283ci stroker?
- Thread starter MRJLB84D
- Start date
ok, i got talking to the bloke who has the 283 stroker
he says its a heavily offset crank, has 302 clevo rods and the block has been notched for clearence. Was built by a ford 250 nut down woolongong way if anyone may know him?
I will be going to check out the motor next weekend (will get pics if i can) as he is thinking of selling it, if i could find a way to get the compression lower to suit the turbo, man wouldnt it be a killer!
As it is now running a 4barrel holley, 12.5:1 comp, stage 6 cam, rollers, twin valve springs, the full works, punched out 287hp threw the wheels...very impressive i thought considering the motor has only done less than 2000km and not full on tuned to perfection.
Will keep you posted when i find out more
he says its a heavily offset crank, has 302 clevo rods and the block has been notched for clearence. Was built by a ford 250 nut down woolongong way if anyone may know him?
I will be going to check out the motor next weekend (will get pics if i can) as he is thinking of selling it, if i could find a way to get the compression lower to suit the turbo, man wouldnt it be a killer!
As it is now running a 4barrel holley, 12.5:1 comp, stage 6 cam, rollers, twin valve springs, the full works, punched out 287hp threw the wheels...very impressive i thought considering the motor has only done less than 2000km and not full on tuned to perfection.
Will keep you posted when i find out more
Sounds like a heroic stroker. I've seen one bloke in an EFI Fairlane try to do one on the cheep without internal mods.This picture shows the results were less than satisfactory! LOL!
Technically, the 6.03" long Clevo 302 rods can fit in the tall 9.38" 250 Non cross flow or 4.1 X-flow block. A good old custom Ross or Precision Chev 305 or Rover 4.6 or Leyland P76/301 Buick stroker pistons with 1.205" deck would fit okay.
One issue is that the 250 crank is already very close to the cam. Ford made some cam mods to clear the crank in 1971, and the cam is already back cut to clear the counter weights, reducing its section width. The cam isa drop forged with some big divits in it, and I'd guess those 302 rods would need a massive curved grind back of some ARP style bolts to fit in there without breaking stuff.
However, if you were to offset grind after welding the crank up to about 2.5 inches with long run weld, you could indded to a massive stroker. After grinding it back to the 2.311" of the 302C or 5.78" long 351C rod, and a full on grind up of the rods bolts, crank case and some carefull work on the camshaft, I'd say 4.097" strok is possible. With a 60 or 40 thou overbore, thats 270 cubes.
To get 283, all you need with 60 thou over pistons is 4.29" stroke, and that means the stock 240 mm wide crank case would be almost 'hyper ventilating'. You'd have to avoid the water galleries, or cut trhough them, weld them up, and then hardfill the block.
Incidently, the Rod ratio with 302 rods is 1.4:1, real bad. The 351 rods, thats 1.34:1. Worse than horrible.
Never mind, nobody said 235 cube Holdens with 221 cranks would be a sucess either. It had a rad ratio of 1.425:1. It was technically an engine on the raggard limit. That over 85 of them were made by a Brisbane engineer, some supercharged with over 320 hp, tells us they were works of art.
I've lived long enough not to be too sceptical. If Poms can take an old A-series 1275 engine out to 1599 cc, then an Aussie can take a 250 out to 283.
Just don't ask for a warranty!!!!!
Technically, the 6.03" long Clevo 302 rods can fit in the tall 9.38" 250 Non cross flow or 4.1 X-flow block. A good old custom Ross or Precision Chev 305 or Rover 4.6 or Leyland P76/301 Buick stroker pistons with 1.205" deck would fit okay.
One issue is that the 250 crank is already very close to the cam. Ford made some cam mods to clear the crank in 1971, and the cam is already back cut to clear the counter weights, reducing its section width. The cam isa drop forged with some big divits in it, and I'd guess those 302 rods would need a massive curved grind back of some ARP style bolts to fit in there without breaking stuff.
However, if you were to offset grind after welding the crank up to about 2.5 inches with long run weld, you could indded to a massive stroker. After grinding it back to the 2.311" of the 302C or 5.78" long 351C rod, and a full on grind up of the rods bolts, crank case and some carefull work on the camshaft, I'd say 4.097" strok is possible. With a 60 or 40 thou overbore, thats 270 cubes.
To get 283, all you need with 60 thou over pistons is 4.29" stroke, and that means the stock 240 mm wide crank case would be almost 'hyper ventilating'. You'd have to avoid the water galleries, or cut trhough them, weld them up, and then hardfill the block.
Incidently, the Rod ratio with 302 rods is 1.4:1, real bad. The 351 rods, thats 1.34:1. Worse than horrible.
Never mind, nobody said 235 cube Holdens with 221 cranks would be a sucess either. It had a rad ratio of 1.425:1. It was technically an engine on the raggard limit. That over 85 of them were made by a Brisbane engineer, some supercharged with over 320 hp, tells us they were works of art.
I've lived long enough not to be too sceptical. If Poms can take an old A-series 1275 engine out to 1599 cc, then an Aussie can take a 250 out to 283.
Just don't ask for a warranty!!!!!
well the more and more i read about it u guys are tottally right, definatly worth investigation and will definatly get pics.
well here is another question then, H beam rods... i want some, where, what brand and i dont care if they chev, rover or out of a holden...to save offsetting the crank etc, i just want strong rods so i can fully boost my motor up!
also, if they stuffing 221 cranks into holdens, has it been done the other way with a 202 crank in a 250 block?? i probobly just made a funny!
well here is another question then, H beam rods... i want some, where, what brand and i dont care if they chev, rover or out of a holden...to save offsetting the crank etc, i just want strong rods so i can fully boost my motor up!
also, if they stuffing 221 cranks into holdens, has it been done the other way with a 202 crank in a 250 block?? i probobly just made a funny!
Get some aftermarket H section rods (Scat, Eagle, or perhaps get them via Aussie company Precision) Specify them with 5.85" length, as used in 400 and 383 Chevies. The Nizpro 4.0 DOHC turbo ran 6.00 or 6.20 " SB Chevy rods.
Use the 2.1" SBC crank pin diameter. Your 250 crank will have to have the journals down sized 26 thou to suit the stock 2.10" Chev item, while the bearing width needs to be slightly increased from 0.845 to about 0.945". This allows you to control the fillet raduis of the crank, should be about 20 thou, and that will ensure you never have a crank problem. Some of the counterweights get reduced during this operation by about 200 thou, but in the process, you reduce weight and gain good strenght gains. If it fits, a later EF crank with its stock damper would be a good option. The 1960 to 1993 Ohv crank has only 8 counterweights, while the EF went to 10, with a special balancer. The XT5/XT6 Holden 3.3's were fully counterweighted engines, unlike ours.The AU went to a big, 12 weighted thick main bearing crank with space for the OHV oil pump. The BA used a Commodore/ Jap style drive.
Buy the H section rods, and buy them 'bushed'. (Not political, Addo
) You may have to get someone to rebush the diameter to 0.9112", as oppossed to the 0.927" pin used in Chevies. The basic rod comes with a 0.984" hole, and you'll have to get the bushes custom made. Noraml Chev or Ford Bushes are about 16 bucks each, but it allows you to run Ford pistons. The stroker Windsor 5.6 bushes are too big, so get some 289 or 302 bushes. Nope, I don't have a part number buddy, but they are out there!
If you don't mind a 56 thou over bore, you can run the beloved stock 305 forged TRW pistons I rabbit on about!
The best ACL 250 pistons could be marginal with more than 500 hp or 16 psi boost, but it has been done with EFI VK Holden 3300 engines in a red Torana XU1 in Street Machine with just a Halteck computer.
Talk with a great race engine builder, and get him a copy of this.
The Holden crank flange has the trust loads taken up at number seven bearing, meaning its much safer to weld up than a Holden crank in a Ford.
The Falcon sixes have thrust loads from the clutch taken up at number 6 and this makes it pretty hard to fit a Holden crank in there. The XT5 3.3 crank has a 2.5" main bearing, 3.25" stroke, and small 1.9" crank pins. Thats a 207 cube engine for no real advantage in performance.
One day, one of your Aussie brothers will put one in a 250 Falcon, and it'll rev to 10 000 rpm, and stitch up Holdens!
Gotta get back to my projects. Talk to everyone, then follow your instincts and then go make it happen, Dave!
Use the 2.1" SBC crank pin diameter. Your 250 crank will have to have the journals down sized 26 thou to suit the stock 2.10" Chev item, while the bearing width needs to be slightly increased from 0.845 to about 0.945". This allows you to control the fillet raduis of the crank, should be about 20 thou, and that will ensure you never have a crank problem. Some of the counterweights get reduced during this operation by about 200 thou, but in the process, you reduce weight and gain good strenght gains. If it fits, a later EF crank with its stock damper would be a good option. The 1960 to 1993 Ohv crank has only 8 counterweights, while the EF went to 10, with a special balancer. The XT5/XT6 Holden 3.3's were fully counterweighted engines, unlike ours.The AU went to a big, 12 weighted thick main bearing crank with space for the OHV oil pump. The BA used a Commodore/ Jap style drive.
Buy the H section rods, and buy them 'bushed'. (Not political, Addo
) You may have to get someone to rebush the diameter to 0.9112", as oppossed to the 0.927" pin used in Chevies. The basic rod comes with a 0.984" hole, and you'll have to get the bushes custom made. Noraml Chev or Ford Bushes are about 16 bucks each, but it allows you to run Ford pistons. The stroker Windsor 5.6 bushes are too big, so get some 289 or 302 bushes. Nope, I don't have a part number buddy, but they are out there!If you don't mind a 56 thou over bore, you can run the beloved stock 305 forged TRW pistons I rabbit on about!
The best ACL 250 pistons could be marginal with more than 500 hp or 16 psi boost, but it has been done with EFI VK Holden 3300 engines in a red Torana XU1 in Street Machine with just a Halteck computer.
Talk with a great race engine builder, and get him a copy of this.
The Holden crank flange has the trust loads taken up at number seven bearing, meaning its much safer to weld up than a Holden crank in a Ford.
The Falcon sixes have thrust loads from the clutch taken up at number 6 and this makes it pretty hard to fit a Holden crank in there. The XT5 3.3 crank has a 2.5" main bearing, 3.25" stroke, and small 1.9" crank pins. Thats a 207 cube engine for no real advantage in performance.
One day, one of your Aussie brothers will put one in a 250 Falcon, and it'll rev to 10 000 rpm, and stitch up Holdens!
Gotta get back to my projects. Talk to everyone, then follow your instincts and then go make it happen, Dave!
