Planning a 360 motor build (1st fire and break in DONE!!!)

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dodgerammit
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Planning a 360 motor build (1st fire and break in DONE!!!)

Post by dodgerammit »

Hello all.

After new exhaust gaskets, I'm still getting the dreaded faint ticking noise that will go away after warm, but returns under load.

Sounds like I am in the early stages of a collapsing lifter.

Spoke with the local machine shop about a cam swap, but he strongly recommended just doing a rebuild since I'm at 160K miles. The rebuild would be about a grand more than a cam swap and resealing all of the leaks (and it has a bunch).

This will all be happening to Radio Flyer (in sig).


So, with that on my radar, I'm naturally wanting a bit more grunt and pep. Realistic pep over the smogged down stocker. I am running 2.73s, so that is part of the problem.

I am wanting reliability, longevity, and some torque to comfortably tow 2K (think pop-up camper) over a local mountain 5-6% grade.

Shooting for a small bump in compression (something I can safely run on mid grade most of the time).

Running stock duraspark dizzy with MSD streetfire. Don't intend on changing that up.

Also don't want to lose the economy I currently have (12-15mpg town/hwy driving).
Anything to help that would be appreciated, but I'm not asking for a miracle.


So, the build is tentatively scheduled for fall. I am reading and deciding on parts selection.

Of course, the famous cam/intake selection. I want a quality cam. I know of the summit 8600, the edelbrock variant (performer plus?), then there are others. Some have had quality control issues, hence my concern. Will also probably talk with the guy at the shop as he is knowledgeable about building performance engines and he doesn't try to sell what I don't need.

While out, he will install a new front pump in the transmission.

1) Cam selection.

Low end torque, made for slightly better compression, designed to work in the RPM band of the automatic.

What is the RPM band of this puppy anyway?

2) intake selection.

Seems the consensus is the edelbrock. There is the 2131 non EGR and the 3731 EGR version.

I do not have emmisions, but isn't a good egr system actually beneficial?

3) Carburetor

A 600cfm vacuum secondary in my flavor to match EGR setup I choose.

4) piston selection

Here is where I am torn. I've read slightly bumped compression with stock heads is a great thing, and also I've heard just stay stock for reliability.

Help me out here. What are some good quality sets? Are forged worth the expense for what I want?

5) Porting stock heads

We all have heard port/polish, etc etc. Gonna be using stock manifolds.

Is it worth it for what I'm wanting?

6) strengthening weak areas

Probably going to splurge on Bulltear for their oil pump/midplate/nickle-plated timing cover. http://www.bulltear.com/catalog/product ... cts_id=136

Any reason to not do this? I can't think of one. What about the little add-on stuff like HRC gear, etc?

Anything else to address?

7) Oiling mod

Some on the AMC forum say it's a myth, however, I do know I have a lifter issue at 160K miles.

So, what is the consensus here? It would essentially be cheap insurance regardless.

I'm sure more questions will be asked in future posts.

Thanks!
Last edited by dodgerammit on Mon Jun 15, 2020 11:42 pm, edited 2 times in total.
84 Grand Waggy-Radio Flyer (Garnet Red/3M Ebony Metallic woodgrain, with honey interior) AMC 360 :cry: 2004 4.8LS/Advance Adapter/727/242 D44/AMC20 Serehill tailgate and headlight harnesses :fsj: Ongoing thread-viewtopic.php?t=11897

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letank
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Re: Planning a 360 motor build (parts gathering phase)

Post by letank »

dodgerammit wrote:
a bit more grunt and pep. Realistic pep over the smogged down stocker. I am running 2.73s, so that is part of the problem.

I am wanting reliability, longevity, and some torque to comfortably tow 2K (think pop-up camper) over a local mountain 5-6% grade.
a bit more grunt and trailering a 2k trailer with 2.73 is a tough challenge
dodgerammit wrote:1) Cam selection.
I ordered a bunch of cams after surfing all the suggestions from this site, the mothership and theamcforum, the comp cam was badly rusted, the edelbrock did not have a cam card, and the third choice was the melling, off ebay at $90ish, need to find the exact specs

for the MTA1, exhaust duration at 0.50 lift is 214 degrees and intake duration at 0.50 lift is 204 degrees which are the important values, the exhaust and intake duration of 289 and 280 degrees are the other data, but the real one is the one measured at 0.50 lift when the cam is starting its opening cycle. The stock is around 196.
dodgerammit wrote:2) intake selection.
I initially had an edelbrock, but did not want to break in the cam with an unknown 600cfm edelbrock 1400 series and could not find the right spacers for the 2150, after reading all the stories, the 2150 seems the better choice for altitude changes... I have 3.31 gearing, the towing specs as labelled by the tag on the dana 44 .
dodgerammit wrote:I do not have emmisions, but isn't a good egr system actually beneficial?
EGR lower the combustion temperature, and reduces Nox (green house gas)
dodgerammit wrote:We all have heard port/polish, etc etc. Gonna be using stock manifolds.
Porting is good for high rpm, otherwise the important part is to make sure that the exhaust gasket clears the ports
dodgerammit wrote:7) Oiling mod
for high revving engines
dodgerammit wrote: Some on the AMC forum say it's a myth, however, I do know I have a lifter issue at 160K miles.
I had a lifter failed on the 74, replaced only the lifters at 200K .... kept going until 349K... retired due to rust on the A pillar, and some blow by on the engine... and got another FSJ...

On the 86 project I had a slight knock, and it was the a couple of cam lobes that self destructed due to dirt , coming from the missing filter foam on the oil filler cap
Michel
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85 Gwag (229 Kmiles... the running test lab)
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Re: Planning a 360 motor build (parts gathering phase)

Post by dodgerammit »

Thank you for the reply.



a bit more grunt and trailering a 2k trailer with 2.73 is a tough challenge[/quote]

Agreed. as far as I'm concerned, the potential for a regear sometime in the future is a possibility, but would come with the hefty price of an OD swap.


letank wrote: I ordered a bunch of cams after surfing all the suggestions from this site, the mothership and theamcforum, the comp cam was badly rusted, the edelbrock did not have a cam card, and the third choice was the melling, off ebay at $90ish, need to find the exact specs

for the MTA1, exhaust duration at 0.50 lift is 214 degrees and intake duration at 0.50 lift is 204 degrees which are the important values, the exhaust and intake duration of 289 and 280 degrees are the other data, but the real one is the one measured at 0.50 lift when the cam is starting its opening cycle. The stock is around 196.
So pay attention to specs at .50 lift for exhaust and intake. So what would be a good range? I'm guessing low 200s for strong idle? Of course, I can also pick the machine guy's brain.

letank wrote: I initially had an edelbrock, but did not want to break in the cam with an unknown 600cfm edelbrock 1400 series and could not find the right spacers for the 2150, after reading all the stories, the 2150 seems the better choice for altitude changes... I have 3.31 gearing, the towing specs as labelled by the tag on the dana 44 .
I do like the 2150, don't get me wrong. It starts with one pump of the pedal. Every time. But, the warm up time is horrible compared to other carbureted vehicles I have driven. Of course, this is a reman, so the quality may be a bit sub par.

letank wrote: EGR lower the combustion temperature, and reduces Nox (green house gas)
EGR will stay, then. I was already strongly leaning this way.

letank wrote: Porting is good for high rpm, otherwise the important part is to make sure that the exhaust gasket clears the ports
No porting for what I need.

letank wrote: for high revving engines


I had a lifter failed on the 74, replaced only the lifters at 200K .... kept going until 349K... retired due to rust on the A pillar, and some blow by on the engine... and got another FSJ...

On the 86 project I had a slight knock, and it was the a couple of cam lobes that self destructed due to dirt , coming from the missing filter foam on the oil filler cap[/quote]

So, why the all of the notorious issues with the top end of these blocks? This seems to be the rule rather than the exception.
84 Grand Waggy-Radio Flyer (Garnet Red/3M Ebony Metallic woodgrain, with honey interior) AMC 360 :cry: 2004 4.8LS/Advance Adapter/727/242 D44/AMC20 Serehill tailgate and headlight harnesses :fsj: Ongoing thread-viewtopic.php?t=11897

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Re: Planning a 360 motor build (parts gathering phase)

Post by babywag »

The oiling line mod came about for race engines. Supposedly @ HIGH RPMs the rear main bearings can starve for oil.
This particular modification is not needed unless you are flat out racing down the 1/4 mile.

The RV grind cam is a good cam, Edelbrock performer, Melling MTA-1, Elgin 912, etc. All are likely ground by same place and just reboxed.
With that cam a 4bbl and good exhaust, it makes for a very nice engine.
But there are many many choices and opinions out there for cams.

You can port/polish heads, but any gains will be minimal/small unless you're building a wild child.
Headers are proven to add horsepower, but if you want to stay with stock cast iron manifolds a little porting and true duals or good diameter single system will help too.

I personally wouldn't bother with an aftermarket timing cover or the midplate. Several people have had issues with aftermarket covers.
Most of the time the stock timing cover just needs to be redone, returning it to the correct specs.
There are articles online on what needs to be done/checked.
Be sure your machinist knows how to check/refurb the timing cover out, and the timing gears for the common oiling issues/problems.
This info is out there too, SC/397 has a bunch of pics posted on ifsja.org
I believe SC/397 will also blueprint your timing cover for you if desired.
-Tony
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Re: Planning a 360 motor build (parts gathering phase)

Post by dodgerammit »

babywag wrote:The oiling line mod came about for race engines. Supposedly @ HIGH RPMs the rear main bearings can starve for oil.
This particular modification is not needed unless you are flat out racing down the 1/4 mile.

The RV grind cam is a good cam, Edelbrock performer, Melling MTA-1, Elgin 912, etc. All are likely ground by same place and just reboxed.
With that cam a 4bbl and good exhaust, it makes for a very nice engine.
But there are many many choices and opinions out there for cams.

You can port/polish heads, but any gains will be minimal/small unless you're building a wild child.
Headers are proven to add horsepower, but if you want to stay with stock cast iron manifolds a little porting and true duals or good diameter single system will help too.

I personally wouldn't bother with an aftermarket timing cover or the midplate. Several people have had issues with aftermarket covers.
Most of the time the stock timing cover just needs to be redone, returning it to the correct specs.
There are articles online on what needs to be done/checked.
Be sure your machinist knows how to check/refurb the timing cover out, and the timing gears for the common oiling issues/problems.
This info is out there too, SC/397 has a bunch of pics posted on ifsja.org
I believe SC/397 will also blueprint your timing cover for you if desired.
So, follow the KISS method, a decent cam/intake and watch for the timing cover common issues.

I remember toothofwar having issues with his cam/dizzy gears and the timing chain sprocket being the issue. The slot on the chain either didn't line up with the oil hole in the cam, or the slot was too long, etc. Since I'm ordering parts, I'll probably check this before I drop the parts off.

I've also found a video on the tube about resurfacing the timing cover and oil pump plate using a piece of glass and some valve grinding compound. Looked simple enough.



I've also read about using a cam button to prevent timing cover wear issues.

Also there is an oil pump mid plate that is popular.

Should I check the timing cover specs before considering these items?
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Re: Planning a 360 motor build (parts gathering phase)

Post by 1979bettywhite »

For my rebuild/reman, I kept everything stock but went to the Performer Intake (non-EGR) and then spent the money for the Holley Sniper. I think that alone so far has changed the game for me completely. Response is great, feels so much stronger on the hills, and cruises nicely. OE was 2 barrel intake and 2150. I do recommend swapping the fixed linkage on the Sniper out for a progressive linkage.

As mentioned the 2.73s in the hills may continue to be an issue. I have great oil pressure after the reman and I am on the stock cover etc. I think oil pressure in these engines is more about the tolerances than about the pump. As my mechanics have told me, these engines, especially in stock form really don't require that much oil pressure. After my reman I get 60-70 initial start, 50 hot cruise and 20 at idle. Running VR1 10W-30. Before was at best 20 at hot cruise, maybe 5-7 at idle.

If you have a good machinist I would think that a good rebuild back to stock should really improve things for you in your desired use. I would think more towards the tranny and transfer case and gearing in regards to your towing intentions. Re-gearing will of course make the same engine feel a lot more peppy and tackle the hills much easier. Make sure you are able to adequately cool the tranny on those long uphill slogs. May want to add a temp sensor.
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Re: Planning a 360 motor build (parts gathering phase)

Post by dodgerammit »

1979bettywhite wrote:For my rebuild/reman, I kept everything stock but went to the Performer Intake (non-EGR) and then spent the money for the Holley Sniper. I think that alone so far has changed the game for me completely. Response is great, feels so much stronger on the hills, and cruises nicely. OE was 2 barrel intake and 2150. I do recommend swapping the fixed linkage on the Sniper out for a progressive linkage.

As mentioned the 2.73s in the hills may continue to be an issue. I have great oil pressure after the reman and I am on the stock cover etc. I think oil pressure in these engines is more about the tolerances than about the pump. As my mechanics have told me, these engines, especially in stock form really don't require that much oil pressure. After my reman I get 60-70 initial start, 50 hot cruise and 20 at idle. Running VR1 10W-30. Before was at best 20 at hot cruise, maybe 5-7 at idle.

If you have a good machinist I would think that a good rebuild back to stock should really improve things for you in your desired use. I would think more towards the tranny and transfer case and gearing in regards to your towing intentions. Re-gearing will of course make the same engine feel a lot more peppy and tackle the hills much easier. Make sure you are able to adequately cool the tranny on those long uphill slogs. May want to add a temp sensor.
Good news is that oil pressure is not a problem even now. 40 hot, 25 at cruise and 15 at idle. Yeah, it is the factory gauge, but seems to follow a realistic pattern when on/off throttle. That would indicate oil pump clearances should be good. The oil pressure was why I first considered an exhaust leak and not a cam/lifter issue.

I have already put an auxilliary trans cooler and deep pan on the list. Glad it is a 727. Aftermarket stuff for days. I guess a good sensor and gauge would be a nice add.

Thankfully, the uphill sections are minimal in the eastern US.
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Re: Planning a 360 motor build (parts gathering phase)

Post by Stuka »

babywag wrote:The oiling line mod came about for race engines. Supposedly @ HIGH RPMs the rear main bearings can starve for oil.
This particular modification is not needed unless you are flat out racing down the 1/4 mile.
When you pull apart an AMC V8, those rear mains always have more wear than the fronts do, same goes for the cam bearings. The oiling mod would still help in these. And if towing, or living in mountainous terrain, I think its also a worthwhile mod. But, not required.

Oh, and unless Edelbrock has made changes, their cam is nearly identical to stock. So don't go with that if wanting an upgrade.
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Re: Planning a 360 motor build (parts gathering phase)

Post by dodgerammit »

Stuka wrote:
babywag wrote:The oiling line mod came about for race engines. Supposedly @ HIGH RPMs the rear main bearings can starve for oil.
This particular modification is not needed unless you are flat out racing down the 1/4 mile.
When you pull apart an AMC V8, those rear mains always have more wear than the fronts do, same goes for the cam bearings. The oiling mod would still help in these. And if towing, or living in mountainous terrain, I think its also a worthwhile mod. But, not required.
Cheap insurance. What is a couple hundred anyway? :D
Stuka wrote: Oh, and unless Edelbrock has made changes, their cam is nearly identical to stock. So don't go with that if wanting an upgrade.
I'm thinking possibly a summit k8600? Comp 268H? Seems their quality control has improved? I just want a cam with minimal issues from AMC enthusiast real world testing.
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Re: Planning a 360 motor build (parts gathering phase)

Post by dodgerammit »

Here are some specs from Lunati on a couple differing profiles.

Their 260 cam:
Hydraulic Flat Tappet Cam. Factory replacement cam. Good off road, towing and economy cam. Smooth idle.

Advertised Duration (Int/Exh): 260/260
Duration @ .050 (Int/Exh): 210/210
Gross Valve Lift (Int/Exh): .470/.470
LSA/ICL: 110/106
Valve Lash (Int/Exh): Hyd/Hyd
RPM Range: 1000-4800
Includes: Cam & Lifters (#71977PR-16)


Their 268:
The High Efficiency Camshafts are computer designed for increased performance and improved fuel efficiency. These camshafts offer a substantial increase in low RPM performance while maintaining compatibility with most OEM computer controlled vehicles.Hydraulic Flat Tappet Cam. Daily performance and off road and 4x4 cam. Good idle.

Advertised Duration (Int/Exh): 268/268
Duration @ .050 (Int/Exh): 218/218
Gross Valve Lift (Int/Exh): .488/.488
LSA/ICL: 110/106
Valve Lash (Int/Exh): Hyd/Hyd
RPM Range: 1200-5200
Includes: Cam & Lifters (#71977PR-16)


Seems like they are under the .5 lift requirement for A quality street driven AMC.
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Re: Planning a 360 motor build (parts gathering phase)

Post by toothofwar »

When I tbi my 360 the timing gears was dry. There was 2 problems with my cam gear. One was the oil slot in the gear was off from the oil hole. The second was the concave area on the back was almost non existent. So I took a file and a die grinder and made it right. If you are replacing the timing set, have him check those tolarances.

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Re: Planning a 360 motor build (parts gathering phase)

Post by babywag »

Stuka wrote:
babywag wrote:The oiling line mod came about for race engines. Supposedly @ HIGH RPMs the rear main bearings can starve for oil.
This particular modification is not needed unless you are flat out racing down the 1/4 mile.
When you pull apart an AMC V8, those rear mains always have more wear than the fronts do, same goes for the cam bearings. The oiling mod would still help in these. And if towing, or living in mountainous terrain, I think its also a worthwhile mod. But, not required.

Oh, and unless Edelbrock has made changes, their cam is nearly identical to stock. So don't go with that if wanting an upgrade.
Edelbrock cams haven't changed in decades but they are not "nearly identical" and never have been.
They just rebox existing grinds under their label.
A stock 360 cam is .425/.425
An edelbrock performer or AKA "RV" cam is .448/.472
The performer rpm is .520/.545

Far as the oiling mod I have yet to see any proof it helps.
Torn down many 360s never saw unusual wear on 1 or 2 of the mains.
-Tony
'88 GW (aka Babywag)

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Re: Planning a 360 motor build (parts gathering phase)

Post by Cheap Hobby »

If you replace the oil filter housing and oil pump gears you won't need the mid plate. The mid plate gives a hard surface for the oil pump gears to wear against. You can also hand lap the stock filter housing and remove any wear. Recently tore down an abused 300k 360 and had very little wear. Unless you have chunks missing from the timing cover or a lot of wear from a bad chain cam button is not needed and time consuming to make. When the engine is torn down make sure the distributor gear is saved so it can be reused with gear on distributor.
Make sure your machinist knows the valve seats on these engines are the hardest and have to be ground with that in mind.
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Re: Planning a 360 motor build (parts gathering phase)

Post by dodgerammit »

I've been watching some youtube vids about the distributor gear and lining up the holes/slots. I think I have the concept down. I also seen the video about using a piece of glass and some valve grinding compound to resurface the filter housing and mating surface of the timing cover. Seems to be the timing cover is usually a reusable and preferred keep item.
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Re: Planning a 360 motor build (parts gathering phase)

Post by dodgerammit »

Hmmm. Schneider Cams 252-56H

Part Number: 30059
Grind Number: 252-56H
Intake Duration (gross): 252
Exhaust Duration (gross): 256
Intake Duration (.050”): 194
Exhaust Duration (.050”): 204
Intake Valve Lift*: .424"
Exhaust Valve Lift*: .448"
Lobe Separation: 110
Intake Valve Lash: .000"
Exhaust Valve Lash: .000"
RPM Range:
1000-3500
84 Grand Waggy-Radio Flyer (Garnet Red/3M Ebony Metallic woodgrain, with honey interior) AMC 360 :cry: 2004 4.8LS/Advance Adapter/727/242 D44/AMC20 Serehill tailgate and headlight harnesses :fsj: Ongoing thread-viewtopic.php?t=11897

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Re: Planning a 360 motor build (parts gathering phase)

Post by weeegoneeer »

I just built a 360 with the following:
- bored .030 over
- K1 forged rods
- Wiseco forged -21cc pistons
- Comp 260H
- Performer no EGR (I'm going to put a Sniper on it eventually)
- Holley SA 670 (I think it's too big but it's what I have)
- Stainless valves, machined for positive valve seals
- Hardened seats installed
- Everything was balanced as well
- Heads machined for studs & guideplates
- Comp roller tip rockers
- Stock exhaust

Intention was to have a very street overbuilt motor. CC'd the heads and they averaged out at 60cc, which will put me right at about 9:1 compression, not very high but higher than factory.

I should have it broken in this week, will let you know how it works out / how it feels.

2.73s are such a killer, my old wag had them. New one has 3.31s and it's a noticeable difference. It's not mindblowing, but it does get up and go a bit better.
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Re: Planning a 360 motor build (parts gathering phase)

Post by dodgerammit »

weeegoneeer wrote:I just built a 360 with the following:
- bored .030 over
- K1 forged rods
- Wiseco forged -21cc pistons
- Comp 260H
- Performer no EGR (I'm going to put a Sniper on it eventually)
- Holley SA 670 (I think it's too big but it's what I have)
- Stainless valves, machined for positive valve seals
- Hardened seats installed
- Everything was balanced as well
- Heads machined for studs & guideplates
- Comp roller tip rockers
- Stock exhaust

Intention was to have a very street overbuilt motor. CC'd the heads and they averaged out at 60cc, which will put me right at about 9:1 compression, not very high but higher than factory.

I should have it broken in this week, will let you know how it works out / how it feels.

2.73s are such a killer, my old wag had them. New one has 3.31s and it's a noticeable difference. It's not mindblowing, but it does get up and go a bit better.
I'm leaning heavily toward wiseco forged pistons and decking the heads to drop the cc just a bit. Been lurking on the amc forums and reading a bunch. Wanting between 9:1-9.5:1 compression. Forged pistons are cheap insurance against a bad tank of fuel. Most have said reuse stock rods. They have never seen them fail. I am interested in some minor head work, primarily seats for the valve seals. Any more info on yours?

3.31s look like a solid contender in the future for what I want out of this rig without going overboard.
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Re: Planning a 360 motor build (parts gathering phase)

Post by weeegoneeer »

If I were to do it again, I'd have them shave a bit more off instead of just cleaning it up. 9.5:1 would have been ideal, but I'm OK with where I'm at.

Valve Seals:
Machining for positive seals isn't a big deal or expensive. I like the thought of them more than the umbrella seals. Some guys just put positive seals on the intake valves.

Pistons:
What's good about the Wisecos is that piston to bore clearance only needs to be .003". I guess with most forged pistons you're looking at .006" or so, which can lead to noise until the motor heats up & the piston expands.

Rods:
About rods - I've been reading this site and the mothership daily for a bunch of years and have never seen anything negative about stock rods. With the forged pistons, you will need to have your existing rods machined to accept them. The K1s are beautiful rods though!

Head work:
For the head work, my thinking was:
- I want to run roller rockers to take the friction off the valve stem & increase the life of my valve guides
- To do that I had to get studs and guide plates
- Positive seals are better
- Stainless valves do not burn as easily (I think)
- 3-angle valve job because why not
- I didn't ask for the hardened valve seats, my machinist just did it as a matter of course. The valves now protrude a bit from the surface of the head, which is where I think I lost the 2 CCs from the stock 62CC combustion chamber. I read somewhere that AMC heads have hardened seats that go pretty deep, you may not need to do this.

Longevity:
My thinking around reliability and longevity was:
- Forged pistons - to withstand abuse (bad gas / etc)
- Stainless valves - less likely to burn?
- Cylinders bored/honed with torque plate - piston walls are closer to a perfect circle once heads are torqued on
- Went aluminum bearings. I guess they last longer for normal use, but may not be as good for lots of heavy loads? Lead babbit is preferred there.
- Balanced rotating assembly - just seems to make sense. If it's out of balance all bearings will be dealing with uneven loads
- Roller tip rockers - less sideways friction on valve stem = longer guide life
- Positive valve seals - less oil in chamber as valve guides wear
- Ground oil notch on cam timing gear to line up with oil hole in cam - that stuff needs oil!
- Brazed 5 of 6 oil slots shut on cam timing gear to make sure dizzy gets enough oil - 6 slots is overkill for a chain. You want that pressure going to the distributor gear.
- Rehabbed OEM timing cover - want to avoid alignment issues. I did get a bulltear timing over previously, and it leaked from the press fit idler shaft for the pump gear.

We're not racing a Javelin:
The port / polish / port matching / headers / oil mods I paid no attention to. The motor turns only 3200 if going 75 MPH, it never sees above that RPM. Less likely for you with 2.73s

Disclaimer:
Anyway, not an expert AT ALL, take advice with a grain of salt. This is just the first motor I've built myself and have done a bunch of research around it over the last 9 months, our goals seem similar. Can't stand behind any of my statements now out of personal experience, but hopefully can in 100,000 miles.

I am absolutely, completely terrified to light this thing off this week!
1984 GW
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dodgerammit
Posts: 1434
Joined: Wed Jan 11, 2017 11:20 pm
Location: Middle TN

Re: Planning a 360 motor build (parts gathering phase)

Post by dodgerammit »

weeegoneeer wrote:If I were to do it again, I'd have them shave a bit more off instead of just cleaning it up. 9.5:1 would have been ideal, but I'm OK with where I'm at.

Valve Seals:
Machining for positive seals isn't a big deal or expensive. I like the thought of them more than the umbrella seals. Some guys just put positive seals on the intake valves.


Head work:
For the head work, my thinking was:
- I want to run roller rockers to take the friction off the valve stem & increase the life of my valve guides
- To do that I had to get studs and guide plates
- Positive seals are better
- Stainless valves do not burn as easily (I think)
- 3-angle valve job because why not
- I didn't ask for the hardened valve seats, my machinist just did it as a matter of course. The valves now protrude a bit from the surface of the head, which is where I think I lost the 2 CCs from the stock 62CC combustion chamber. I read somewhere that AMC heads have hardened seats that go pretty deep, you may not need to do this.

Longevity:
My thinking around reliability and longevity was:
- Forged pistons - to withstand abuse (bad gas / etc)
- Stainless valves - less likely to burn?
- Cylinders bored/honed with torque plate - piston walls are closer to a perfect circle once heads are torqued on
- Went aluminum bearings. I guess they last longer for normal use, but may not be as good for lots of heavy loads? Lead babbit is preferred there.
- Balanced rotating assembly - just seems to make sense. If it's out of balance all bearings will be dealing with uneven loads
- Roller tip rockers - less sideways friction on valve stem = longer guide life
- Positive valve seals - less oil in chamber as valve guides wear
- Ground oil notch on cam timing gear to line up with oil hole in cam - that stuff needs oil!
- Brazed 5 of 6 oil slots shut on cam timing gear to make sure dizzy gets enough oil - 6 slots is overkill for a chain. You want that pressure going to the distributor gear.
- Rehabbed OEM timing cover - want to avoid alignment issues. I did get a bulltear timing over previously, and it leaked from the press fit idler shaft for the pump gear.

We're not racing a Javelin:
The port / polish / port matching / headers / oil mods I paid no attention to. The motor turns only 3200 if going 75 MPH, it never sees above that RPM. Less likely for you with 2.73s

Disclaimer:
Anyway, not an expert AT ALL, take advice with a grain of salt. This is just the first motor I've built myself and have done a bunch of research around it over the last 9 months, our goals seem similar. Can't stand behind any of my statements now out of personal experience, but hopefully can in 100,000 miles.

I am absolutely, completely terrified to light this thing off this week!

Very good info. Thanks, and good luck on your first fire (and everyone that follows!)
84 Grand Waggy-Radio Flyer (Garnet Red/3M Ebony Metallic woodgrain, with honey interior) AMC 360 :cry: 2004 4.8LS/Advance Adapter/727/242 D44/AMC20 Serehill tailgate and headlight harnesses :fsj: Ongoing thread-viewtopic.php?t=11897

92 Wrangler Islander 4.0/32RH/231 D30/D35 RHD
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dodgerammit
Posts: 1434
Joined: Wed Jan 11, 2017 11:20 pm
Location: Middle TN

Re: Planning a 360 motor build (parts gathering phase)

Post by dodgerammit »

Posting this for my info later. Summit M2008 600 vac secondary. Great reviews, seems to be easily tuned with available parts (Holley 4010 kit works), and deliver good mileage: https://www.summitracing.com/parts/sum- ... s/reviews/
84 Grand Waggy-Radio Flyer (Garnet Red/3M Ebony Metallic woodgrain, with honey interior) AMC 360 :cry: 2004 4.8LS/Advance Adapter/727/242 D44/AMC20 Serehill tailgate and headlight harnesses :fsj: Ongoing thread-viewtopic.php?t=11897

92 Wrangler Islander 4.0/32RH/231 D30/D35 RHD
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