Bratcop's Stroker Build

[bratcop]

With the pretty pan on, this is what it looks like...I went with a ceramic gunmetal grey paint for the block, same paint in semigloss black for the head, and of course, the sparkly silver for the pan...

Jeep Laredo-19.jpg

I installed the intake and exhaust manifolds on the head, and put the injectors, fuel rail, and bored out TB on the intake and prepped it for assembly...ain't it pretty? Chose a textured charcoal Gray metalflake for the valve cover...just a light sanding and a shot...I hope it holds up to the temps...click the pic for a better look...

Jeep Laredo-02_edited.jpg

I then took some shots of the block in...it seems so spacious in there....which makes the stroker soooo much cooler...all that power from such a little plant (listen to me, it isn't even running yet)

Jeep Laredo-03.jpg

I don't have any pics with the intake on, but I will get some next weekend...

We completed putting the head on, valve train, valve cover, coil pack, wire channel, connected all the sensors and other electrical that was disconnected for the enginectomy...

Obviously bolted it back to the tranny, installed the trans mounting hardware (those goofy pipes across the bottom of the bell housing up to the block) and put the starter back in. Man those new starters are tiny, but I imagine high buck...much lighter than the last starter I installed (1968 CJ5 with the Dauntless V6).

After I headed for home, my Dad (who has been a great help and an inspiration and is the gent in the background of one of the pics), installed the radiator and fans...

This weekend I should be very close to firing it up. I was still looking at CAI, namely the K&N FIPK, but I am a bit skeptical..on a stock motor it gives like 6hp, but at a ridiculous rpm, like 4780 or something...that seems a bit useless, and if I recall correctly even lower torque numbers...anyone got a better idea? I would like something with a heat shield or maybe more of a tube to the area under the headlight? Does Voltant make a good product? Input greatly appreciated...

[gradon]

Yeah, I had to go with two washers as well and what a pita it was to clearance for that and the hi-vol pump--my pan is not pretty. I still wonder if I should've nabbed the pan at the JY when I bought the $5.66 girdle--it would've saved 45min of banging.
edit: I recommend(to those planning builds) finding a girdle from a 96+ 4.0 and using it on a stroker build--it'll help stiffen up the bottom end/reinforce the crank. So as you can infer from the above, maybe grab the oil pan and of course the studs w/ nuts(that hold the girdle and main caps) and you'll have to buy washers to get the girdle to clearance the crank and then deal with getting the oil pan on w/o the girdle getting in the way. Fun, fun, fun.

[SilverXJ]

I had the same problem with my oil pan. It wouldn't fit with the spaced out main girdle. Had to beat the piss out of it to make it fit. Its ulgy.

[Mgardiner1]

I actually opted to NOT find a girdle. I'm not so sure if the benefit outweighs the negative for my application. If i was boosting or turning high RPMs i'd go with it, but i feel it reduces the windage that the crank might get from the oil in the oil pan, which would further reduce oil lubrication to parts that rely more on splash lubrication (IE cam lobes).

[Mgardiner1]

Bratcop, any updates? It seems from your post in another thread that you've got it up and running. No other parts to your story? Details? etc?

[bratcop]

So my Laredo Stroker is alive....and the parts work quite well

Here are the final stats and details

completed the block installation and bolted on the head and VT. At the advice of my machinist and my Father I did not modify the VT geometry. They both felt that the wear on the engine at 95k would make up for the change made by decking the block and flattening the head...who am I to argue? Between them they have 60 years engine building experience...
Anyway...installed everything, then checked everything again...
plugged in all the electrical. We had some other stuff to do while we were building, like replace the tie rod (which had rusted through due to water infiltration)...

Went with Delo 15w40 oil for break in with a bottle of Comp Cam additive. Topped off the radiator with antifreeze and checked for leaks...none to be seen...

charged the battery, cleaned the cables and connected it...

turned the key and the rest is what movies are made of....literally....watch it here on youtube
http://www.youtube.com/watch?v=WrPv_ory1Io


Needless to say here is how it went...

started after only a few cranks to just get the oil pressure up...
It fired up and did pretty well with out computer modification
I chose not to install the PSC1-003 because I wanted to rule it out as a possible cause of any problems...I will consider installing it once all the other bugs are worked out...lucky me, there are very few bugs....

I chose to stay with the original intake. I am assuming that it is adequate volume for the 4.5L. Besides I came to the realization that everything I was looking for in a CAI (for example getting a good gulp of outside air, insulation from engine compartment heat, K&N filter...) are addressed by using the original. It had a K&N filter in it when I bought it, it is designed to grab air from in front of the radiator, and is a complete plastic box insulating from engine compartment heat. I used a dremel to take a big chunk out of the plastic tube that extends into the factory air box below the filter...just to increase the potential air volume....The corrugated tube between the filter and throttle body is very short, like about 5-6 inches, so I figure it can't disrupt the air too much due to it's corrugations.

I stayed with the factory exhaust because it is 2.5" pipe to the muffler, then 2.25". The muffler is still in great shape, so I couldn't ditch it yet, but when the time comes...

So it started and idles smooth. I got a CEL quickly, so we drove it to Autismzone and had them put their scan tool on it to find it was a sync fault indicating that the cam position sensor and crank position sensor are a little out of sync. They can only be out 2 degrees either way. 95% of the time it idles fine, but on occasion (like every 120 miles) it starts to miss and stumble. Just shut it off and let it sit like 2 minutes and restart, and all is fine. I reset the light and it cam back instantly.

I drove the Jeep 100 miles home, varying the speed via the OD switch. Since I reused the cam and lifters, I don't need to break them in like they were new. I just ran it that way to seat the rings.

I ran it through a tank of old 87 octane without a single knock. I am running about 9.6:1 SCR and 7.9:1 DCR with about a .044 quench. I got about 16 mpg on the first tank of gas and will keep you posted on improvements...

The bug...the fuel synchronization (cam and crank sensors) We tried our hardest to synch them, but are obviously off slightly. It runs very smooth and quiet 95% of the time, but that 5% and the CEL let me know we were off a little. I have researched the fix and it seems I need to take it to a dealer to have them do a fuel synch with a special tool (DRB I think). I was hoping I could do it with an obdII software interface, but the think the stealership is the only way to go...anyone got any ideas? I can't just tweak it a little this way or that, as it already idles beautifully almost all the time...

I was surprised how well it does on closed loop. I thought the mixture would be farther off, but there is very little hesitation when you mash it, and no knock...

I am thinking I might ebay the PSC that I have, not sure yet...

Performance....hard to say as I didn't drive it with the stock 4.0, but those of you who have driven on with a stock 4.0 chime in...a roll on start at 5-7mph will cause the 17 wheels to spin and smoke (3.73 gears). A mashed throttle will cause the tires to break free on dry pavement and spin easily through an entire intersection...the throttle response is instant and I love it.

Something I was suprised that I like is it's quietness. Many times I have walked outside when I left it idling thinking it had died, but it is quietly purring away, unbelievable. You would never know it wasn't stock...until you drive it. I love the sleeper effect. I imagine the Instant Fuel Economy and average Fuel Economy on the overhead computer are inaccurate because of the bigger injectors, but still fun to watch.

about 300 miles and the oil is still clean, will spin the filter off soon and drop the oil to 5w30 to improve mileage and engine response...again without a cam and lifters to break in, oil change is not as important to do immediately.

You can certainly tell that it has higher compression at start-up, the starter works a little harder than others I hear...

On the drive home, the temp dropped to 100 on the gauge and the heater started blowing cold air...I was worried, figured air bubble. Stopped to top it off, and it was full. Got home, pulled the thermo (which was initially a high flow Mr. Gasket 180*) and found it stuck in the open positon. Replaced it with a lifetime guarantee Stant (180*) and all is fine. Cooler thermo will hopefully ward off the pings in the summer months...

BTW, I am running at about 500 feet above sea level on the coast of Lake Michigan, so those who say strokers will be problematic at sealevel, I HAVE NOT SEEN THAT YET. Even with my higher compression. I assume that may have some to do with winter air and great quench....but still...

I will post some more pics of the finished engine bay in a couple days.

Thanks to all who helped with this build...Oletshot for the piston work, Tall Peter for the Rods, and all the big brains for the answers...

BRATCOP

[SilverXJ]

The bug...the fuel synchronization (cam and crank sensors) We tried our hardest to synch them, but are obviously off slightly. It runs very smooth and quiet 95% of the time, but that 5% and the CEL let me know we were off a little. I have researched the fix and it seems I need to take it to a dealer to have them do a fuel synch with a special tool (DRB I think). I was hoping I could do it with an obdII software interface, but the think the stealership is the only way to go...anyone got any ideas? I can't just tweak it a little this way or that, as it already idles beautifully almost all the time...

Bring piston #1 up to TDC on compression stroke. Insert some sort of locking pin through hole on bottom of sensor body and hole in window wheel, locking the wheel in place. put sensor in place with socket pointing toward the rear. You may have to move the oil pump to get it to line up with the cam and pump. Once in, bolt down and remove pin. That should do it. The dealer can fine tune it VIA the DRB, but I don't know it that is necessary. One option would be a stretched timing chain.

[bratcop]

Silver, that is how we set it up upon reinstall. used a wd-40 spray wand to lock it. i know it isn't a timing chain as mine is new... it also points directly back...it has to be very close, but it could be off 2 to 3* quite easily...ya know? is dealership the only people that have that type of tool typically?

[SilverXJ]

The WD40 stick is what I usually use as well. Yes, the dealers are usually the only people that have the DRB tool. IIRC you can find them on ebay for around $1300 some time.. lol. I've done it at least 5 times and never god any kind of error. Perhaps the sensor is bad on it? Especially since you say it takes quite a while for it to happen.

[bratcop]

Silver, I found this article online and it hits this on the head exactly...give it a read. I will probably be buying some toothpicks soon.

http://motorage.search-autoparts.com/mo ... rticle.pdf

Bratcop

[SilverXJ]

Ahhh.. that article. I read that a few years back when I swapped a cam into a 4.0. Its a very good read and it helped me a bunch.

[RAPTORFAN85]

Great build bratcop. It's good to see that the motor is running relatively problem free (other then the sync problem)
I was watching your project closely because I am building my engine with almost the same specs as you and since we are only 200ft difference in elevation, its good to know that elevation won't be a huge factor.
So you think that the stock computer is capable of handling the stroker? that was another of my questions. If thats the case then that would be great.

[SilverXJ]

Yes, the computer will be fine with the stroker. I had one in my 00 XJ and building another one for it.

[gradon]

I need a toothpick too--probably why I get a random misfire cel on my replacement ecu and why I got the intermittent loss of cam/crank signal cel a couple times on the original. Excellent pdf!

[Bodo]

So was the dog helping?

My serious question is: What is that aweful grinding/whine when the engine is turning over or running?