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Discussion Starter #1
My poor 289 needs to either have the heads rebuilt, or replaced (soon) As I fear they have finally begun to experience the valves sinking. My question is should I rebuild the original 289 heads or I could buy a complete 302 shortblock for $100 and have put a valve job on the heads and mill them down a bit (dont want to lose too much CR)

I had a local machine shop give me a worse case scenario for the 289 head rework and they said around $700 (hardened seats, new vavle guides and valves), another shop said for same work (except new seats in the exhaust only) it should be $400.

What is people's thoughts on this?

ron
 

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For not much more than the $700.00 you were quoted you could get a pair of CNC ported heads from Power Heads. These are very nicely worked stock iron heads.

You only really need hardened seats on the exhaust ports, so you could save a little there.
 
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Discussion Starter #4
True aftermarket head are almost feasible when your talking about overpriced head work. But the other things I must consider are things like the nice blue clouds that come out of the exhaust every once in a while (either vavle stem seals *wishful thinking*) or oil control rings. And since oil pressure drops to the bottom of the gauge when idling at stoplights (engine set to ~550RPM in drive when idling) I know there are other things going on inside the engine. I was kinda leaning toward a newer long block so that I could rebuild it in my free time and when a weekend allowed I could swap the whole unit (engine/heads).

The other problem is that I have been driving it as my daily driver for the last couple months and rely on it for transport to and from work these days.
 

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Coupla questions...

How do you know the valves are sinking? Describe any performance issues you may currently be having....

What kind of shape is the rest of the engine in?

How many miles on the engine?

The 400.00 bill from the second shop sounds about right.....you might be dollars ahead in the long run to save up, build the 302 and install it, depending on the operational condition of the 289.

Get back with some more details if available....
 
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Discussion Starter #7
Currently the motor runs great, but as I have been driving it, the motor seems to idle more erratic every week. Why do I think a valve (or 2) is sinking? When up in ND last week, I stopped by to chat with my second cousin he works for an engine rebuilder (Dakota Engine Rebuiders, in Jamestown ND) he build all sorts of engines from stockers to alcohal burners for the Wissota racers. I caught him on his day off at home so we had lots of time to play with things like timing and A/F mixture. When all was said and done we had moved my vacuum advance from the straight vacuum manifold port to a ported one. The engine really loaded up (rich) when idling and max timing. It ran great on the highway when accelerating and just cruising along (before and after vacuum port switch) but there is just an unmistakable miss when idling.

The tests which I haven't run yet to make sure are to pull the valve covers and look for one valve stem to be higher then the other, which seems to me like it requires the rockers to be pulled and a straight edge to be put across all the stems. And the other one is a compression test which I was told might tell me nothing, even if a valve is sinking because the valve is still sealing the chamber (and my compression gauge requires you to hold it in place while somebody cranks it, and I haven't had time to round up a buddy since I got home Sunday).

It is only 850 miles from my house to Jamestown ND but I somehow managed to put on 2200 miles for the week long trip. It used 2.5qts of oil (total for trip) and ran 16mpg on the way up and 17mpg on the way back. When I was there I also swapped out the points for a Duraspark dist with a GM ignition module (all free) new dist cap, rotor, and plug wires, new plugs 1 week before the trip, I also hooked up the PVC hose to the bottom of the carb instead of the 10" edelbrock air cleaner assembly, which I pulled in favor of a massive 15" plain jane (no name) chrome with K&N in it. The carb and intake are new as of last August. The carb is an edelbrock 1406 (600cfm electric choke) and has been rejetted about 6% lean from base and it still seems to run rich. The rear main seal is leaking and needs replacing.

That last question is funny to me "how many miles in are on the engine?" odometer reads 39,248 anybody wanna guess how many times that has turned over? When I had the car repainted it was atleast the second time that car has had major body work (one quarter panel had already been replaced) Somebody abused this car prior to my purchasing it, honestly I *should* go pull the numbers from the engine to make find out if it really is the original motor.

You want details, I'll give you details
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Ok, so you now have the PCV running off intake vacuum at the carb throttle body base and the ignition vacuum advance running of the ported vacuum on the carb...

IME, that's how it should have been all along..*G*

But, those changes would have a marked effect on both the A/F ratio at idle as well as effective timing so this may account for some of your idling problems. A systematic re-adjustment of idling parameters (mixture, speed and timing) may be in order.

You also noted oil consumption...while not excessive for a vintage engine, it is a bit more than normal...have you examined the spark plugs after a good pull under load without extended idling to get a reading of chamber conditions? The effect of oil consumption (if being burned) can have a detrimental effect on idle quality due to its effect on the spark plug. You did have leak(s) but didn't mention any symptoms of oil burning.

Perhaps a more interesting test would be a leak-down test, which doesn't require any help and can pinpoint inefficiencies. You can read more about it here

If you have anything further to report, post...good luck!`
 
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Discussion Starter #9
In true form, I read that document and a couple others http://www.mbmopar.com/Hot_Topics/hot_topics.htm (I know it says mopar in the title, nothing I could do about that) And went out and bought everything I think I need to make my own tester. Read all about it http://www.phlegm.us/tech/leakdown/leakdown.html
After the unit was scanned (Camera still in shop) I did add a second Air pressure regulator with gauge. I was going to just add a air pressure gauge, but the regulator was cheaper then any of their gauges (who knew?).

The way I *think* this thing works is to set the pressure with the first gauge, make sure the second one is cranked way out to a setting equal to or higher then the first one. I was going to set the first one at 100lbs and check the resulting holding pressure in the second one. Then divide the second number by the first which would tell me what percentage it is holding, then a little subtraction to get percentage of loss per cylinder.

Now that all seemed too easy, what am I missing?
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Now that all seemed too easy, what am I missing?

Hey, got me...*G* I just paid Summit 59.00 back in '95 and bought one...I just read the pressures on the guages and use the included conversion chart...

Engineering is fun but sometimes I'd rather be racing...*G*
 
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Discussion Starter #11
my problems from the beginning has been that I had never heard of a leakdown tester before you mentioned it, and that I do not know anybody who has ever used one nor have I ever seen a real one. But if all else fails, I end up with some good parts that I can use for "normal" air compressor type duties...

Engineering is fun, but trial and error can be a real adventure at times.

ron
 
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