Just a line to introduce my self . I a currently a crankshaft machinist living near Detroit Michigan .. I do all kinds of crankshaft repairs and strokers for odd ball combinations . I am just finishing a stroker stovebolt project for my Dad's 47 chevy coupe .. as soon as I can figure how to post pictures I will .. I also have video of it on the dyno .. I think we pretty much doubled the horsepower , and I am sure that the transmission in the old chevy will not be up to the task of getting it to the ground ... I wish we had more time to run a few more tests because we ran it from 2500-4500 and max torque was at 2500 , that gets me to wondering how much more it was making below that ........ we also made a progressive linkage for the 3x1 carb setup that worked slick , the video shows it working real well ... if anyone is interested in specifics I will post what I can and will try to figure out how to post pictures and video .. for now I hope you all have a Merry Christmas and a happy new year ... awbrown
Welcome from Minnesota! Good to have machinist types around on the board! What size "stovebolt" did you start with and where is it size-wise now? Thanks, Tim
Well , the stroker stovebolt I did for my dad is based on a 261 block with an 848 235 cylinder head... I bored it to 3.905 , only because it had rust in one cylinder and the shop boring the block said it didnt clean at 3.875, though I suspect after talking to the machinist that he may have made a mistake .. He really wanted to sleeve the block , but I was certain it should have cleaned a lot sooner , he was relieived when I told him to go to 3.905 ,though he argued I could not get pistons ..We did sonic check the block so I was certain it would have enough meat to work well.... I used a 7 inch H beam rod and used an .827 wrist pin ... I offset ground the crank to a 2.00 pin for a stroke of 4.220 , I would have stroked it more but the crank was already ground undersize on the rods...The pistons were made by Diamond and have a small dish and a valve notch for a final compression ratio of 9.0 to 1 and final displacement of 303 cubic inches.. the head was just cleaned up in the bowls and machined for positive seals.. the short sides were radiused and the ports smoothed but not polished .. I ran a 3x1 setup on a offy manifold , all rochesters, and surprisingly enough they did work well on the dyno .My friend made a custom progressive linkage and I am hoping to post the video , it worked slick ... It has fenton cast headers and we ran 2 1/4 pipes .. a GM HEI replaced the stock points ignition system ....The cam is a comp cams 252/264 213 @ .050 Intake 220 @ .050 exhaust both have .435 valve lift ... On the dyno we ran it from 2500 - 4500 rpm and that may have been a mistake because it made it's max torque at 2500 rpm with 340.8 ft-lbs of torque , it more than likely made more below that , we just never thought to test it lower in the rpm range ... The horsepower ran from 157 @ 2500 to a high of 229 @ 4300-4500.. Our goal was to double the stock horsepower of the original engine ,and according to the old article by mcgurk in the 1955 issue of hot rod we did just that ... If I can figure out how to post the dyno sheet and the video of one of the dyno runs I will ...
it's actually a 48 chevy coupe with a 47 grill .. The story goes that he wanted one real bad back when he was in high school ...He stopped by the house with one he was trying out from the local used car dealer , the dealer was less than reputable and his father said no ... and so all these years he has wanted one .. now being 68 years old he found one and has had it at a body shop for a few months .. you know the story , quoted one price and it was double when he picked it up ....anyways I have a feeling the stock 3 speed tranks will not last to long with the torque the new 6 has so I suspect he will be updating both trans and rear end in the future .. thanks again to all those who have shown an interest in this project .. have a Merry Christmas and a Happy New Year ...
im new to h.a.m.b too and was thinkin about leavin the i6 in the car but was wondering if i can get the stuff to mount ac to the block ? want to do some long crusies with the wife and kids which aint gonna happen without a little cool air. it will be in a 53 chevy 150 and i would like to keep it in a 50s hotrod look. what ya think?
Well sometimes I think I should have been a chiropractor, seems they only work 3 days a week and I would love to have 3 days a week to invest in my hobby ... in hindsight I could have done this stroker cheaper , but not any better ... I use custom pistons in most of my odd ball stroker motors, and I just fell into the rods they may be over kill but I think they are cool , years down the road someone will open up that beast and say "what the heck are these "? next time I will use a bigger cam to try and tone down the torque just a bit .. I still think it will be quite a ride in that ol' 48..
I'd say 229 hp out of a normally aspirated bored and stroked 261 being fed by three little ports is pretty honorable--enough to ice most flatheads, anyway. You're right about the transmission, though; that engine will shell it like a peanut.
I posted the video on youtube of the last dyno run showing the progressive linkage working .. we loaded it at 2500 and pulled to 4500.. I wish we had pulled it at 2000 I think it would have been interesting .. it made 340 ft lbs of torque at 2400 and dropped off from there .. Wondering if any one has any dyno runs of similar stovebolts ?? heres the link .. see ya Adney http://www.youtube.com/user/AdneyBrown
The Jalopy Journal
