Milled head turbo'd 250 update

[fast64ranchero]

Well no pics yet but I'll give you all some motor info, the head is still at the porters should have some flow numbers in a week or two, the bottom end is coming along slow had to ordered a diff set of rods for it, which is holding up the crank from being offset ground the engine will end up around 269 inch's and if any of you want to try and build the same motor I'll give up the needed info, my motor has manley 5.905" (Mitsubishi 4G63B 93 and up) rods, you could get by with stock rods at a low boost level, the crank will be offset ground to 4.1 inch stroke, maybe 4.125" we'll see when it's done, pistons are on hold till the crank is ground, this motor will have a terrible rod ratio, but R/A has little effect till 5500 rpm or so, now if you want you could go about this alittle diff. one could use Jeep 4.2 rods stock or Eagle makes H beems 6.150" which will have a better RA 1.56 or so, and have pistons made or, Manley also make the Mitsubishi rods with a 1.771 big end, which means a stroke of 4.2 could be done, I choose the 1.88 big end rods as I am concerned with that small of a rod journal on a cast iron crank under 15lbs of boost, well there you go that's it, for now I'll post pictures when I get my parts back,

 

[ASMART]

What issues have you found while looking at rods? What details are to be looked at when you decided on these rods? What about width, etc.

 

[fast64ranchero]

when I researched rods I had to look at big end width and big end size, I want a smaller rod journal size, (for offset grinding the crank) stock 250 rod width is .990 so you need a rod that is as big or a tad bigger, too big and the crank grinder will get fussy, (messes up him grinding stone) so this left a couple of options, the 93 and up Mitsubishi rods, big end is 1.038 wide and 1.889 in diam. or the 4.2 jeep which is about the same width but big end diam. is 2.095 (not much left for offset grinding) I really don't care about small end sizes due to the fact pistons will be made, one might also look at the chevy LS1 rods, oops I forgot you have to get a rod with 0 offset so most V engine rods are out of the question, the LS1 is the only V engine I know of with no offset in the big end, so look for str8 4 or 6 cylinder rods, pre 92 Mitsubishi rods have a wider big end but could work so all you guys wanting to do a low dollar stroker find some 93 up 4G63B stock rods and have your crank offset ground (mine cost $275 for the grinding) and have some pistons made.... later Walt

 

[ASMART]

Wher edid you get all of your rod deminsion info? I hope you are going to tell me on the web somewhere.