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Pontiac - Street No question too basic here! |
View Poll Results: Are you interested in a new 4" stroke 2.20 journal Poniac crank and hybird 6.625rods? | |||
I'm interested in both the crank and rods. | 22 | 61.11% | |
I'm only interested in the crank. | 8 | 22.22% | |
I'm only interested in the rods. | 0 | 0% | |
We don't need these parts. | 6 | 16.67% | |
The crankshaft we really need is____. | 0 | 0% | |
Voters: 36. You may not vote on this poll |
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#1
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Research Poll on a new 4 stroke 3 main forged crank and hybird steel connecting rod
I'm doing a little research/information gathering for a company that may seriously consider bringing a new forged crankshaft to market as well as some hybird connecting rods that I believe our hobby can really use.
Crankshaft: Forged Steel 4" stroke, 3" Main, 2.20 BBC Rod journal Connecting Rod: H-beam rod Pontiac length 6.625" .980 pin with a BBC 2.20 rod journal This crankshaft would be more feasible to produce as it will fit both those who wish to use longer connecting rods and this hybird connecting rod would allow others to use off the shelf Pontiac pistons in our builds for both 4" stroke and 4.21" stroke combinations. Whether you love or hate this idea or couldn't care less, please be professional and courteous. I'm conducting this poll here because I believe that we are the potential customers and and are far more dignified and sincere than a Facebook group.
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Johnny US Army Retired 1978 T/A 463 Pontiac, KRE 74cc 292CFM D-ports, Lunati VooDoo, V-max lifters, TKII, ATM 850 E85 carb, TCI TH-350 race tranny, 3600 converter 3.73 12 bolt 11.63@116.68mph 1981 T/A 4-speed 406 Pontiac, Merrick ported 6X heads, Comp 270S cam, Crosswind intake 750 Street Demon, 3.42 30 spline Eaton posi street car. 1980 Formula 350 Pontiac back burner project 1972 LeMans 350 Pontiac Last edited by Johnny406; 06-16-2022 at 11:51 AM. |
#2
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If this comes to fruition I hope that the cranks rod journals get made with the lesser width needed for the BBC Rods as opposed to Pontiac Rods so that the excessive side clearance can be brought into spec to stop excess oil that these conversion's always have kicking around.
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I do stuff for reasons. |
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#3
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Ditto that ^ And yes I'd be interested.
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'65 Tempest 467 3650# 11.30@120.31 |
#4
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Am very interested in a 3" main, 4.00 stroke forged crank.
a 2.25 rod journal would however allow to duplicate another offset ground 4.00 stroke build using same rods.
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Buzzards gotta eat... same as worms. |
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#5
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I always liked the 4 inch stroke Stratostreak engines, more torque that the 3.75 engines, but not having the FPS piston speed of the longer stroke engines. That was the platform I used in my last oval track engines.
It seems when the 4 inch forged cranks become available, they sell out first, then you only have the 455 stock stroke, and longer available in forgings to choose from. Not to mention the 421 and 428 engines only were made from late 1961 until 1969 so a much lower production window to pull used cast cranks from too, add to that it was an extra cost option over the 3.75 engines. I have never built one, but always wanted to start with a .030 over 455 block (440), and use a 4 inch crank in it with round port heads, cast iron, or aluminum. Sure you'll have more torque with a 455 or longer stroke, but hooking one of the long stroke engines with street tires is not easy, they just incinerate the rear tires. When I ran autocross, it was always a struggle to hook a 455 car, a 400 was much easier to transition out of turns into a straightaway with out lighting the tires up, and consequentially slowing your lap times. I never did run a 4 inch stroke engine in autocross, but would have liked to. 428s are much tougher to find than a 455 core is, and a 421 buildable core, is like looking for hens teeth. Having a BBC rod opens up a whole lot more rod bearing availability in standard size, and undersized bearings, and rod choices. Definitely interested in a 4 inch crank with rods to compliment it. Be nice if the parts were made here, but that might be a big ask in todays economy. I believe that more 4 inch stroke Pontiac engines would be built if there were more 4 inch stroke cranks available, JMO.
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Brad Yost 1973 T/A (SOLD) 2005 GTO 1984 Grand Prix 100% Pontiacs in my driveway!!! What's in your driveway? If you don't take some of the RACETRACK home with you, Ya got cheated Last edited by Sirrotica; 06-16-2022 at 01:33 PM. |
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#6
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I am considering (mostly dreaming) of doing a 4" stroke (433 ci) for a bit more torque for my heavier car. I would go with a forged crank. Off the shelf forged pistons instead of the costlier custom racing pistons would be a plus. Also same with the rods. The Pontiac H beams rods tend to be a bit more expensive than the BBC. Then again if the added cost of the forged crank can be handled, why worry about a few extra bucks for rods n pistons.
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Frank M. 75 Firebird 68 Firebird 400 RAIII 66 Chevy II 461 Pontiac in AZ |
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#7
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I would have probably gone with a 4" stroke forged crank for my build if it were available.
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70 TA, 467 cid IAII, Edelbrock D-port heads, 9.94:1, Butler HR 236/242 @ .050, 520/540 lift, 112 LSA, Ray Klemm calibrated Q-jet, TKX (2.87 1st/.81 OD), 3.31 rear https://youtube.com/shorts/gG15nb4FWeo?feature=share |
#8
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I hope you get it done.
I sold a Scat 4" stroke 2.20" journal crank for 600$ years ago. Kicking myself for it now. If you could get it done with a fully counter weighted crank lots of people would buy those. In 4.25 and 4.5" too, they would sell IMO. Takes a billet to get that for Pontiacs . You can buy a fully counter weighted crank for a BBC for under 2K. People would pay that for a Pontiac version. |
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#9
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I have been looking for a 4 stroke crank with Pontiac rod journals for a long time. Even considering turning down the mains on a 428 crank .
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#10
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#11
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I would want pontiac rod Js.Tom
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The Following User Says Thank You to tom s For This Useful Post: | ||
#12
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I'm in for Crank and rods. We need affordable Forged slugs for this deal.
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12.24/111.6MPH/1.76 60'/28"/3.54:1/SP-TH400/469 R96A/236-244-112LC/1050&TorkerI//3850Lbs//15MPG/89oct Sold 2003: 12.00/112MPH/1.61 60'/26"x3.31:1/10"/469 #48/245-255-110LSA/Q-Jet-Torker/3650Lbs//18MPG 94oct Sold 1994: 11.00/123MPH/1.50 60'/29.5"x4.10:1/10"/469 #48/245-255-110LSA/Dual600s-Wenzler/3250Lbs//94oct |
#13
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There are readily available 6.635 BBC dimension rods out there that can be used to connect a Pontiac style piston to a crankshaft using a Chevy rod journal. The Pontiac style piston has to be honed for a .990 pin and it opens up your choices for a specific wrist pin for the job at hand.
Years ago crank suppliers couldn't sell the 4" stroke cranks so a lot were discontinued. Nowadays the interest for the 4" crankshafts has seemed to increase. |
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#14
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There is a 4” stroke forged crank in my near future. I’ve noticed here and in the Pontiac community in general that 4” stroke engines get a lot of support - but often people seem to change their plans when the crank isn’t available.
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#15
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You might want to update the title of this thread:
"Research Poll on a new 3" stroke 4" main forged crank and hybird steel connecting rod" And, yeah, good idea to get this crank made. It's still my favorite stroke. Not so much torque that you can't hook it up, and also likes to rev, which is where the HP comes from. My 434 sounds and runs awesome at 6500 rpm! |
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#16
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Quote:
Thank you for your input and for all of those who have chimed in. I think it would me for an ideal bracket motor and even a real good power adder combo.
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Johnny US Army Retired 1978 T/A 463 Pontiac, KRE 74cc 292CFM D-ports, Lunati VooDoo, V-max lifters, TKII, ATM 850 E85 carb, TCI TH-350 race tranny, 3600 converter 3.73 12 bolt 11.63@116.68mph 1981 T/A 4-speed 406 Pontiac, Merrick ported 6X heads, Comp 270S cam, Crosswind intake 750 Street Demon, 3.42 30 spline Eaton posi street car. 1980 Formula 350 Pontiac back burner project 1972 LeMans 350 Pontiac |
#17
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You didn't see it: your title says 4" main and 3" stroke.
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#18
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Edited the title.
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#19
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I also typed 4.20 instead of 4.21 stroke (455 Pontiac) on the first post as well.
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Johnny US Army Retired 1978 T/A 463 Pontiac, KRE 74cc 292CFM D-ports, Lunati VooDoo, V-max lifters, TKII, ATM 850 E85 carb, TCI TH-350 race tranny, 3600 converter 3.73 12 bolt 11.63@116.68mph 1981 T/A 4-speed 406 Pontiac, Merrick ported 6X heads, Comp 270S cam, Crosswind intake 750 Street Demon, 3.42 30 spline Eaton posi street car. 1980 Formula 350 Pontiac back burner project 1972 LeMans 350 Pontiac |
#20
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The best market positioning would be to make enough meat on the forging that it could be machined to a range of strokes and rod journals.
FWIW, Eric
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"Everybody has a plan until they get punched in the mouth" noted philosopher Mike Tyson Life begins at the end of your comfort zone. The mind, once stretched by a new idea, never returns to its original dimensions. |
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