NO it's a 173 red and it's how i got it. OD prefix
Has been sonic tested so i can only assume it's good.
Was build for a turbo project and block was chosen for its think walls.
It is 91.86mm which is smaller than stock 186 and 202.
Something tells me this block was chosen as it had a larger core....(HP 179x 186 and 202 all have the same core)
Why cant a 173 have the large core as well.
Well you might get close to 300hp with a rrv limit of 5500.prob a bit less.Being a stroker,its inherently unsuitable for high revs anyway.6500 would be a realistic limit to retain good reliability.5500 wont even work up a sweat.
Maybe a custon grind cam specific to the stroker
would be ideal,but off the shelf grinds for the regular sixes can give excellent results.You might try adjustble timing gears as advancing the timing will work a little better on the stroked motor.Due to the bigger cubes.you need to remember advertised power bands will fall by maybe 1000 rpm when installed in the stroker.You really need 50 thou duration of around 240 - 250 degrees to make good power at 5500.The old waggot 104 seems to work great,but im not sure if u can still get them off the shelf.Otherwise try camtech.Personally never been impressed with crow cams.Also u can run 1.6 rockers without incurring a lot of stress.due to the lower revs of the stroker.You will not need quite as much spring pressure as you would in an un stroked motor.
Basically the head is always the limiting factor with the power,so you need a good porter,unless you run a j zed head which flows well out the box.
Both the 9 and 12 port can give similar flow,but the 12 port should give more torque,and is probably preferable if you run webers or dellortos.If your just gonna run a holley,a 9 port will work just as well and is maybe less prone to cracking?Of course theres the 12 port alloy which saves you 20kg and will potentially flow a little better than factory castings.
And you should maybe run a bigger damper on the crank.A main girdle doesnt hurt.Not sure how they fit with the stroked crank?
Maybe consider custom headers.as the off the shelf ones are all 1.5 primaries.You might pick up a bit with 1 5/8 primaries,but its a fair bit of expense to get them made.2 1/2 in collector is beneficial once you get up around 300hp,2 1/4 is starting to restrict flow at that level.
Im just wondering what lets go if you oferrev strokers?
Rods?
Crank?
Pistons?
Block?
Why would a 9 port be less prone to cracking?