Stroking it!

[rick]

Sweet man! Glad you got it together and all is well. IIRC the compression ratio of the Accurate Power kit is like 9.4:1 or so? That alone will require at least midgrade to ensure no pinging under any circumstances. If it is ok under most circumstances but worse when you short shift it a bit and lug it then octane should solve the problem. Otherwise it could be lean? But I think the 24 lb/hr injectors should be plenty of fuel...

[nagal]

Thanks for the "teaching" cbremer Scarey enough I do understand what boring an engine is, the rest is just way above me now.

[cbremer]

Nice work chuck! Maybe try some 91 octane! what did your compression ratio come out to be?

best i can figure is somewhere around 9.4 or 9.5:1. a bit higher than i had hoped, but the machine shop did say that the deck wasn't exactly flat

[Dukes69]

woohoo! it's done... it runs... the distributor was one tooth off so it knocked and backfired a bit, especially under load. reindexed the dist. and all is well it's got a very slight ping in 4th gear so i might need to invest in octane booster (or 89 octane gas).

Nice work chuck! Maybe try some 91 octane! what did your compression ratio come out to be?

[cbremer]

woohoo! it's done... it runs... the distributor was one tooth off so it knocked and backfired a bit, especially under load. reindexed the dist. and all is well it's got a very slight ping in 4th gear so i might need to invest in octane booster (or 89 octane gas).

nagal, in the simplest terms, stroking an engine is a method of rebuilding using non-stock parts to increase the stroke (the distance the piston travels up & down the cylinder). in the case of the Jeep 4.0L, there are several ways to do this, depending on how much you want to spend i used a crankshaft from a 4.2L Jeep engine, 4.0L connecting rods, and custom-made pistons. I also bored the block over a bit, making the diameter of the cylinder a bit larger as well. my engine is now about 4.6L displacement. tons of fun

[nagal]

This thread has been totally fascinating for me even though I hardly understand it Any good books out there about engines that can help me to at least understand what everyone is talking about?

[cbremer]

well it fired up on the first try the directions that came with the cam said to run it for 20 minutes... which I did, of course. I haven't taken it for a spin yet since I still have a few minor things to do: bolt down the airbox, connect the ground strap, top off the transmission fluid (lost 4 or 5 quarts when I disco'ed the tranny cooler lines and removed the torque convertor). It starts after turning over 2 or 3 times and runs & revs like nobody's business. Oil pressure is right at 40 PSI cold. I can't wait to take it for a spin tomorrow Not bad for a first-time engine builder

[rick]

Looks nice, you need some help breaking in the cam? I'll hold the throttle open for you . That's the fun part...2,000 rpm for 30 minutes. The neighbors love that, especially if you do it at about midnight or so on a school night without the exhaust hooked up...

This is the pic I was looking for... Now I know for sure what these brackets are for on this junkyard engine I have - I thought they were XJ. I guess I need to keep scouring ebay for a wrangler a/c bracket. Damn I wish I paid more attention to what the heck I buy...

[Sully]

Boo now we cant race fair. Better hook up the nos........


Looks good Chucky.

[Kman]

She looks soooo SWEET!!!Wish I could be ther to hear her fire up for the first time!Actually I wish it was in my CJ!

[Dukes69]

what a mess!!

I mean . . . LOOKIN GOOD!!

[JeepGal]

WOW!

Thats purty Chuck!

Good luck with the install

Tam

[cbremer]

alrighty then... theis is getting serious

before:



making a little room to work:



OUT WITH YA!



seems to me that something's missing?



much better



finish up the wiring, new radiator & hoses, other odds & ends and (hopefully) firing it up tomorrow

[rick]

How about "Yeeee hawww"? Can I say yeee haw instead? I'll take it - heck, i'll even pull it myself.... we'll be in touch.

[D4x4Fish]

Looks fast anyways... I think that is the last 4.2L crank core in the US. Napa didn't have one when I first tried to order it (right after you did Chuck), and I have been through 3 places that say "yeah, sure we have one of those..." only to find out after they actually look on the shelf that they are out of them. I have started expanding my search...my father is looking for one in the engine scrap yards of good ole Detroit...

Rick I have 4.2 long block in the Garage. It'll cost a "Howdy" from ya. If you want the crank just say " Yea Ha".