a bit more grunt and trailering a 2k trailer with 2.73 is a tough challengedodgerammit 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.
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 specsdodgerammit wrote:1) Cam 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:2) intake selection.
EGR lower the combustion temperature, and reduces Nox (green house gas)dodgerammit wrote:I do not have emmisions, but isn't a good egr system actually beneficial?
Porting is good for high rpm, otherwise the important part is to make sure that the exhaust gasket clears the portsdodgerammit wrote:We all have heard port/polish, etc etc. Gonna be using stock manifolds.
for high revving enginesdodgerammit wrote:7) Oiling mod
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...dodgerammit wrote: Some on the AMC forum say it's a myth, however, I do know I have a lifter issue at 160K miles.
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 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.
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: 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 .
EGR will stay, then. I was already strongly leaning this way.letank wrote: EGR lower the combustion temperature, and reduces Nox (green house gas)
No porting for what I need.letank wrote: Porting is good for high rpm, otherwise the important part is to make sure that the exhaust gasket clears the ports
letank wrote: for high revving engines
So, follow the KISS method, a decent cam/intake and watch for the timing cover common issues.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.
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.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.
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.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.
Cheap insurance. What is a couple hundred anyway?Stuka wrote: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.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.
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.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.
Edelbrock cams haven't changed in decades but they are not "nearly identical" and never have been.Stuka wrote: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.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.
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 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?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.
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!