I want a stroker but not sure about a few things

[FlexdXJ]

Ok, I think I am going to be building a stroker here in the next few months. I am going to start with the motor out of my wrecked 97. So I have an 0630 head Correct? What am I looking at to run regular gas in it? I have no problem running premium but would rather run it on regular unleaded since it will be in my DD(that will get wheeled as well). This is just the beginning of the research phase, Which will hopefully last through my Time off(layoff ) from work.

 

[turbojeeper]

try here for all the stroker possibilities. www.jeep4.0performance.4mg.com/stroker.html

and here for all other stroker things www.jeepstrokers.com

 

[FlexdXJ]

try here for all the stroker possibilities. www.jeep4.0performance.4mg.com/stroker.html

and here for all other stroker things www.jeepstrokers.com

Thanks, I've been to both already though. I started there!

 

[turbojeeper]

lol nice, i have been look at doing a stroker. i was planning on the 4.2 crank and rods and then some dished stoke bore pistons to keep the compression ratio round 9.0:1 or so

 

[FlexdXJ]

lol nice, i have been look at doing a stroker. i was planning on the 4.2 crank and rods and then some dished stoke bore pistons to keep the compression ratio round 9.0:1 or so

I was looking at around 9.7:1 but I really want the option to run regular gas since its gonna be a NA motor. 9.0:1 is around where you want it for a turbo motor, correct?

 

[turbojeeper]

lol, you hit that nail on the head.

 

[wolfpackjeeper]

I did not really pay that much attention to mine. Took enough off the head to get it perfectly level, and I think 12 thousandths off the block. Everything else fit fine and cycled without interference, so I said xxxx-it and ran with it. I can run regular gas except on the hottest days.

 

[Goatman]

To be able to run regular gas you need a balance between compression ratio and quench height, so look for information on that. Less quench means a smaller combustion chamber, so you need more dish in the piston to keep the compression from being too high. The less quench height you have, the higher compression ratio you can have and still run regular (within normal specs). I believe ideal quench height is in the .040-.045 range, but I don't know what experience people have had with compression ratio and regular gas. Both of my strokers used premium because of higher compression.

 

[FlexdXJ]

To be able to run regular gas you need a balance between compression ratio and quench height, so look for information on that. Less quench means a smaller combustion chamber, so you need more dish in the piston to keep the compression from being too high. The less quench height you have, the higher compression ratio you can have and still run regular (within normal specs). I believe ideal quench height is in the .040-.045 range, but I don't know what experience people have had with compression ratio and regular gas. Both of my strokers used premium because of higher compression.

Thanks for the info goatman, Like I said this is just the beginning of the research phase. I will be spending some time on Jeepstrokers.com during my layoff. The 4.5 i was looking at was somewhere around 9.7:1 and the quench height was like .081 using a stock head gasket.

 

[gradon]

Zero deck height, victor reinz .043/.044 head gasket, and use pistons w/ a mid-high 20s cc dish(oleshot on strokers can dish them for you), should let you use regular(unless you use a very small overlap cam). Last week I yanked a good 4-weighter from a 87-90 wrangler for $30 at the JY to trade for a 12-weighter(that will be offset ground)for my brother's 5.0 turbo build(ahem 4.9). His static compression will be around 8.75:1.

 

[FlexdXJ]

Zero deck height, victor reinz .043/.044 head gasket, and use pistons w/ a mid-high 20s cc dish(oleshot on strokers can dish them for you), should let you use regular(unless you use a very small overlap cam). Last week I yanked a good 4-weighter from a 87-90 wrangler for $30 at the JY to trade for a 12-weighter(that will be offset ground)for my brother's 5.0 turbo build(ahem 4.9). His static compression will be around 8.75:1.

Damn. the venerable 5.0-ish stroker! Is his going to be anything like the JP one with retarded HP? Should i look for a 12wt or 4wt crank since this isn't going to be a super high performance build, Just a reliable DD motor.

 

[AIbandit]

Damn. the venerable 5.0-ish stroker! Is his going to be anything like the JP one with retarded HP? Should i look for a 12wt or 4wt crank since this isn't going to be a super high performance build, Just a reliable DD motor.

Everyone Ive talked to recommend the 12wt. unless you're going for street power then 4wt since 12 would take more to rev.

 

[FlexdXJ]

Everyone Ive talked to recommend the 12wt. unless you're going for street power then 4wt since 12 would take more to rev.

Cool, I'll lurk on JS for a while and see what year engines these are found in and go from there.

 

[xj-grin]

you want the 12wt crank. I agree with everything above, and Dino's site is the grail. Mines a 4.6 using an old accurate power kit (before they went belly up) - around 9.5-1, runs fine on regular pump gas with no pinging, but I'm also at altitude. Make sure you break it in with high-ZDDP oil, since flat tappet cams are sensitive to a lack of zinc at break-in, and strokers seem to be particularly prone to cam failures (IDK why, they shouldn't be). I am in the midst of a mild-rebuild on mine at 90k, since I apparently had a poorly cast head (even though it was a 0630) and had some compression loss/leakage into two combustion chambers (water jacket was actually cast to nearly overlap the piston/combustion chamber...). Fixed that and then could hear the clatter of low-end bearings. I am still sold on strokers for the bang for the buck factor and ease of installation & maintenance.

 

[dagr8tim]

Ok, I think I am going to be building a stroker here in the next few months. I am going to start with the motor out of my wrecked 97. So I have an 0630 head Correct? What am I looking at to run regular gas in it? I have no problem running premium but would rather run it on regular unleaded since it will be in my DD(that will get wheeled as well). This is just the beginning of the research phase, Which will hopefully last through my Time off(layoff ) from work.

I'm considering a very similar build with a 98 4.0 donor. My plan is a new OE oil pump, new bearings, rings, a 4 counterweight 258 crank, and run a hone through the cylinders to clean them up. Maybe some light head work to clean up any casting flash deck the head to get the CR back up, and possibly a slightly hotter cam. I know I could use a 12 counterweight crank, but that requires machining down the crank snout.

My goal is a slight performance bump, but something that can easily go 100,000 miles on 87.

 

[wolfpackjeeper]

(IDK why, they shouldn't be).

I am willing to bet that it is because they either do not use the ZDDP rich oils, or because everyone decks the block and heads then a lot of people forget that when setting up the valvetrain.

 

[Talyn]

No one will tell you what gas grade you can run or not. Too many variables and no set rule.

 

[FlexdXJ]

No one will tell you what gas grade you can run or not. Too many variables and no set rule.

Ok thats understandable, I just don't want to dump 2k into this build then have to run 91 octane all the time on my DD. I do have a 95 beater but I am going to build the DD to be able to drive across the country comfortably and still be able to wheel/explore where other vehicles can't go.

 

[Dr. Dyno]

The engine I have in my '92 XJ is the same as the 4.6L "Poor man's" stroker in my site except for the +0.020" 677P pistons that I used (9.25 CR), and I've been running it on 87 octane since the outside temp. dropped below 85*F.

 

[FlexdXJ]

The engine I have in my '92 XJ is the same as the 4.6L "Poor man's" stroker in my site except for the +0.020" 677P pistons that I used (9.25 CR), and I've been running it on 87 octane since the outside temp. dropped below 85*F.

Damn Just saw your Location. UAE? Its probably hotter than 85 most of the year there.