Engine Upgrade Questions

[Allen78J20]

Im looking at putting in a new motor in the summer. I want to get a remanufactured short block, and the cam etc will more than likely be stock that comes with it. Has anyone just put on a aftermarket manifold and carb with good results on a stock cam? Was there any gain in power etc? Im not wheelin, its a daily driver, would like to be able to tow anything even though all I will do is tow the boat. Is there enough of a difference in a new stock short block with a aftermarket manifold and carb, upgraded ign, tfi upgrade versus a motor in stock configuration with stock coil and stock ign module with 160000 miles on it?
Any suggestions?

Thanks!

[badaboom]

Allen,
I would probably put in a cam other than the stock one myself. If you are going to go through the down time, all I can say the time to do what ever you want to do is then. I would say you will have a recognizable difference with the aftermarket carb and intake the ignition upgrade you noted also. I run the comp cam .268 hyd and related components and have been very happy with its performance. I would also get some other options. I also like engle cams also.
Yes you will most probably notice improvement over your 160,000 mile motor.
I also would probably NOT go crate motor but have the motor built how you would like it built. There are some pretty good oil mods on the tech pages that are suggested quite frequently on this website you might find of interest.
Best of luck on your project.

I like your home web page also pretty cool. :cool:
Just a note I have owned my J-10 since 1988.

[ January 07, 2004, 06:26 PM: Message edited by: badaboom ]

[Rogue]

i agree find a core engine and build it ground up, for jeep the summit cam is good choice (8600), cam is the heart of the engine and makes the most difference on how it runs more than any other part in the engine, it determines firing order, airflow, etc, etc, a good stock style rebuild with cam intake and carb will make a good engine, definetly get TFI or HEI upgrade and don't forget to open up your plug gap to 0.040 - 0.045 when you do, best money spent other than that would be some pocket porting

[Knucklehead]

Yes, build your own. I would step down on notch from the 268 to the 262 or even the 25? XE series. They have agressive lobe ramps and will
really wake up a motor. The AMC cam is woefully lacking. Advance the new cam 4 degrees and you will have a stumpuller.

I would not spend money to have someone else do and porting (I do my own so I always do it). The AMC head in the stock form is the AMC engines best point and exceeds most other old style stock heads out there.

Do the oil mod in the lifter galley. Search it out on froadin web site.

Other than that and TFI I would just keep it basically stock.

Put chevy rocker studs and rocker arms (roller if you got the money) on the heads. you can make this mod yourself with a drill and a GOOD tap once the heads are apart.

Oh yeh, have the machinest do a slight hone on the lifter bores. It will help make sure the lifter rotates in it's boar on startup and prevent a cam failure.

[Allen78J20]

I would like to build my own but I dont have the time(daily driver)or knowledge yet. I called the place I was looking at www.precisionengine.com (http://www.precisionengine.com) and they can put in a RV cam(didnt ask what brand, I will as I get closer to purchase)instead of the stock one.They also said they would put a Melling timing gear set instead of the dynagear set. From their website and talking to them on the phone they seem to be good people. Has anyone dealt with them before? Hopefully I can get to do this around the middle of April and take a vacation to get this done. I need to do the engine wiring harness while I am at it too. Can you hone the lifter bores with the block assembled? Also can you do the oil mod with everything installed? Doesnt make sense but I thought I would ask. Thanks for looking at my site badaboom! It needs to be updated badly.

Thanks again for all of the advice guys! Keep it coming!

[Knucklehead]

Ok,

Hunt around and find youself a builder block. you can get them cheap. Build it up in your spare time. It will cost you way less and you will probably do a better job. I have little or no faith in in these mass produced rebuilt engines.

I'm sure someone in your area can hook you up.

By the way I grew up southeast of Topeka.

[badaboom]

Allen,

Any block machine work should be done at the machine shop prior and during the machining and then assembly process. Meaning the
"hone the lifter bores with the block assembled"
NO
"oil mod with everything installed"
I would do it while apart at machine shop and have it put together during the assembly process.

If you don't want the down time I would find a good local rebuild and machine shop that wants to work for you to meet your needs in what you want in your motor.
Whats the hurry find a good block find a good shop come up with your requirements.
Have the motor built.

Make sure they have a warranty you will be happy with. Just remember they work for you.
So have them build it how you want it.

YOU HAVE THE POWER !!! LUKE

[ January 08, 2004, 08:18 PM: Message edited by: badaboom ]

[Rande]

If you go with the crate engine, take the time to check the cam gear for a blocked oil passage. There are two slots cut into the gear where the cam fits in. One is square for the key. The other is half round for an oil passage. Some gears come with a little obstruction right in the center, the slot doesn't go all the way from front to back. That bump in the slot has to be ground away for the oil to pass. It was a manufacturing defect and its likely some of these gears are still in the inventory.

[ January 08, 2004, 08:33 PM: Message edited by: Rande ]

[Knucklehead]

What Badaboom said.
Most machine shops will assemble a shortblock for about 100 -200$ if you don't want to do that your self. I do it because I'm anal.

Yes any work that generates metal filings/particles should be done before any assembly is done, followed by a thorough cleaning.

Take you time and plan it all out and do it right. You will like the results and knowledge that no corners have been cut.

[Millerluck]

Here is what I'm gona go with for a short block.

http://amracing.com/Jeep/engine.html

Scroll down to the 360/370 for $1800

Later

Larry Miller

[badaboom]

Millerluck,

Sounds pretty sweet.
This is new or used?
What is there warranty?

[jode]

I am actually running a stock cam. I had the MC 4350 carb on a stock intake and it was a dog. I then installed a Edelbrock performer intake and a carter AFB and she has NOTICEABLE power increase. I can now peel out (in fulltime 4WD mode) on my 31X10.50 BFG mud tires (3.73 gears I think) whereas before it required high speeds and tight corners to get a tire to break loose.

[carrotman]

Millerluck, that engine at amracing sounds sweet if you are going drag racing. 10.5 cr probably won't run well on pump gas. Plus, $1800 is a lot for a short block. You can get your engine built up for a lot less. I would keep the stock compression or 9:1 max. Then I would spend the extra money on the heads. You can unshroud the valves to increase low end power and efficiency, have the runners polished, and clean up the ports around the valve guide bosses.

[Knucklehead]

I agree, 1800$ is steep for just a shortblock. And where you live (about 900ft above sea level) 10.5:1 with a high torque cam would give you some serious detonation proplems. You can't go much over 9:1 unless you have a high overlap cam (bleeds off cylinder pressure), or live at a pretty high elevation or have aluminum heads.

And a big cam belongs in a vette not a truck. IMHO.

I would only modifiy the heads if I did it myself (and I did cause my time is free). AMC heads are better untouched that many heads are after they are massaged quite a bit. And they are the best cast "stock head" I've seen. ie not casting flash or sharp angle turns.

[79_Limited]

[QUOTE]Originally posted by Allen:
[QB]I would like to build my own but I dont have the time(daily driver)or knowledge yet. I called the place I was looking at www.precisionengine.com (http://www.precisionengine.com)

I heard positive things about Precision Engines on the Yahoo FSJ group.