stalls

[Rescue Diver]

sure...

see post #19 this thread.

also posted on your thread on the HEI

Has pics and user name... I was also involved when the user had his engine failure.

I re read #19 and I again see your claim that the hardened gear damages V8 and I-6, and I again see the link to junkyardgenius. Is that page where I will find the I-6 case study?

Ok, after re re reading the page, the part at the very bottom adresses I-6. It has nothing to do with it eating the I-6 cam gear because it's too soft. He's saying the distributor gear doesn't line up correctly with the cam gear when doing an HEI swap on an I-6. I have no way of testing this for myself because my distributor was sold to me as a single unit with a special gear already installed to allow the HEI to work in my AMC 258 i6 / 4.2l . Mine seems to line up ok, and I pulled the distributor a couple times over the thousands of miles I've put on it and the gears still looks brand new.

What I have to disagree with as far as the comments on that page regarding tuning are as follows.

"10. Tunability.

B.You CAN NOT adjust the total amount of advance or retard in the centrifugal system of a factory GM HEI.
There is no provision for changing the total centrifugal timing.
You will have to remove the distributor, dissasemble the distributor, and use an aftermarket kit or grind, drill and relocat parts to change the totals of the centrifugal system.

Motorcraft distributors all have at least one centrifugal change built into them, and it can be accessed in 60 seconds with out removing the distriubutor.
This total tuning change can be custom set with a file or small grinder by the user with out removing the distributor from the vehicle."

This one stumps me? For starters, you would only need to grind or drill on an HEI if you wanted more than 24 degrees of mechanical advance, which I doubt any AMC 258 i6 / 4.2l owner would want. And why is it better to grind or file on a Motorcraft distributor than on an HEI?

"C.In a factory GM HEI there is no tuning of the vacuum advance. Peroid.
GM made NO provision for either tuning or limiting the vacuum advance from the factory."

False, or at the very least nit picking because adjustable ones are available and cheap. GM has different vaccum advance modules available and they're stamped with how many degrees they advance. Furthermore, adjustable Vaccum Advance modules are available just about anywhere that simply take an allen wrench to adjust.

I'm sorry but it's obvious that the site we've been discussing has a bias towards other distributors than an HEI. I'd really be interested to see if there is any other web site that can be found that will back up the claims?

I wouldn't go to the Huffington Post to get reliable info on Republicans after all.

 

[Rescue Diver]

Here's a reliable source for tuning an HEI.

Setting Timing Curves - Tech, How-To, Ignition Timing Help - Hot Rod

 

[Petescj]

 

[Rescue Diver]

Has pics and user name... I was also involved when the user had his engine failure.

I'm confused. Maybe you can help me. The case study with pics and a user name on that page is about a V8? It clearly shows side by side V8 cam gears with the user's name. Is that the one you helped with?

The pics of the differing I-6 distributor gears at the bottom of the page don't have a user name attached. Which one were you involved with???

 

[Rescue Diver]

Here's another site with info on HEI swaps for the AMC 258 i6 / 4.2l .

GM HEI Distributor on Jeep 258 I6 Engine

 

[Rescue Diver]

And another good site for info on the HEI in a AMC 258 i6 / 4.2l .

GM HEI Installation

****EDIT****

This site says to use the older AMC 258 i6 / 4.2l Prestolite AMC 258 i6 / 4.2l distributor's gear because the later AMC 258 i6 / 4.2l Motorcraft gear won't work. Maybe that's the problem Junkyard Genuis was talking about? Could it be that he was saying the Motorcraft gear didn't work and he wasn't aware of the older model Prestolite gear? I'll have to go look at his page again to see if he says what distributor that mis-aligned gear came from.

 

[Petescj]

<< now eating the large popcorn :lpopcorn:

 

[Rescue Diver]

I looked at junkyardgenius again and he doesn't mention what AMC 258 i6 / 4.2l distributor gear he was refering to being used on an HEI, but since he's all about the Motorcraft distributors, I'd say it's at least possible that he isn't aware that the Prestolite distributor's gear is the correct one to use. Of course I could be wrong about this because it's just a guess based on him not giving the specific gear or part number.

 

[Cheepjeep85]

<< now eating the large popcorn :lpopcorn:

ease up pete you'll make yourself sick.

 

[Rescue Diver]

<< now eating the large popcorn :lpopcorn:

No popcorn required.

I'm just seriously trying to find out if there is in fact any reason to be concerned having an HEI in a AMC 258 i6 / 4.2l . I know the advance curve isn't an issue because they are quite easy to tune. If the gear is a problem, I would really like to know about it. So far I haven't seen any proof other than a couple pics of distributor gears on only one site, and that site doesn't say whether he's talking about the Motorcraft gear, which other sites say won't work, or if he's talking about the Prestolite gear which is supposedly the gear that will work just fine for swapping an HEI to a AMC 258 i6 / 4.2l .

 

[Rescue Diver]

I found this from Offroaders.com. They make no mention of the V8 cam gear issue, but I believe that's because the distributor they bought probably had a factory style soft gear that would match up well with it.

This article does a great job of showing the pros of the HEI and the cons of the motorcraft. This is just their opinion, but I agree with it.

Installing HEI Distributor Jeep CJ-7 AMC 360 V8

 

[Rescue Diver]

One last thought. All the negative info on the HEI upgrade for the AMC 258 i6 / 4.2l have seemed to originate with the one web site that was mentioned earlier. Every single forum I've found where the reported problems with the HEI upgrade have been discussed had a link back to this one site. It's the source of it all. Everyone else seems to be just repeating what they read on that one site!

That site says, and I quote,

"C.In a factory GM HEI there is no tuning of the vacuum advance. Peroid.
GM made NO provision for either tuning or limiting the vacuum advance from the factory."

This is mis leading because HEIs do have available adjustment for the vaccum advance.

Here are a couple pics of my dirt cheap less than $60 brand new HEI with its easily adjustible vaccum advance canister. It simply takes an allen wrench through the vaccum tube to tighten or loosen the spring.

 

[TrebleHook]

This post couldn't have been better timed...not trying to hijack but I've got/had similar problems....

After my CJ/AMC 258 i6 / 4.2l /MC2100 stalled out in the rain, an HEI was swapped in. Instantly solved whatever ignition problem I had, but it ran horribly at any speed higher than 50mph. It would sputter under any load. It was described by the mechanic who bled my brakes as "Spark Knocking" (which made me chuckle a bit).

So I backed out the secondary screw? (had to look this up!) and it got a little better but it still sputtered.

On the way home today, I had a thought and a guess....keep in mind I don't know diddly about carbs/engines. I wondered if perhaps the distributor was failing to advance properly due to Limited vacuum. Well I pulled over and pulled the vacuum line to the distributor. It had very weak suction.

I felt a few of the vacuum ports on the carb (most are capped so I just uncapped them and tested them) and found one that had better vacuum. Plugged the distributor into that one. Drove off.....problem solved. No more knocking. Seems to run smooth and strong not matter how hard I am pushing it. Starts strong.

Oddly, however, when I was driving to 7-11 tonight (2 minute trip) I was in 4th and got the RPMs pretty low going slow and it stalled out just driving down the road. Pulled over and it started after 2-3 tries and ran fine. Glitch?

Any thoughts? After reading the above, I am afraid I screwed something up.

Thanks!

Cheers,
TrebleHook

 

[IOPort51]

I am afraid the ones you posted are just, almost readable and the ones I have in front of me are for an 81. The 81 is a bit vague about what the two lines are for in fact they don't say squat. It looks, from what I can make out, that they are the same except for the legend. I have swapped the distributer from ported to manifold vacuum and am very impressed with the results so far, I am getting a bit of pre ignition and am considering dropping the advance a degree or 4. The 81 not only has the distributer running on port vac it has it being controlled by the CTO switch. I ordered a new timing light, a digital set back with tach. $100 well spent I hope.

Auto and Std Transmission .... see first graph legend

Just to clear..... This is the JEEP Field Service Manual, FSM, page from 1979 CJ.

Confused.... this is the FSM page... if you have a computer year of FSM it will not have this curve. The car is tuned at 1600 rpms and the computer will TAKE TIME ADVANCE OUT..... OUT ONLY..... as it sees fit from knock sensor, O2 sensor, temp and adj carb meter rods at same time.... Good at that is you have whole system.

I think you maybe saying your FSM has two lines also as does MY FSM chart scanned and shared above.... if that is the case than we are covered.

 

[MN CJ7]

I am afraid the ones you posted are just, almost readable and the ones I have in front of me are for an 81. The 81 is a bit vague about what the two lines are for in fact they don't say squat. It looks, from what I can make out, that they are the same except for the legend. I have swapped the distributer from ported to manifold vacuum and am very impressed with the results so far, I am getting a bit of pre ignition and am considering dropping the advance a degree or 4. The 81 not only has the distributer running on port vac it has it being controlled by the CTO switch. I ordered a new timing light, a digital set back with tach. $100 well spent I hope.

Sorry... the scan does make it look small.....
Look for ZOOM.... or a page item in your tool bar on top of page... if you cannot see one or find.... HIT F1 key (top lef key on keyboard) that is the quick key for help in many programs... Will give you a index and ask for zoom or page zoom and should show you how with your computers windows version.

The advance graph can be blow up to 200% and still look ok... and it is much more readable.

I have the 79 Book and not super clear on Auto/STD Transmission ... I would guess the auto curve to be more conservative and be the bottom curve... std on the top... I will also take another look at FSM and to see if any verbage in book for ya

I like ported over the manifold....Manifold will have vac at starting and when the throttle plates are closed..... Ported will not see vac when the throttle plates are closed

if you want to post some pics, desc what you have, carb, dist, years, controls you have left on removed. I would be happy to take a look.

My neighbor and I both have a digital time ligiht with advance indication... They do work, ck it against balance tape the first time you use and try to plot your curve. Getting the right advacne curve in there is HUGE adn will make a big diff on operation, pep, mileage.

There are some errors when not on use on 8 cyl and used on 6 cyl but not great.... use it on 4 cylinder and the error get at little to big not to verify with the time tape.

My system is pretty simple vac wise... I have the carb, PCV, distributor advance on ported, vac brake booster. My advance matches curve pretty close... comes in tad faster but very close... I run 5 deg initial, would take 8 and run well too... but having max advance not always optimal... my starts are much better at 5 deg initial...

 

[MN CJ7]

This post couldn't have been better timed...not trying to hijack but I've got/had similar problems....

After my CJ/AMC 258 i6 / 4.2l /MC2100 stalled out in the rain, an HEI was swapped in. Instantly solved whatever ignition problem I had, but it ran horribly at any speed higher than 50mph. It would sputter under any load. It was described by the mechanic who bled my brakes as "Spark Knocking" (which made me chuckle a bit).

So I backed out the secondary screw? (had to look this up!) and it got a little better but it still sputtered.

On the way home today, I had a thought and a guess....keep in mind I don't know diddly about carbs/engines. I wondered if perhaps the distributor was failing to advance properly due to Limited vacuum. Well I pulled over and pulled the vacuum line to the distributor. It had very weak suction.

I felt a few of the vacuum ports on the carb (most are capped so I just uncapped them and tested them) and found one that had better vacuum. Plugged the distributor into that one. Drove off.....problem solved. No more knocking. Seems to run smooth and strong not matter how hard I am pushing it. Starts strong.

Oddly, however, when I was driving to 7-11 tonight (2 minute trip) I was in 4th and got the RPMs pretty low going slow and it stalled out just driving down the road. Pulled over and it started after 2-3 tries and ran fine. Glitch?

Any thoughts? After reading the above, I am afraid I screwed something up.

Thanks!

Cheers,
TrebleHook

I mentioned this the other day on what carb to get... the Motorcraft 2100 guys were on there...

I had a 2100 carb here at my home... I had the same issue could not get the vac advance to move on distributor.... it can be seen if you look at the arm/pivot point will move. Looking at the carb from CJ grill... ported on left side.....YEP look right....

I took that carb off 3 times to ck the passages and see why I could not get vac levels... I would give me some/little at idle... give it some gas and the vac level went to zilch. This was a REFURB 2100 FROM CALF... this guy said hundreds per mo... they do 2100..... He had no ans for me. My VAC GAUGE does not lie ... it fell of to zilch and I have the Vac# written down on his 'sheet". I went looking for second ported source that worked correctly... It was on the other side... the right side. Cannot tell you the exact one...... it was so ODD ... I made a video and still have it somewhere.

Adj your 2100 screws again... they need to be the same turns both of them... and max you vac levels...need a vac guage. Adj your time again. The vac level on stock dist is adj if need with the allen set screw in the vac can input hole.

Not sure how common this is in 2100 but I worked on one, you worked on one, 2100 Refurb did not know what to tell me... but he knows now too.

I put a vac gauge on that right port... it was a ported vac source.


Fred



take a guess on 7 11 store visit... the manifold was not up to temp yet and that could be the issue... Take a bit for the coolant to heat the intake manifold and there is also a electric heater in there too... its goes on to warm up under the carb till the coolant has intake up to temp...

Soo cool you are running better.

 

[Rescue Diver]

My vaccum advance works ok from the ported vaccum on my MC2100. That's a weird one?

 

[MN CJ7]

exactly... a odd ball 2100, not the NORM
There was one now there are two... might be more.

 

[Rescue Diver]

exactly... a odd ball 2100, not the NORM
There was one now there are two... might be more.

There are more than a few people on this forum and countless others that are using MC2100 and MC2150 carbs without any problems at all. It's just about the most comon swap on a AMC 258 i6 / 4.2l for more reasons than their cheap price. They're so simple to build and tune, a caveman could do it!

 

[Cheepjeep85]

i use one and my vac advance works fine, no issues with that.