Jeep Strokers

A cast steel crank may be closer than you think. I will post up info as soon as I have conformation from the manufacturer.

The 12 counterweight cranks are made from nodular iron, which is why I have one to use on my build.

~Alex

If you are working on a crank, it shoudl be around a 4" stroke. 2.1" connecting rod journals, the proper width for chevy rods.

I personally had nothing to do with the development of it but know someone who was. From what I heard its just a cast steel 4.2 crank, not sure how many counterweights or if they changed the stroke.

~Alex

I guess the last 4.2 crank was made about 15 years ago, so it would not be bad to have a source for new ones, but jeezzz, if you go to all tha trouble, you should at least improve it a little.

Plechtan wrote:I guess the last 4.2 crank was made about 15 years ago, so it would not be bad to have a source for new ones, but jeezzz, if you go to all tha trouble, you should at least improve it a little.

LOL it depends where more demand is, in the rebuilders market looking for drop in replacements, or the aftermarket that's looking for bigger displacement.

I will be ordering custom rods for my engine, The will be 6.2" long, the be width and te width will be 1.060 They will have a be bore for a 2" journal, and the top will have a .927 bore for a floating pin.

The 2" bore is to allow more offset grinding of the crank. They will not work with Jeep pistons, custom pistons would be required. I have prices between $200-$225 ea for the rods, but the price would come down if they were ordered in quanity. I would like to get the price in the $150-$175 range each.

So if anybody has a interest, let me know. Delivery is 10-12 weeks!

Alex22 wrote:A cast steel crank may be closer than you think. I will post up info as soon as I have conformation from the manufacturer.

The 12 counterweight cranks are made from nodular iron, which is why I have one to use on my build.

~Alex

Its actually a little further away than I had thought. It was supposed to be out for the PRI show, but the companies casting and forging plant in China was shut down for over a month because of the olympics and they lost power for another few weeks because of an earthquake.

Did the connecting rod company give a price structure for a group buy? and are you going to be using the 2.100 rod journal size or are you going to a 2.000 or even a 1.900? That would get a little extra stroke out of these.

~Alex

I am going with a 2" journal size on the crank. I plan to offset grind the crank to get a 4" stroke. Since the 258 crank is almost 3.9" going with a rod that is .100 smaller ( in round numbers) should let me get to 4" without a problem.

According to Lee at Hesco, the later 4.0 blocks can be bored to 4" without a problem. Well i thought i would give it a try, i had 2 blocks and here are some of the sonic test numbers 0 is the front of the cylinder, 90 is the passenger side, 180 is the rear, and 270 is drivers side. First number is is top, second is middle third is bottom.

Casting 53010328AB

Cylinder# 0 90 180 270
1 .281 .306 .154 .291
mid .195 .315 .108 .269
bottom .814 .334 .115 .295


2 .198 .325 .180 .252
mid .182 .288 .150 . 250
bottom .189 .318 . 170 .281

3 .166 .342 .188 .295
mid .144 .309 . 158 .275
bottom .169 .511 .172 .305

4 . 188 .325 .148 .305
mid .177 .301 .136 .281
bottom .200 .388 .159 .313

5 .190 .327 .180 .285
mid .171 .301 .163 .254
Bottom .176 .622 .190 .280

6 .189 .350 .263 .280
mid .146 .321 .223 .238
bottom .182 .576 .313 .272


Casting number Casting 53010327 AB

1 .223 .226 .173 .261
mid .186 .236 .144 .227
Bottom .242 .268 .159 .285

2 .162 .284 .147 .308
mid .163 .284 .122 .244
bottom .145 .262 .201 .269

3 .152 .176 .185 .314
mid .133 .255 .141 .269
bottom .245 .260 .163 .274

4 .140 .202 .218 .360
mid .141 .202 .155 .272
bottom .169 .318 .169 .361

5 .161 .227 .182 .303
mid .134 .231 .155 .247
bottom .154 .261 .169 .275

6 .144 .225 .278 .284
mid .136 .258 .203 .242
bottom .178 .249 .231 .276


we wanted to have a .09-.10 minimum cylinder wall at the thinnest point. It looks like both castings have plenty of meat on the sides of the cylinders, but are a little thin front to back. The 328 casting is generally thicker, but has a thin spot in the center rear of the #1 cylinder. To get to 4" we have to remove about .062 per sides of the cylinder ( .125 on the diameter) We ended up using the 328 casting and sleeving the #1 cylinder, we did break through a little, but i think the sleeve has plenty of support. Both blocks had almost no wear on the cylinders, you could still see the hone marks.

I will look for another 328 block to see if i can bore it to 4" without sleeving it.

Do you plan on using any ceramic sealer on the bore that broke through or are you going to move onto another block all together?

Yes we will be using some sealer. I was wondering if anybody else has sonic test numbers. I believe the 327 block is an 00 and the 328 is a 2003. I think i saw another thread were somwbody else was looking for a block to bore out to 4" and had check 10 or so blocks.

I found the thread http://www.jeepstrokers.com/forum/viewt ... lit=blocks.
Based on what is says there, the 328 casting is thicker than the eariler castings. Thrust side numbers over .3 . It should be noted that the thin spot on the front and back of the cylinders is only 1/2' wide or so. If you look between the cylinders through the freeze plug, you will see where the have made a flat on the cylinders.

I remember reading a cylinder wall thickness discussion and iirc, the renix blocks had the most material.

I don't think any of the older blockd had more than .250 on the thrust side. The 328 block consistantly had .3 0r more, so if you did take .060 off you still would mave abouut .250 left.

A while ago i asked Hesco to provide a Aluminum head with 2.02 intake and a 1.60 exhaust, they refused, said that they only will modify heads for an engine they are building. Well, Lee did offer to sell me a bare head without seats that i could modify myself. Putting seats in an aluminum head seemed a little scary to me, so i Asked again if they would supply the head with oversize valves and combustion chamber modifications to unshroud the valves. Well he came back with a quote of $2,910.00 This includes stainless steel valves ( LS6 style) springs, retainers, combustion chamber modification and flow bench testing. A little steep, I can by a pair of an aluminum heads for an AMC V8 for $1,600.00 and that engine went out of production in 1991!
If i just purchased the standard aluminum head for $2,000 then tried to open up the combustion chamber and maybe put slightly larger valves in to it Then flow bench test it, I may end up a little cheaper, but if i screw up the head I am out $2KA, plus i would not be able to get the 2.02 and 1.6" valves in.
The sides of the combustion chamber would be opened up to a 4.030 diameter, this is the same size as the victor head gasket. The Engine will have a 4" bore, so I am hoping to get some great flow numbers.