306.5in stroker

[amcinstaller]

hasnt the difference in strength been discussed many times as well? unless i missed something, both cranks were supposed to be identical in strength.

[ARH]

What KOH team are you building this for? I'm not familiar with Heartland Offroad, but I'm thinking Midwest?

Oh, and pictures of the motor build?

[heartlandoffroad]

The eight counterweight crank and 5600 rpm? Maybe you should read the "max rpm of jeep engine" thread.

I don't need to read any thread to know the max RPM of a Jeep engine. I've built several strokers with this crank and have never had a breakage problem. In fact my personal stroker is a 4.7 turbo that makes 437hp and 620ft of torque and shift it at 5800 all the time.

[heartlandoffroad]

What KOH team are you building this for? I'm not familiar with Heartland Offroad, but I'm thinking Midwest?

Oh, and pictures of the motor build?

They are in the LCQ Alan Grady and Thomas Grady from Rockford Ill.

I'm located in Troy Mo. we've been here sense 1996

[heartlandoffroad]

I for one will be real interested to see the torque curve of such big ports. 280CFM is 30 more than I've seen from any other head porter on an iron head, and 200 CFM exhaust is just insane... Did you get into the epoxy to get that kind of flow? Did you hit any water jackets.

Accually I didn't have to make it much bigger but I did work for a LOOOONG!!! time on the runners and played with the seat radius allot so to keep the speed up. The piston demand on this engine is going to be very hi with it being a 4.200 stroke so I'm hoping air velocity will still be hi to keep the low end torque up at a lower RPM.

[1bolt]

What cam specs are you going with?

[SIXPAK]

Hey heartland, we had the same hopes when porting my current head but lost velocity. Ended up going back in and adding epoxy in some non critical areas to regain the TQ. It did not end up hurting the flow numbers at all.

[heartlandoffroad]

Bullet built me this cam

------------------------------------intake--------exhaust
Duration at .050-------------------236------------242
lobe lift---------------------------.3400-----------.3400
separation----110---------------op---cl------------op-----cl
timing events at .050----------12---44-----------55-----7
duration at-------.006-------------282---------------292
gross valve lift--------------------.544--------------.544
degree intake lobe to----------------------106

Here is a few pics I'll have some more soon.

[Alex22]

Excellent build.

I wish I had the budget for custom rods, about how much did those run you and if you don't mind sharing, what is the actual rod journal size?

~Alex

[heartlandoffroad]

Thank you for the compliment.

I believe the rods are 1300.00 a set.

The big end size is 1.771 with a 1.117 width

[6TIME]

Wow! Very impressive build. I'm anxious to hear about the dyno results of this motor. Keep us informed!

[Alex22]

Cool. We have been using the Honda Civic rod sizes on a lot of our road race 289 and 302 Fords.

That is a lot cheaper per set than I had expected for the rods considering their production parts are about 800 per set.

[SilverXJ]

Impressive. I have heard a lot of people use honda rods and the like on V8s, but not thing on the I6 until now. Good luck and keep us updated.

[Plechtan]

Well I looked around, and you can get a 5.9" rod for a MITSUBISHI Eclipse ( 4 banger) that has a 1.115 BE width ( jeep= 1.060 be) and a BE diameter of 1.771. so if you wanted to offset grind you crank .3", you could use these rods and they would only cost you about $100 each. It does use a .826 floating pin, so you would need to go with custom pistons, but at least you would not need custom pistons and custom rods. Custom pistons at about $100 each is better that custom rods at more than $200 each.

[gremlinsteve]

my kind of build.. ill be watching for the end results.
nice cam specs also.

have you put any thought into cryo treatments and or at least running the parts through polydyn and get the coatings?

steve-o