The crossed fingers 360

derf · Post by **derf** » Tue Jun 06, 2017 7:24 am

Keep the gears together. They are a matched set.

Alternatively, if you can find a good quality set of replacement gears, you can use them. I was able to get a set of MSD (I think?) gears for my build. Though I think I heard that they were out of stock for at least a while.

tedlovesjeeps71 · Post by **tedlovesjeeps71** » Tue Jun 06, 2017 9:28 am

derf wrote:Keep the gears together. They are a matched set.

Alternatively, if you can find a good quality set of replacement gears, you can use them. I was able to get a set of MSD (I think?) gears for my build. Though I think I heard that they were out of stock for at least a while.

Thanks, will do.
The disappearance of many AMC aftermarket parts is kinda disconcerting. I still haven't found another "good" timing chain set. The last one came from Summit for Walter. Tried to order another and they were out of stock. Tried Jegs and they say "discontinued".

Tatsadasayago · Post by **Tatsadasayago** » Tue Jun 06, 2017 1:34 pm

A few observations:
I agree with Nikkoromat that the bores appear to have been honed at some point. The spacing and angles are definitely not factory.
Those horizontal bands of differing color indicates the rings have been 'fluttering' as the piston rose and fell.
The pistons don't look like the originals and I wager once you clean the gunk off the tops you will find an oversize marking.
The chambers and valves tell me the engine was burning oil. Most likely from the rings but worn valve guides and missing intake valve seals can be a factor.
The lifter valley is exceptionally clean and this is one more reason to suspect the engine has been apart before.
It may just be a chunk of carbon, but looking at cylinder #7 has what appears to be a pencil-eraser sized hole at the 6:00 position...

As far as the timing set goes, hopefully you are aware that many aftermarket cam gears block off the oiling slot and if not matched, will destroy the dizzy gears in short order. The commonly available Crown dizzy gears are soft and if you can find them, the MSD gears are the bees knees.
I used the bulltear double roller timing set and it was perfect.
http://www.bulltear.com/catalog/product ... c1203a9de8

There was a large batch of GM style HEI distributor shafts with the drive gear roll pin hole drilled incorrectly. If the dizzy was previously installed, you shouldn't have a problem there.

Thanks for sharing and keep the photos coming.

tedlovesjeeps71 · Post by **tedlovesjeeps71** » Tue Jun 06, 2017 2:43 pm

@Tatsadasayago... Will you adopt me!?!?!? Lol! Great eyes and excellent info... THANK YOU!
I really hope what you saw in #7 is just some funk that fell in. Today I'll be taking the bottom end apart and will look carefully. Crossing fingers it isn't bad.
These a guy in a different class building a 304 for his friend. Motor has over 300k on it and has two bad pistons. Hoping mine is much better. Previously rebuilt would be nice.
Not sure why a rebuilt motor would have so much slop in the timing chain though... It's pretty bad. I'd guess 3/4-1" of play?
I'll post up again tonight. Fingers crossed.

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tedlovesjeeps71 · Post by **tedlovesjeeps71** » Tue Jun 06, 2017 3:04 pm

Oh, forget to add my fight with that block heater. There is a brass screw that goes through the center. We fought that damn thing for like 20 minutes last night and ran out of time trying to get it out. Maybe I'm missing something but it sure doesn't want to come out!

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Cheap Hobby · Post by **Cheap Hobby** » Tue Jun 06, 2017 3:12 pm

Cloyes or melting timing sets are available from rock auto. Best prices in a quick look. Melting offers at least 3 different widths. If you have to replace drive gears for distributer msd 8005 and 8007 are the only ones to use.
For the Sandy deposits in the water jackets you can clean those out before the bath with long screw driver or wire rod and a vacum. Most of the cleaning units do not get the jackets clean. Even hot tanks leave a lot behind.
For the block heater brute force will be required. It is soft aluminum with an oring after numerous heat cool cycles it tends to weld it self to the block.

tedlovesjeeps71 · Post by **tedlovesjeeps71** » Tue Jun 06, 2017 4:37 pm

Because I was concerned I came to school a little early and took some pics of the pistons. As far as I can tell, whatever T saw that looked like a hole was just some funk? No holes that I see.
#7

#5

#3

#1

#8

#6

#4

#2

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Cheap Hobby · Post by **Cheap Hobby** » Tue Jun 06, 2017 5:27 pm

The oversize on those piston will be stamped in the recessed circle on the top. I can see 00 on one of themy but not the rest of the size.

Tatsadasayago · Post by **Tatsadasayago** » Tue Jun 06, 2017 5:27 pm

I assumed it was number 7.

I opened the image in Photoshop, zoomed in and did some levels tweaking.
Now it looks like some carbon chipped out and not a hole like I first thought.
My bad

tedlovesjeeps71 · Post by **tedlovesjeeps71** » Tue Jun 06, 2017 10:17 pm

So this is an interesting motor to say the least. We got it all torn down tonight and I'm trying to get stuff cleaned up. While it's been suggested that this motor was previously rebuilt I can squash that now. The crank and rod bearings as well as the pistons are original. The bearings have AMC stamped in them. It's also evident that there are some miles on the bottom end. The buildup on the pistons are pretty good examples of that. The oil rings, however, need replacing.

So here's where I get confused. How can the bottom end be so "used" yet the intake valley be so clean? Head gasket job maybe? Ok, so how is it that the block looks like it was cleaned and all the coolant passages are super clean and the freeze plugs look fairly new-ish? And why is there no paint on the block?
Weird.
So what did I discover so far. The crank and rod bearings look good. Cool.
The cam bearings however... Not so much.

Thankfully the instructor for the performance class is in the same building and is happy to help me change them out.
We pulled some measurements on the cylinder bores for taper but I haven't had a chance to look the results up and compare it to specs. Here's the numbers if you can read them and have any idea?

I also took a couple pics of one cylinder bore. It's not as nice as I'd hope but maybe it can be honed and work ok??

Last thing I got for tonight is the timing set. I can only guess it's the original since it's so sloppy. But I took pics so I can compare it with an aftermarket option. I don't see any wear on the gears so I'm wondering if I can get by with just a chain? Anyone have a recommendation for that or a reason not to?

I plan to go in tomorrow very early. I'm going to hit the morning class about half way through when they should be out in the shop. Hopefully I can get left alone and get to scrubbing the nasty off the parts and start some stuff going through the big dishwasher machine. More to come...

babywag · Post by **babywag** » Wed Jun 07, 2017 8:10 am

Timing chains on these are always loose if any miles on motor. I've never found a good one in an AMC

Just replace the gears to, there is wear on them. It's probably the originals. You can do just a chain but I'll wager it wouldn't be tight like a complete set.

tedlovesjeeps71 · Post by **tedlovesjeeps71** » Wed Jun 07, 2017 1:42 pm

Well that was mostly a wasted trip. Since I was visiting the daytime class I had to allow them to get their parts in the washer before me. By the time they were done I was only able to get the heads and timing cover in for a short run. I'll have to go back tonight and try some more.

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tgreese · Post by **tgreese** » Wed Jun 07, 2017 2:16 pm

tedlovesjeeps71 wrote:...
I also took a couple pics of one cylinder bore. It's not as nice as I'd hope but maybe it can be honed and work ok??
...

My understanding - the main problem with bore taper is with the rings. With tapered and/or out-of-round bores, you must use cast iron rings. Any higher-spec ring like moly or chrome may not seat in a tapered bore. The cast iron rings are not as durable as the higher-spec rings, so you'll take a penalty in lifetime there. Also, the tapered bore is said to make the rings fatigue faster, due to the increased flexing as the ring travels in the bore. So that too will shorten expected ring life.

If it were mine and I were in your shoes, I would go ahead and hone and re-ring with the original pistons. Pistons are the single most expensive item in a rebuild, so if money is tight, you kinda have to reuse them and accept the shorter ring life that will result.

Tatsadasayago · Post by **Tatsadasayago** » Wed Jun 07, 2017 3:56 pm

To add to what Tim wrote:
Since your taper appears to be .006" at the worst cylinder and less across the others; you could cut what little ridge there is and employ a bar hone to open up the lower part of the bore so there is no taper. This will increase the life of your rings substantially. A ball hone won't be as effective because it conforms to the bore whereas the bar hone uses 3 or 4 flat stones.
Although less expensive than boring, the downside to going this route is the procedure is very labor intensive.
As it was said, cast iron rings are the ticket here and if properly maintained, it's not unreasonable to expect 30-40k miles from an engine 'Freshened Up' in this manner.

tedlovesjeeps71 · Post by **tedlovesjeeps71** » Wed Jun 07, 2017 4:10 pm

Hmm... Lots to think about now. Thanks for the feedback guys. Honestly, I wish I had the money to just get a full kit and rebuild the thing right. Unfortunately, time and money are both against me here. I have to go Friday to do tags and a new license at the DMV. That will kill whatever "spare" money I have. And since we are halfway through this class I'm sure we will begin the assembly portion very soon. There won't be time to send it out or even order parts had the money been available. I guess the best thing to do for now is get it as clean as I can. When I get to the next engine class, hopefully I'll have money by then and can do it right.
So if you had to send it to the machine shop for work, what would you have done?

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tedlovesjeeps71 · Post by **tedlovesjeeps71** » Wed Jun 07, 2017 10:12 pm

So this is cool. There's a guy in the advanced class building a 304 for a friend. He got his master build kit in today and we got to talking. Unfortunately he has a couple cylinders that are bad so he has to bore it out to 30 over. He asked how mine was coming and I mentioned my cam bearings. He came over to look and says "hang on a second... I'm not using the ones in my kit. Do you think they are the same?" We do a quick Google and whaddya know, they are the same! He goes here ya go, merry Christmas!

I also had the high performance instructor come look at the block. Hes much more of a gear head than my instructor and is all about some "old technology" of overhead valve, push rod motors. Since we haven't actually cleaned the block he suggested we run it through the washer then ball hone the cylinders. Then remeasure to see what the cylinders actually look like. Not saying the guys helping me with my motor don't know anything but they often wander away out of boredom. They also don't have a lot of experience turning wrenches so I'm hoping they just screwed up measuring a dirty motor. If that's the case, I'll revisit the idea of going forward with this motor. The biggest expenses will be new rings and a timing set. Then gaskets and freeze plugs. I'd really love to get this thing together as a good, slightly warm, fresh motor.

As far as actual progress today, mostly just more cleaning. Heads are pretty clean and the gaskets scraped off. Also pulled the metal thing off the bottom of the intake manifold. The crank and old cam took a ride in the washer as did the pistons and rods. The crank is pretty clean but the pistons need more love. The cam I'm not concerned about since it's being replaced. I also sent the oil pan and valve covers through a quick cleaning but they need much more attention.

I have a question about the oil fill tube in the old intake. I'm guessing that has to be removed somehow to be installed into the edelbrock performer, right? How does it come out??

Tatsadasayago · Post by **Tatsadasayago** » Thu Jun 08, 2017 1:35 am

The filler tube is simply a compression/friction fit into the manifold. Often when installing it on a new Edelbrock a small bit of form a gasket keeps it in place.

Good to hear most of the bits are savable.

sonoraed · Post by **sonoraed** » Thu Jun 08, 2017 5:46 am

I rebuilt the 360 in my 79 J10 back in 2000 and oil mod was the one thing I really really regret not doing, although the oil pressure was always good I twice had to replace rear main bearing and #7 & 8 rod bearings, caught it way before any problems, as a side note before I rebuilt was looking for a good used engine and every engine I got from the wrecking yard rear main and 7/8 rod bearings were on their way out, Cheers

tgreese · Post by **tgreese** » Thu Jun 08, 2017 8:48 am

tedlovesjeeps71 wrote:... whaddya know, they are the same! ...

Should be. The 360 is a 304 with a larger bore. Main difference, besides the bore, is the heads. The larger bore allows for larger valves, which the 360/401 heads have.

derf · Post by **derf** » Thu Jun 08, 2017 9:17 am

tedlovesjeeps71 wrote:I have a question about the oil fill tube in the old intake. I'm guessing that has to be removed somehow to be installed into the edelbrock performer, right? How does it come out??

As has been said, it's just pressed in. I whacked mine with a rubber mallet on the side back and forth a couple of times to break it free a little and then was able to just muscle it out. Then just use the rubber mallet to pound it into the new manifold.

If you're still interested in the aluminum valve covers, they're still taking up space in the garage.

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