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Discussion Starter #1
Ok solved my oil pressure problem and now on to other problems

Im not exactly sure where to start but the engine runs hot, 210-220

the engine runs ok, although I can't get what I would call good vacuum, once the heat has soaked into the motor I get a very audible whine or vacuum leak from the carb, although spraying carb cleaner all around intake and carb base has now effect on idle quality

currently

vacuum is anywhere from 13-16, but when readings are taken Id say the number solid, drifts an +-1inch or so maybe

temp is 210-220

timing 8 initial with manifold vacuum advance

One observation is that I don't seem to be getting a lot of coolant flow, at temp shouldn't I be seeing coolant hauling *** in the radiator? which direction? Water pump is new, thermostat is new, tested before it went in

Another observation is that when cam and crank gears aligned timing mark is about 8-9 degrees advaned of the factory location. timing has been done with factory mark

running stock exhaust, holley 390 on a offenhauser intake manifold, holley is mounted so primaries are away from the engine

arndog
 

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temp is 210-220

timing 8 initial with manifold vacuum advance
WRONG!!!!!!!!!!!!!!!!!!!!

Disconnect the vacuum advance when setting timing. Also with today's poor fuels the engine will need more timing. Maybe 12-14 initial WITHOUT THE VACUUM ADVANCE HOOKED UP!

Al
 

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Discussion Starter #3
sorry Al what I meant to say by that is my initial is 8 and then I hooked up manifold vacuum advance giving me about 22 degrees advance at idle

arndog
 

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Discussion Starter #5
anybody have a vacuum reading on a stock-ish 250, looking for a ballpark / baseline

arndog
 

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You might try another t stat, maybe a 180* and see if anything changes.
I have seen my share of brand new ones not working properly. If no change
the radiator could be clogged?
 

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i was going to say the same thing.. check the radiator... often overlooked...

and if you have ac.. check the grime between the condenser and radiator.. that will drop temps considerably once the crap is out of there...

I had a customer complaining of bad smells and overheating once... everyone told him it was his heater core..etc...

I took a look and he had a dead, cooked, squirrel between his rad and condenser... no joke!

And I had to charge him to remove all that...nasty... he didnt care his issue was solved!
 

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Discussion Starter #9
new radiator and new heater core, new water pump, ill mess with thermostat again although im pretty sure I tested it before putting it in as I learned the hard way on that one

arndog
 

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Idle vacuum on my 1973 250 is 19 at idle in neutral. It's a manual. Light throttle cruise on level ground I see 20. This engine is stock other than Offenhauser intake, 390 Holley 4bbl and split cast headers. 2.25" exhaust and turbo muffler.

My engine temp is typically 190°F but I have seen 200°F under load on a hot day. Temp sender is in thermostat housing. Also 180° thermostat.
 

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Discussion Starter #12
manifold gasket question

hopefully found my vacuum problem, Id say 10 of the 12 ports showed leaking on the gasket, but of course I have another question

my intake/exhaust manifold gasket has two surfaces, 1 is smooth and the other like a perforated metal, what side is supposed to go against what?

arndog
 

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hopefully found my vacuum problem, Id say 10 of the 12 ports showed leaking on the gasket, but of course I have another question

my intake/exhaust manifold gasket has two surfaces, 1 is smooth and the other like a perforated metal, what side is supposed to go against what?

arndog
Perforated metal side to the exhaust manifold.
 

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Are your manifolds totally flat on the sealing surface? I'm running high-temp RTV on my stock exhaust manifolds (350 v8) without gaskets. I had an issue with exhaust leaks running a gasket. I had my exhaust guy level the manifolds on a big belt sander, RTV with no gaskets and no more leaks.
 

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Discussion Starter #15
dang it I thought I messed it up

surfaces were screwed, Im changing a lot with this fix, although I might test just flipping the gasket

couple problems with my config, stock exhaust manifold, offy intake, two different metals expanding at different rates

when I bolted together the surfaces were not very lined up

I have the cast iron headers just wanted to get running with the exhaust I had, Im going to go with the cast iron headers this time and install the gasket correctly, I think this will solve my problems

arndog
 

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Wow, Reading all your threads sounds like my story. From the clifford cam eating the bearings causing low oil pressure, to the running hot. I am beating my head against the wall. Have you found your problem?
 

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Discussion Starter #17
Not yet, working on exhaust to hopefully solve vacuum problem, then onto valve timing

What's your config and symptoms?
 

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Also drop that "new" thermostat in some boiling water to confirm it opens all of the way. I bought several new 180 and 190 t-stats that did not fully open or took forever to open. You get what you pay for and the universal replacements from the local parts store are garbage most of the time.
 

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Discussion Starter #19
Yeah, I might even go as far as buying one of those coolview things so I can see the stupid thing open

arndog
 

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Where does the builder sit?

Arndog, sorry to hear you still are chasing after this. The 250 has been one of the most reliable engines built ever.

So lemme ask you...Where does your "builder" sit with these problems today?
 
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