Jeep XJ Stroker build

[gummij]

I’m new to this forum. I’m thinking of building a Stroker (NA non turbo)for my 2001 XJ . I will need exceptionally reliable engine, capable of withstanding full throttle at 5k rpm on long cruises on Icelandic glaciers as the old 4 L engine can do. I’m not going to do this unless I can expect more than 270 hp at the flywheel and at least 70 k miles from the stroker. If not I will go for an 5.3 GM (L66).
The XJ is currently equipped with the original engine and has 150 k miles on it. I also have an engine from an 2000 XJ which is supposed to have about 60 k miles available for the build. I’m ready spend up to $2000 on parts. I will run on something like 89 octan fuel ((R+M)/2)
So the big question is, is It possible ? If Yes, Then what kind of setup is likely to be the winner

The rig is used in trips like this.
https://www.youtube.com/watch?v=I6uPXbifVEA
https://www.youtube.com/watch?v=I6uPXbifVEA

[SkauneJohan]

about 240-250hp is very possible with a 4.6 stroker, 4.7 stroker will give you about 260-270hp

if you want more than that there are a few ways to go: either go with supercharging (turbo, blower or centrifugal compressor) or boring the block even more or lastly going for a wilder camshaft

another good site about stroker is: http://www.jeep4.0performance.4mg.com/stroker.html

is there a reason why you want to run 5000rpm all day? the stroker will like lower RPM than the regular 4.0.... that is sortof the reason for stroking, getting more power at lower rpm and avoid the need to go full throttle/high rpm always, a stroker in theory atleast will wear a lot more in higher rpm than a regular 4.0


in my opinion if you want an engine to run at 5000rpm all day just rebuild it and blueprint/balance the 4.0 and put a centrifugal supercharger on it

hope this help

cheers/Johan

[gummij]

Thanks for the answer Johan.
“”is there a reason why you want to run 5000rpm all day?””
Not all day. Being able to keep it at max throttle and hi rev for period half an hour is crucial, maybe 3 times a day 20 day of the year. To get speed in snow you need hp. If you shift up and the rews go down you get less hp and the car slows down until you shift back down and you will end up running at 4000-6000.
Maybe the goal is to get max hp at 3500-6000. The stock 4l l is actually good at this but needs mor total HP.
Building a hi rew 4l engine with big cam and valves would get the HP I need. but will require lower, (weaker) gears and i think it might be hard to get the cam and valves to last in it.
Any kind of turbo is not a option.

[SkauneJohan]

stroker engines usually give a LOT of extra power in low-middle range (depending a lot on camshaft selection)
so if that is where you want the power, a stroker is definatley for you

there are strokers made to rev insanely high rpm but those are more extreme builds and put out a lot more horsepower. The cost for engine built in such manner is also a lot higher

higher rpm will always be more expensive to build

if you google GOLEN engines you get a good built engine that is ready to put into your car

[gummij]

thank you for that Golen link Johan. I will build the engine in Iceland and innport the parts for it.
I guess I am looking for setup close to this.
https://www.golenengineservice.com/docu ... p%20LB.pdf
https://www.golenengineservice.com/docu ... -270hp.jpg

But there is no info on the cam, just that it is a CompCam. does anybody know the cam numbers in that setup. ?

How abut using stock cam and head from the 2000 engine with porting and multi angle valve job on 4,6 liter stroker. What kind of CR can by used an how many hp can by expected from that. ?

[I6FAN]

But there is no info on the cam, just that it is a CompCam. does anybody know the cam numbers in that setup. ?

I think they were using the 68-235-4 Xtreme 4x4. Their old site actually quoted that cam, and the dyno graph looks the same.

[akadeutsch]

I thought the rule was...to build for high rpm power you should de-stroke an engine and for low rpm power you stoke an engine. have you considered de-stroking and boring the shit out of it?

Keith

[SilverXJ]

How abut using stock cam and head from the 2000 engine with porting and multi angle valve job on 4,6 liter stroker. What kind of CR can by used an how many hp can by expected from that. ?

The cam you could use depending on wear, but it might give you a high CR. As for the head I wouldn't use a 99-2002 0331 head as they are prone to cracking. 2003+ "TUPY" heads have fixed the cracking issue.

[HuggyBear]

For what he wants to do, I would recommend a small block chevy/ford.

I'm in the process of building a 4.6, but if I had known the expense of building this engine, I would have just built a 350 and be done with it.

[gummij]

How abut using stock cam and head from the 2000 engine with porting and multi angle valve job on 4,6 liter stroker. What kind of CR can by used an how many hp can by expected from that. ?

The cam you could use depending on wear, but it might give you a high CR. As for the head I wouldn't use a 99-2002 0331 head as they are prone to cracking. 2003+ "TUPY" heads have fixed the cracking issue.

I m not following you on the CR ? . Using small, (short duration) cam will result in DCR (Dynamic Compression Ratio) close to CR or SCR (Static Compression Ratio). In general, Big cams can use higher CR than smaller cams. Cam selection will not effect the CR. Selecting a small cam will require low CR. Question is what level of CR can be used in that setup.

I have both types of heads available for the build 0331 TUPY and an 0331 non TUPY.

[gummij]

I found out the engine in the 2001 jeep has an head marked with the letters TUPY under the oil filling cap, which is supposed to be less prone to cracking. The other head (from 2000xj) is non TUPY 0331 casting, but not cracked and only has 60k on it and in excellent condition. After reading the internet on the non TUPY 0331 head is looks to my its not so much of a problem, unless the engine is over heated and I don't think I will be doing that, at least not willingly.

I think my plan now is to build the 2000 engine as a 4.6 liter stroker using the stock longer rods and new 3.895 crank and start on the non TUPY 0331 head (lightly ported). When its running I will pull the 0331 TUPY of the 2001 engine for ultra portig. Cam, pistons and CR selection is still a ?

[SilverXJ]

I m not following you on the CR ? . Using small, (short duration) cam will result in DCR (Dynamic Compression Ratio) close to CR or SCR (Static Compression Ratio).

I wouldn't say close to SCR. I would say closer.

In general, Big cams can use higher CR than smaller cams.

cams don't really 'use' SCR, more like work with certain SCR numbers.

Cam selection will not effect the CR.

Yes cams will effect the DCR.

I found out the engine in the 2001 jeep has an head marked with the letters TUPY under the oil filling cap

must have cracked at some time and been replaced.

After reading the internet on the non TUPY 0331 head is looks to my its not so much of a problem,

What you read is incorrect. The engine doesn't have to overheat to crack the head. They just crack. You can do perfect maintenance and it will still have the possibility to crack. If you want to put garbage on your engine do for it... it is yours. Investing money into a crack prone head is a waste.

[gummij]

[quote="SilverXJ" The engine doesn't have to overheat to crack the head. They just crack. You can do perfect maintenance and it will still have the possibility to crack. If you want to put garbage on your engine do for it... it is yours. Investing money into a crack prone head is a waste.[/quote]

Read/think before posting. I did not say it needs to overheat. I said it was not so much of a problem unless it overheats. Maybe I should also point out that i don't need basic lessons in IC engine mechanics. So lets keep this thread on the jeep stroker specific base.

[SilverXJ]

Read/think before posting. I did not say it needs to overheat. I said it was not so much of a problem unless it overheats.

I'm pretty sure you are the one who needs a reading lesson. The head is a problem irregardless if it overheats or not.

Maybe I should also point out that i don't need basic lessons in IC engine mechanics.

It appears you may.

[jsawduste]

Read/think before posting. I did not say it needs to overheat. I said it was not so much of a problem unless it overheats.

I'm pretty sure you are the one who needs a reading lesson. The head is a problem irregardless if it overheats or not.

Maybe I should also point out that i don't need basic lessons in IC engine mechanics.

It appears you may.

Read more and comprehend what is being offered rather then going on the defensive. The non TUPY has earned a reputation for a reason.