Jeep Strokers

SilverXJ wrote:

RenoF250 wrote: They don't, United Engine and Machine own KB, Silv-O-Lite, and Icon:
https://www.uempistons.com/

Your kidding, right? Maybe I should have said the same company that makes the KB pistons makes the silvolites.

I have the IC944s in holes that are 0.0035" over and I do not hear them when cold.

Then they haven't been cold enough or you can't hear well.

They supposedly used an alloy that expands about the same as a hyper so they do not have the noise of a regular forged.

They are made of 4032 and it does not expand in the same manner as the hypers (or lack there of)... if it they did you wouldn't need .0035" clearance.

charley3 wrote:How about 4032 alloy pistons with long rods?

The KB 944s are 4032 forged pistons. Same deal.

I read at Wiki that 4032 alloy is for performance hyperatic pistions that have 11% silicon in them,

4032 typically has 11% silicon content. Hypereutectic is around 16-19%. 4032 is not hypereutectic. In simple terms Hypereutectic meand more silicon above the eutetic point.

So the 4032 alloy is kind of a slightly hyperatic piston,

NO.

What 4032 alloy piston options are there for use with long rods?

KB 944/ 945 or any other custom piston using the 4032 alloy.[/quote]

?? I was not responding to your comment, not sure why you seem to be taking offense. I just wanted him to be clear where they came from.

I think you are right, they are 4032, Summit says 2618 and I did not check.
http://www.summitracing.com/nv/parts/uem-ic944-030

They have only been down to 60 or so no winter temps yet.

RenoF250 wrote:I think you are right, they are 4032, Summit says 2618 and I did not check.

Very early versions were 2618. Like the first batch years ago. After that they are 4032.

They have only been down to 60 or so no winter temps yet.

60 isn't cold.

What I'm after is a naturally aspirated stroker that will last as many miles as possible with minimal maintainance. I'm looking for reliability and longevity. Performance isn't a concern to me because any stroker will have enough performance for my needs.

Which would be most reliable and last longest? A short rod with some brand of hyperatic or Silvolite pistons; or a long rod with 4030 forged pistons?

Also, I'd like to avoid piston slap when engine cold. Seasonal temps here vary here from 8F to 100F. I'd like to be able to get in Jeep in Winter and cold start it and idle 30 sec or less, then drive off.

So what piston/rod arrangement would best accomplish my goals?

Stock jeep pistons even rattle at 8f if you idle 30 seconds and drive off which I highly discourage with any engine, and the skirt rattle with the forged should not be a concern the forged piston will take more skirt rattle without damage than any cast or hyper piston will. Either way you should always let your engine idle at least one minuet in summer or 5 in winter at the minimum

sly-jeeper wrote:Stock jeep pistons even rattle at 8f if you idle 30 seconds and drive off which I highly discourage with any engine,

The forged piston rattle is much louder due to the extra clearance than even a cast stock piston.

Either way you should always let your engine idle at least one minuet in summer or 5 in winter at the minimum

One minute sure, I wouldn't go 5 minutes unless you are revving it at times. The cam is splash lubricated for the most part and its getting very little oil at idle.

Even with a fairly mild cam and springs after cam break in? My 260,000 mile 4.0 idled for hours at a time on a regular basis and I always beat the tar out of it like over 5k rpm for minuets at a time and when it decided to give up it was mostly cylinder wall and piston ring wear and the push rods and rockers were whooped but the cam and lifters looked to be in normal shape for 260,000

Id do the long rod and good pistons if it was me.Yes the forged are a little noisey for a few minutes but not a big deal.I live with temps like yours and no problems idling for 20 minutes in the winter when it 10 degress outside or sub zero this past winter.You cant drive it if you cant see.lol You do have to use the right oil.I use brad penn but anything designed for flat tappets will work.Whatever you pick for a cam have it double nitrided!Its cheap insurance.

Here's something that confuses me.

Dino's 4.6 Mod Poor Man recipe with the Keith Black forged 944 (4038) pistons recommends 0.020 overbore, and he comfirmed that in an email.

He also told me that factory cast pistons in a stock 4L have up to 0.060 overbore, depending on model year.

So Dino was (in effect) saying stock pistons have more overbore than KB forged pistons.

Wouldn't that mean stock pistons would rattle more at cold start than KB forged pistons?

Please ignore my prior post. I had misunderstood what Dino told me.

charley3 wrote:Here's something that confuses me.

Dino's 4.6 Mod Poor Man recipe with the Keith Black forged 944 (4038) pistons recommends 0.020 overbore, and he comfirmed that in an email.

He also told me that factory cast pistons in a stock 4L have up to 0.060 overbore, depending on model year.

So Dino was (in effect) saying stock pistons have more overbore than KB forged pistons.

Wouldn't that mean stock pistons would rattle more at cold start than KB forged pistons?

You're getting the size of the cylinder overbore confused with the piston-to-bore clearance (PTBC).

Recommended PTBC for IC944 forged pistons is 0.0035"
PTBC for stock cast pistons is 0.0015-0.0020"

A higher PTBC increases the likelihood of cold start piston slap.

wjtom wrote:Whatever you pick for a cam have it double nitrided!Its cheap insurance.

Nitriding isn't the savior you are making it out to be.

SilverXJ wrote:

wjtom wrote:Whatever you pick for a cam have it double nitrided!Its cheap insurance.

Nitriding isn't the savior you are making it out to be.

It might protect the cam lobes but the lifters can still go poo poo.