart, and crank was broken right behind number 1 main. Stuck another "kit" in it (.020/.020) and it's over 100K now. For those that still don't understand why the racers want the BBC journals more than those that don't, I can't help you anymore. Based on current attitudes and the performance "environment", I doubt the 3.75 stroke will sell very well no matter what rod journal it has. The current thinking is "bigger is better", so the vast majority will be at least a 4.25" stroke. Thankfully, the 4" stroke is on everyone's "list". Jim |
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#63
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__________________
If you cant drive from gas pump to gas pump across the map, its not a street car. http://s207.photobucket.com/albums/b...hop/?start=100 |
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#64
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Quote:
I'm not making this too serious,but it does bother me that some folks "on high" dont seem to have an open mind on this topic,and only want to look at it from one POV,and that's their own POV,and are not very responsive to the wants of those who spend their hard earned money on these projects. Still the idea of a .050" "thicker" rod bearing is'nt instilling any deep confidence in my mind,,,sorry... Please do explain how that bearing will add strength & durabillity to any 700 hp 3.75" stroke combos? Is that not a "band-aid" approach,if it were'nt why not build all motors that way??? And still no comments on all those stock rod journal motors ya'll have built thru the years... So,do you guys in fact think/feel/admit those stock rod journal builds you've done for customers thru the years were/are all junk,worthless as "race" motors because they're crippled with the stock pontiac rod journal dimension? Would you now refuse to build one for a customer if that were his wish,or those were the parts he already had on hand. How do you guys explain all the many "race" engines out there in the past and as well as nowadays that apparently run just fine with the stock rod journal size??? Do tell,,,enquiring minds wanna know... I agree the 3.75" stroke cranks are a tough sell these days,that is EXACTLY why I said making them even less marketable from the get-go by offering them only with a bbc journal was a boneheaded move,when just a little bit of thought,and understanding of the market for such a piece suggests the obvious market for that 3.75" forging is for the stock journal "replacement" crank first,and the bbc "race" journal secondary to that. Lots of "commercial" grade rebuilds of engines like the sbc and such get forged cranks in them,even when they're not slated to make 700 hp,does it make more sense for a 400 hp 383 cid sbc get a forged crank than a comparable 400 hp 400 cid pontiac? Like I said,the logic here is'nt that deep,or hard to grasp. Folks often like to add some extra margin of quality when replacing a piece like a crank,why not use a forging,if I gotta spend some amount of money on a crank anyways,a little extra premium for the forging would be no biggie really,as long as I dont hafta fork out a bunch more cash buying or replacing parts I already have,or go thru the added trouble or time involved to find a competent crank shop or machine shop to do this extra work to get it in the motor. Not all that different from the cast/forged rod decision making process. Dude has his 8 cast 10/10 cranks for sale in the perf. parts forum for $200.00 ea.,now a fella needing a "stock" 400 replacement crank sees that and goes hmmm,it would likely cost that much to turn my core 400 crank and get it to spec anyways,,,but wait,,,Ohio crankshaft has a brand spanking new 3.75" stroke forging for $575.00,,,whoa now I gotta think a second,,,that's only $375.00 more,,,(wheels turning...) Is the picture getting clearer here,most guys would consider that reasonable cash outlay as long as it does'nt mean an a$$ load more $$$$ or grief to get the crank in the engine. Those 3.75" forgings should have made the cast 3.75" cranks worthless IMO. Not the other way around.
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#65
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Ok, since you brought up not liking to use .050 thicker bearings.
Which can handle the heat better. And why. Standard or thicker? Not being a m.a. Have my own theories. Just picking an experts brain ![]() BTY, if i was going to buy a crankshaft to go fast, it would be a 4" with 3" mains.
__________________
If you cant drive from gas pump to gas pump across the map, its not a street car. http://s207.photobucket.com/albums/b...hop/?start=100 |
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#66
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Sceamingchief
If there is such a market for these 3.75 Pontiac journal cranks why don't you profit on it. Find some investors, pitch your sale , and sit back and let the money role in. If that doesn't work, morgage your house , tool up , and start forging them. I'm guessing these companies making the cranks may know a little more than you and I both about the "market". However, If you follow one of my 2 ideas you will end up with the crank you want, not to mention broke and homeless. Good luck
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#67
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Quote:
Actually I was just supplying info if others wanted to use a .050 bearing. For everyday use. Not a problem. Under load or race conditions, I wouldn't recommend it. I don't really see what people want in a $600.00 400 steel crank with 2.250 journals. But that's me The demand would be less then 10% of the totsl crank market. 99% of those 400 builds are midly stock or numbers matching anyway for my shop. A cast crank will take 650hp anyway. How many broken 400 cranks has anyone seen over the years. I have never personally seen or heard of one on this board in 8 years. The rest I take their 400 blocks and turn them into either 4", 4.210 or 4.250 deals anyway. I don't see a big market for 3.75 cranks, especially when the 4" in a IA2 is the same as a 454. And will rev to 8500 nd live. Installing a 3.75 would be like the old 427 deal of the 70's. This will go on untill the cows come home and don't see an answer or solution. Unless someone puts up the money for this crank. Period. Let the journal wars continue. LOL. |
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#68
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The easist is the 4.350 bore with a 4.250 stroke for people not wanting to get into heavily modified heads, etc to make the 535 work efficiently. Ya can twist that combo (505) 7200 and not break a sweat. |
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#69
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Jim, we've never tried to weld one up for the small 3" journal, but have welded quite a few turned 455 cranks that had too much thrust clearance. The shop I send them too has a machine that does it, with a special process. I refuse to run one with more than about .008" thrust, .004-.006" is where I like them, so we have them welded up, costly, but I sleep better at night!.....Cliff
__________________
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), |
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#70
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"If people are determined to use Pontiac size rods. I can supply .050 rod bearings for the BBC rod journal size." So in reality you offer a .050 undersized PONTIAC BEARING that fits into a pontiac rod that will fit on the chebby rod journal Pontiac crank. In my mind the Pontiac bearing would work well as the actual bearing material is exactly the same thickness just each bearing shell has a .025" thicker backing material vs stock. This is for street cars. If the car was raced at all I would use the 6.635 Chebby rod and the chebby bearings as they are a much better bearing material and there are a lot more Chebby bearing offerings. Tom V.
__________________
"Engineers do stuff for reasons" Tom Vaught Despite small distractions, there are those who will go Forward, Learning, Sharing Knowledge, Doing what they can to help others move forward. |
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#71
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My stock journal,TRW piston 455 is still running fine.11.20s on pump gas NA.It would be great if the .3.75 forging was a Pontiac journal so if someone wanted to turn it down to BBC size they could if they wanted to.
But I am happy that it is even offered in BBC rod bearings.The only real extra costs is the pistons and you end up with a lighter stronger one anyway.Pay the 575$ for the Ross(or whatever "good) piston you want and be done with it.The 6.8 rods are not expensive,cheaper than 6.625. So you pay 200-300$ more up front and you end up with a 400 with stong light pistons(better)6.8 long rods(better) and thinner rings(also better) It sound like a win win to me with not that much more up front costs. If I were to build a good 400 that is how I would do it as opposed to one with TRWs and 6.625 rods. |
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#72
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#73
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If I was road racing I would use the 4" crank and a 4.350 bore. Better off the corner deal. I have built a few road race combos. All 428 style. All run great. t would run 7000 no problem. But I would get into some serious internal components.
It would be a 476 cu.in. BBC style combo and build along those lines. Just need a good flowing head with great mid numbers and the right camshaft choice. I don't have any info on the durability of the aluminum block. I think the Jury is still out on that deal and long term heavy duty useage. You would need more gear. And I don't think a tremec will hold up. |
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#74
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EMRA ST-3 class, probably the corresponding SCCA class as well (but I can't remember it off-hand at this point). To run SCCA reasonably competitively, I'll need 17" rims with good racing tires, that's about the only place the 2 classes don't line up. I'm hoping to make a time trial or two at the end of this year and depending on competitiveness, a full season of time trials next year and actual racing the following. The engine rules dictate you have to use engine parts available in the generation car you are running with max 10.5:1 comp unless stock was higher (headers allowed) - best bet for road racing is a 400 with raIV cam and either SD or raIV heads and the maximum allowed compression (10.75 would be allowed on the IV I believe). I don't feel a 455 will last as long as a 400, or make any more power as the limit will be airflow in either engine case (no head porting allowed), so the 400 is the preferred option. As the time trials will be about 20 laps per day and races even more, I would like to ensure I don't puke out the internals or wear the engine out quickly. For the end of this season I'll be running the current stock bottom end combination but I'm under no illusions that it will last long under the abuse it will take, so I'd like to start building a replacement over this winter with forged internals. I'm toying with the idea of running NEI which is based solely on rwhp to weight so the engine part limitations would be out the window...Some sponsorship and prize money that EMRA doesn't have but I will see where my car ends up. I like the EMRA class better as the competition is more interesting and more along the lines of keeping the car stockish (looking at least), but we'll see. |
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#75
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Sounds alot like the rules for Street Prepared in SCCA autocrossing. They would allow alot of changes but no cam change-I thought that was weird, cam change bumps you into the race Prepared classes.
They can be picky in tech also. Saw a Vette get disqualified in stock(and stock IS stock) for a shim on the rear spring being in the wrong place.
__________________
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 [email protected] 1964 Impala SS 409/470ci 600 HP stroker project 1979 Camaro IAII Edelbrock head 500" 695 HP 10.33@132 3595lbs 1964 Corvette Coupe 327 4 speed |
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#76
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I think one thing that hasn't been mentioned here about the 3.75" arm forgings-
3.75" cranks, If nothing else, it gives those interested in Pontiac power another option to build. Some just want to build a smaller motor. A cubic inch to weight class as an example ( drag racing, Bonneville), a blown class where you can run lighter with less inches and still make power. Pontiacs have traditionally not ever been in these types of classes. With the availablility of more good parts, this may become attractive to some. Of course, a 3.75" arm will be for a limited market but, it is there. A blown 390"-420" or so Pontiac engine could have some real potential in comp eliminator, bonneville or? The shorter arm is also attractive for endurance applications. Then again, the 287-370s, with their forged cranks have potential too in modified classes. Just food for thought Steve Barcak www.pontiacheaven.org "Real Pontiacs only...no corporate nonsense!"
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Hundreds of Pontiacs in Az "Real Pontiacs only..no corporate nonsense!" Facebook- Pontiac Heaven Hosting- 23rd annual Pontiac Heaven weekend- Phoenix pending due to covid Pontiac Heaven Museum in process Phil 2:11 |
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#77
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#78
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"Dude i ask because i whant to at least be equal to this car!!!!! chek this site out......." You don't have a snowball's chance against "Big Red" with a Traditional Pontiac engine. I know the car well. He could start a business just selling the oil coolers he has on that car. Tom V.
__________________
"Engineers do stuff for reasons" Tom Vaught Despite small distractions, there are those who will go Forward, Learning, Sharing Knowledge, Doing what they can to help others move forward. |
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#79
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Last edited by roadrage david; 07-21-2007 at 07:28 PM. |
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#80
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Who told you those numbers?
Do the math on what hp it takes to run 230 mph in a camaro body style. Tom V.
__________________
"Engineers do stuff for reasons" Tom Vaught Despite small distractions, there are those who will go Forward, Learning, Sharing Knowledge, Doing what they can to help others move forward. |
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