2.5 engine question/options.

[Marty, SoCal]

The 2.5l and 4.0l share the piston and rod assy., as I'm sure you know. Both stock pistons and rods are cast. Better parts would allow for more RPM/Power, especially with boost. The 2.5l has a shorter stroke, though.

I just read your buildup of the turbo YJ, very cool!

I'm interested in seeing how you get extra stroke in the 2.5l, I'm guessing an offset grind with a 2" diameter (early chevy) rod journal? A billet or forged crank would be nicer, though!

A OBD-1 MPI 2.5l would make a nice swap into an old flatfender Jeep. Keeps it all "Jeep" that way!

[Dave07]

if the price is right i buy a rebuild kit for my 2.5. im not looking for anything crazy. but i need more power.

[jpfrk2001]

Originally Posted by Marty, SoCal

The 2.5l and 4.0l share the piston and rod assy., as I'm sure you know. Both stock pistons and rods are cast. Better parts would allow for more RPM/Power, especially with boost. The 2.5l has a shorter stroke, though.

I just read your buildup of the turbo YJ, very cool!

I'm interested in seeing how you get extra stroke in the 2.5l, I'm guessing an offset grind with a 2" diameter (early chevy) rod journal? A billet or forged crank would be nicer, though!

A OBD-1 MPI 2.5l would make a nice swap into an old flatfender Jeep. Keeps it all "Jeep" that way!

THanks for reading my thread. This 2.5 crazyness is due to my current buggy build thread(in my sig). The engine idea was started over a year ago. We are just finally at the time to pull the trigger and start working with metal. I just want to be different.

Originally Posted by Dave07

if the price is right i buy a rebuild kit for my 2.5. im not looking for anything crazy. but i need more power.

I would like to put a base "kit" together for under $1000 if I can. Lets just see.

[jpfrk2001]

BTT for another round of voting.

[Mesquite Smoked]

How is the 4 banger going. Im really really into this idea. As soon as you can release info I want it, or the shop to send my engine to so it can get the magic treatment done. The idea of a 4 banger in a hot rod jeep is freakin cool stuff.

[jpfrk2001]

Originally Posted by Mesquite Smoked

How is the 4 banger going. Im really really into this idea. As soon as you can release info I want it, or the shop to send my engine to so it can get the magic treatment done. The idea of a 4 banger in a hot rod jeep is freakin cool stuff.

The company is waiting on me to give them the down payment. So it will be a little while till this gets started. Once it get started, it may take another year till the first engine would be ready for testing.

[Sillyfast]

Originally Posted by jpfrk2001

The company is waiting on me to give them the down payment. So it will be a little while till this gets started. Once it get started, it may take another year till the first engine would be ready for testing.

get on this, I rock a 2.5 for now, keeps things simple to work on but when I am done with suspension and body mods I will be looking for more power.

[redlig23]

Originally Posted by Sillyfast

get on this, I rock a 2.5 for now, keeps things simple to work on but when I am done with suspension and body mods I will be looking for more power.

i heard that i have a 2.5 too and would love to see what i can do with the 4 id do a swap but would love to be different and rock the 4 banger

totally messed that up haha stupid spell check i meant i have a 2.5 not sure where the i heard came from

[jpfrk2001]

To the top for the newbs.

Also: Plan on plopping the down payment next month!!

[PacificNWestJeeper]

There is no replacement for displacement.
Pull it and put in 8 ponies.

[jpfrk2001]

Originally Posted by PacificNWestJeeper

There is no replacement for displacement.
Pull it and put in 8 ponies.

Well, not with my project. Im going with the 4 banger. But you have a good reason why. Its more what you want.

[LetchcoreCJ]

I know in the offroad world most people dont care about MPG but people that weekend wheel and drive their rigs during the week do. I am currently building a Scrambler that has no engine yet. I was tossing around the idea of a 2.5L or 4.0L stroked or with boost for power and MPG. I have 4.6L stroker with a NSG370 6 speed in my CJ7 that makes great power, is reliable and gets 22mpg on the highway. I would be interested in the power a 2.5L would make stroked and its highway MPG's. Sure a V8 swap gets you lots of power but I have never got over 16 MPG in a CJ. To make great power with a 4cyl or 6cyl and have an efficient engine on gas is the name of the game these days I think. Just look at the ECOBOOST engine in the new F150's. No one thought truck buyers would get anything but a V8. Turns out Ford is selling more ECOBOOST engines than any other engine in the F150. Ford is now releasing 4cyl ECOBOOST engines in other cars because they are more efficient and make plenty of power.

I like your idea and think it would sell.

[jpfrk2001]

Originally Posted by LetchcoreCJ

I like your idea and think it would sell.

Thanks Man!!

[Irongrave]

you looking for investors in this motor idea. I'd be willing to throw something into a paypal for ya to get it going.

[jpfrk2001]

Originally Posted by Irongrave

you looking for investors in this motor idea. I'd be willing to throw something into a paypal for ya to get it going.

Not now. I don't want to take money from people and have this thing fail. It won't fail, just would rather do this alone right now. I do have some of the best engine builders/enginners on the project. Its just the crank investment that is really the big ticket item.

But I will keep you in mind.

[YellowRenegade]

definitely an interesting idea. I've never had a 4 cylinder jeep, but i can appreciate the idea of keeping the smaller motor because of gas prices.

good luck!

I have held on to my I6 a lot longer than i meant to because of mpg's.

[jpfrk2001]

Originally Posted by YellowRenegade

definitely an interesting idea. I've never had a 4 cylinder jeep, but i can appreciate the idea of keeping the smaller motor because of gas prices.

good luck!

I have held on to my I6 a lot longer than i meant to because of mpg's.

Thanks. I need all the support I can get on this.

[xrayjeeper]

I already plan on getting a 4 banger for my next jeep. Would be nice to be able to hop it up some with out the hassle of a motor swap.

I plan on the 2.5 for the gas mileage aspect as it would be a DD also, how bad would the basic stroker kit hurt gas mileage?

[jpfrk2001]

Originally Posted by xrayjeeper

I already plan on getting a 4 banger for my next jeep. Would be nice to be able to hop it up some with out the hassle of a motor swap.

I plan on the 2.5 for the gas mileage aspect as it would be a DD also, how bad would the basic stroker kit hurt gas mileage?

Well. . it depends on what you want for mileage? inline 6 stock offroad, you might get 9 mpg/14 around town. This motor, I don't know?! Im not planning for mpg for this motor. My 4 cylinder offroad, might get 8 mpg. The basic stroker could be the same as a stock 4.0

It takes more fuel to make more power. Nothing can be done about that. Laws of physics.

[xrayjeeper]

Ya I knew it would take a hit just wondering how bad it would get hit

[yager]

I voted bacon.... I had looked into the 2.5L motor, any current available parts were very expensive and the end result was still very little improvement over stock... I'm not bashing the motor I actually thinks its a good torqy motor.. I opted to swap in an exotec, 250# all alum. DOHC, with tons of aftermarket support etc.. stock 2.2 eco = 2.5 jeep motor, plus I can rev up to 6k stock. Factory turbo and charger options also..

I paid $400 for a motor w/ 48k granted I'm still working on the swap but the end is in sight...

To me the simplicity in the 2.5 is negated when you try to build it up. If you need more do a 4.0L swap, dono XJs are so cheap now..

my .02

[zachv]

Just saw this thread. I am interested, both as a 2.5 owner and as a business person. Do you have any numbers yet, even ball-park, for what a typical customer will spend? What do you expect your time to market will be at this point?

[jpfrk2001]

Originally Posted by yager

I voted bacon.... I had looked into the 2.5L motor, any current available parts were very expensive and the end result was still very little improvement over stock... I'm not bashing the motor I actually thinks its a good torqy motor.. I opted to swap in an exotec, 250# all alum. DOHC, with tons of aftermarket support etc.. stock 2.2 eco = 2.5 jeep motor, plus I can rev up to 6k stock. Factory turbo and charger options also..

I paid $400 for a motor w/ 48k granted I'm still working on the swap but the end is in sight...

To me the simplicity in the 2.5 is negated when you try to build it up. If you need more do a 4.0L swap, dono XJs are so cheap now..

my .02

And I would expect nothing else from you. Yea, I did explore the ecotec route. But I want to be different

Originally Posted by zachv

Just saw this thread. I am interested, both as a 2.5 owner and as a business person. Do you have any numbers yet, even ball-park, for what a typical customer will spend? What do you expect your time to market will be at this point?

All numbers have been crunched through a bench dyno. But nothing real as of yet. Everything is still on paper. I am hoping a "kit" would come in at less then $2000.00 for a the basic kit? I don't know? It really depends on cost to mill out more units after the test unit is finalized. And Im the tester! I might seriously put the engine in my jeep and start DD'ng the jeep.

Time: Well, as soon as I drop the down payment, the first crank could be ready from 6 months to a year. I believe the connecting rods and pistons are off the shelf, but for a completely different popular motor application. So hoping to save money using Hi-Po internal parts from different application thats readily available and not to expensive.( Cant let the entire cat out of the bag)

But mine is being built for a full out turbo race application. So Me and my enginner are not pulling any punches on this. Custom ground cam for a turbo, fully studded lower and upper using ARP, as also alot of go fast tricks, that also add in reliability.

THIS WILL HAPPEN PEOPLE, IT MIGHT JUST TAKE ME 2 YEARS FOR FINAL PRODUCT. BE PATIENT!!

It has taken Jrat close to 3 years on his 69 idea. And I think He is almost done.

Gotta be carefull, starting to sound like a vender. Please don't turn me in.

[EricsGreen98Tj]

I've had two 2.5L Wranglers. A 95Yj and my 98Tj. I LOVE my 2.5's. The only bad thing about them is the crappy AX5. I put 3 trannys into my Yj and I already have an NP435 waiting to go into my Tj once I buy the adapters. I've looked around a bit for "power aids" and havent really liked anything that I've seen. I'd really like to be able to squeeze a few more pony's out of the squirels for highway driving though. Thats really the only bad thing about a 2.5; The Highway....

Work some kit out that gives decent power increase and I'll be happy to be on the "Add to Cart" list.

Keep us posted on whats happening with this.

[steve97tj]

Anyone who's saying theyre opting for the 2.5l for the fuel economy has a rude awakening, it gets almost if not as bad as the 4.0, i DD'd one for 5 years and will be driving it again semi-dd after the swap. I didn't buy it for the mileage though. I have a rebuilt ax5 with less then 5k miles on it but i agree its crap, I'd love to get an ax15 to eventually throw in it if i get any trouble out of this one.

If you need another tester i'm in SC, right beside the GA line (im thinking you live in GA somewhere) and would be happy to get in whatever your trying to do.