Quick check on V6 characteristics

[CJ6]

I am going to piddle on the CJ6 this weekend.

What is the correct timing? I am thinking it may be a odd-fire? Not sure how to tell but it is a V-6 '67. Is the basic tuning the same if its an odd-fire? In other words do I turn the dist. to adjust timing etc? Is the points, dwell adjustment the same as my '72 360?

On the oil bath breather do i just replace with fresh motor oil?

Anything specific about this motor that will be really different from the '72 I am knowledgeable about?

Any plugs you guys suggest, gap etc.

Sorry, alot of questions. I don't have a good manual on it yet but I want to try to get the motor fine tuned and running perfect while I piddle this weekend.

Nelson

[Boyink]

If it's the original motor it's an oddfire.

Here's the tuneup specs from the factory manual...

Plugs are AC44s or Champion UJ12Y
Gap is .035
Dwell Angle 30 deg (Delco Dist)
Point Gap is .016
Timing 5 Deg BTC
Idle Speed 650/700 RPM


Straightforward tune-up - except for the rough-idle that's a Dauntless feature. Best advice I got was "tune it like it's two 3-cylinder motors". If you get a put put put ahhh put put put ahhh...that's what mine sounds like.

Yes turn dist to change timing. Dwell can be set while engine is running through little slideup window in the dist. cover.

Air filter is serviced by removing and cleaning up, summer oil is SAE 40 or 50, winter oil is SAE 20

(Just noticed that the manual covers both oil bath and dry type air filters - seems like we had that debate in the past).

Any other questions, I have the manual on my desk...

[69CJ]

If it's the original motor it's an oddfire.

Best advice I got was "tune it like it's two 3-cylinder motors". If you get a put put put ahhh put put put ahhh...that's what mine sounds like.



Hmmm... I may tinker w/mine today a bit to try and recreate this. My Dauntless idles pretty smooth and lacks any specific audible odd-fire character.

[Boyink]

If it's the original motor it's an oddfire.

Best advice I got was "tune it like it's two 3-cylinder motors". If you get a put put put ahhh put put put ahhh...that's what mine sounds like.



Hmmm... I may tinker w/mine today a bit to try and recreate this. My Dauntless idles pretty smooth and lacks any specific audible odd-fire character.

If it runs smooth you must have it all wrong! :) What's your idle speed? I notice the roughness more under 1000.

[Dave Cattani]

:D I rebuilt the 2 barrel on mine last winter and thought that I would never get it to Idle at cold temperatures ever again it would be smooth for 10 seconds or so and then die over and over until warmed up, I have no idea what I did but after about a month I did something right and now all seems good ( 17 miles/ gallon too!)
It is realy hard to achieve a SMOOth idle on an engine that doesn't know where 2 of it's cylinders are!!! HA.!!
Dave

[Hippo393]

On adjusting the timing by rotating the distributor: can you do that while the enigne is running? 2 weeks ago my 850 RPM idle was smooth, but today it's blah-blah-BPPTHLaA-blah-blAAH-blah. My manual says to disconnect the vacuum advance while adjusting, and plug it. How is it one can do that during the process? Do you just loosen the dist. bolt, disconnect the v.a.; move the dist. until engine's smooth; reconnect the v.a.; then tighten the bolt?
-alan :?:

[GDB]

I think it means to disconnect the hose from the advance and plug the hose so there is no vacuum leak during the tune up. Otherwise, the unit can advance a bit and make the setting incorrect.

[Boyink]

I think it means to disconnect the hose from the advance and plug the hose so there is no vacuum leak during the tune up. Otherwise, the unit can advance a bit and make the setting incorrect.

Yep - use a small bolt or golf tee.

And yes, change the timing while it's running.

So engine off, pull and plug the vaccum advance.
Hook up your timing light.
Loosen the dist. but don't turn it.
Clean up the timing marks on the motor, chalk the mark on the pulley if your light isn't that great.
Fire it up.
Set the timing by moving dist, checking RPM with tach.
Once set, turn it off.
Tighten Dist.
Re-attach vaccum advance.

[Mcruff]

Alan, one thing everybody should do especially to a newly rebuilt motor is to paint the the timing marks on the motor and pully white while they are still clean, and don't forget to check the idle speed all the time during the tuning process because some not all distributors still have mechanical advance weights in the distributor which will change the RPM while timing it and you want the idle speed and the timing to corespond to the book specs at the same time, because if your idle RPM climbs and you recheck the timing it will more than likely be off, and if you really want to get accurate never set your points with a feeler gauge always set your dwell angle it is way more accurate than a feeler gauge on the points and in essence they are the same thing. I can set my points with a feeler gauge and the dwell angle will be off a couple of degrees and it will idle rough but set the dwell right and she will run alot smoother. One reason I know about this so well is I have a mallory dual point and it is all mechanical advance no vacuum unit, I have keys to set the mechanical advance pattern and number of degrees to advance the timing. I also have an MSD-6 unit for an oddfire but have never installed it, but the few I have had on other vehicles made an awesome improvement in starting driveability and fuel economy plus they will run a hotter coil and you can regap the plugs wider but you still have the points, but you can also use them on a HEI ignition with similar results. I had one one my old Duster with the electronic ignition and it was great.

[69CJ]

If it runs smooth you must have it all wrong! :) What's your idle speed? I notice the roughness more under 1000.

I drop it to about 550 when setting the timing and keep it at 650 for everyday running.

Before swapping the timing chain and changing to pertronix, getting a steady timing mark was impossible. After these mods, the timing mark is completely stable. I've played with the timing from 5* thru 8*, compensating for the altitude here. The engine runs good - just no programmed idle roughness that's descibed here... <sigh> Timing less that 5* starts getting backfire through the carb.

The closest I've came to recreating your descriptive put-put-put-ahh.... is when the engine is cold and barely running with a little choke. But once it warms up - it smooths out and purrs nicely...

[John A. Shows]

I'm with you 69CJ. Old Nixon, has never been clearly identifiable as an oddfire just based on a rough idle either. The engine, sits atop it's new mounts and doesn't shake or rattle hardly any. I'll admit when the muffler was shot, you could hear a little rumble, that made it sound like a V8, but that's all fixed now with the new manifolds and muffler and tailpipe.

[69CJ]

I'm with you 69CJ. Old Nixon, has never been clearly identifiable as an oddfire just based on a rough idle either. The engine, sits atop it's new mounts and doesn't shake or rattle hardly any. I'll admit when the muffler was shot, you could hear a little rumble, that made it sound like a V8, but that's all fixed now with the new manifolds and muffler and tailpipe.

There ya go.... 8) Another smooth one........

As I'm a Harley type as well, I absolutely LOVE loppy idles, just can't seem to get it on this particular 225.

As far as mufflers go, I ran el cheapo $13 specials from autozone. I'm running two as I currently have the headman header setup with 2" pipe all the way back to the corners. The headers are louder than the original manifolds and these mufflers compensate for that, but frankly - they sound kind of whimpy if you ask me. When these get crushed or wear out, I'll most likely go with something a little more throaty. It may just be my ears though.......(I kind of killed them over the years with lots of loud stuff).

[Boyink]

Wondering if the choice of cam is affecting smoothness? I do have an RV cam, but didn't think it affected things much at idle.

[barry]

Hi Boyink,

Mine is stock. Tuned to 5 BTC and runs smooth. Why the choice of the RV cam? What were you looking for from it?

Just curious.

[Boyink]

Why, MORE POWER of course! (wow - this silly board just popped up a message box to tell me I was shouting by typing in all caps...:)

Seriously, the truth is I bought this motor already "rebuilt", it already had the RV cam in it.

It strikes me that "smooth" or "rough" are purely subjective terms, and we could be describing the same characteristic in different ways. It'd be interesting to line up all these old gals and compare them to another.

[69CJ]

Come on over! The garage fridge is full!

[John A. Shows]

Dang it!!! Dang it!!! Dang it!!!

Doesn't it suck that we all live so far apart. Of course if we were all in the same town, we'd probably all stay in trouble with our wives, and what not, from all the group meetings, and parties, and trail rides.

Yeah, I live in Mendenhall Mississippi, and I've NEVER EVER even seen another Dauntless V6. I would kill to be able to compare old Nixon to a V6 sibling.

Boyink, I just got that same pop up about shouting with capital letters.

[Drjeepster]

What little I know of the engine is the timing. 1-6-5-4-3-2 This timing is what creates the characteristic lope of the odd fire. Odd fire is odd fire for this reason. The odd fire didn't become even fire until the mid to late 70's

[sparky]

What little I know of the engine is the timing. 1-6-5-4-3-2 This timing is what creates the characteristic lope of the odd fire. Odd fire is odd fire for this reason. The odd fire didn't become even fire until the mid to late 70's

Huh?

Where'd this come from, it's almost 3 years old!

That firing order isn't any different than another Buick V6, or even several I6 engines.

If you want to know what makes an OF an Odd Fire peruse Merl Howell's webpage linked from the V6 Tech Section of this page.

[Boyink]

Whooa! Zombie thread, back from the dead!! :shock: :shock:

Here's a mind-bender for ya...an even fire Buick V6 has the same firing order...:D

[zed]

Whooa! Zombie thread, back from the dead!! :shock: :shock:

Here's a mind-bender for ya...an even fire Buick V6 has the same firing order...:D


yup.. that's what confused me at first :D

my oddfire has a nice gentle lope to it at idle of about 650rpm. smooths nicely once it's hits about 800 or 900. great torque at idle and low range!

[67cj5]

I had my timing around 6-8 and it ran great, except it lacked that v8 power i love so much, but it idled fairly smooth with the factory cam. I only installed the high torque cam because P.o. Gave it to me new in the box when i purchased the JEEP along with the Offy intake, but with/without cam I really didnt notice and erratic, or loppy idle. I did notice a crisper throttle response after installing the cam however.