High mileage refresh and head re-build: advice needed!

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HemiAlex

HemiAlex

Long live the 2F
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So I've got a dead #5 with 25psi. It explains my stumble and misfire. When I get time, I'm going to pull the head. We're planning on a full set of intake and exhaust valves, seals, springs, a surface and a good 3 angle valve job. I'll use an OEM gasket. It seems that a .020 mill is popular for a compression bump. Do you adjust for this with pushrods or valve adjustment?

I'd like to formulate a plan of all the possible things that I should replace while its apart. It's got 278k on it and I'd like to prepare it to completely wear the shortblock out. All the other holes are around 150 psi, so it's got plenty of life left in it.

-My intake and exhaust manifolds are already planed for straightness. I might sneak a header in for a small power boost.

-The shortblock has great oil pressure. I don't see a need to do much down there aside from maybe pull the pan, clean it nicely and re-seal it. Should I replace the oil pump while I'm there?

-Should I replace the timing set with another Aisin set? Timing is accurate still.

-I've got plugs, wires, cap, rotor and a carb diaphragm waiting. What else can I do for a "tune up"?

-I'll have the radiator cleaned and recored. No reason not to.. I wouldn't mind the champion radiator, I've got one in my 68 Hemi 6.1 roadrunner and I really like it. I would like do do water pump, hoses, thermostat and housing.

Basically everything that is a consumable or wear item in the engine bay will be replaced. Any thoughts or help is appreciated.





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Check your head. I had the same plans after a 0 psi cylinder, found a broken exhaust valve and cracks in the head. Ended up sourcing another one, cleaning it up, taking .035" off, replacing all exhaust valves, cutting seats and installing new valve seals.
 
If your going to drop the pan, go ahead and remove the pistons, hone the cylinders and replace the rings and connecting rod bearings. New oil pump would be good. You may not need to replace all of the valves, just any bad ones. The machine shop should be able to reface them as well as the valve seats. Replace the valve guides. .020 to .030 shaved off the head. The adjusters on the rocker arms will compensate for that when you adjust the lash. The valve springs can be checked for height and strength by the machine shop too. You may want to magnaflux the head to check for cracks. Good luck!
 
I h8headers...and aftermarket oil pumps and timing gears. but I am running an AM oil pump and timing gears on my 862f in my 77 fj55...it uses 3FE exhaust manifolds and a modified intake to match...the big thing I want to warn people of, is it is a tractor engine- don't do much to compression unless you're going to follow it with a cam and high test gas...they are not like 350s- keep some meat on the head. now IF your guides are worn, the fix is 1.50 and 1.84" STAINLESS valves for SBC chevy- the STOCK seats in the head are superior to anything the machinist will use, so don't let hime swap those out- they just need to be opened up to fit the new bigger valves- the guides don't need replaced either, just opened up to fit the larger valves(making sense?) and use stainless and a matched set of basic springs and retainers.....my monster 2F is awesome and runs a 260* cam- next engine I build will have the chevy valves but stock grind cam...and maybe some unshrouding to keep the CCs large and even...HTH
 
my AM oil pump works but had to be honed out to fit the drive shaft...the stock oil pump can have the gears flipped, measure the gap and be used for 30 more years- and don't forget to have the oil galley plug on the head properly PLUGGED...
 
do NOT loosen the oil pump to block mounting boss from the block....
 
Are you trying to build a hot rod or a good stock cruiser motor? Stick with the stock Toyota valve train and replace the valve guides, or at the very least have them resized, IMHO.

Good idea on flipping the gears on the oil pump. The old pump is probably fine, just check clearances when you have it apart.
 
daytonadogie said:
Are you trying to build a hot rod or a good stock cruiser motor? Stick with the stock Toyota valve train and replace the valve guides, or at the very least have them resized, IMHO.
Click to expand...


....I'd defer to JimC on this one...if the guides are worn, fix with chevy valves...but the choice is yours. best to use search and dive into the threads How NOT to build a 2F and The Best 2F...buy some beers and get to reading...all of the answers are already here- somewhere.
 
just, don't, loosen the oil pump mounting boss from the block...TRUST ME
 
I don't want to get into hotrod stuff. I just want to keep it on the road and use as many Oem parts as possible.


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don't mill for compression if you're not trying to hotrod; the new guides pressed in by the machine shop will not be OEM unless you provide them. anyway, here's the water, do with it what you will...
 
I trust in their parts choices and I can bring what I want. The machine work will be done with me present, I apprenticed in a cylinder head shop many years ago.


Sent from my iPhone
 
Are you sure that the head is causing your low compression condition? With nearly 280k miles I'd wonder if your rings need to be replaced.

Repeat the compression test but drop a couple of ounces tablespoons of oil in the combustion chamber (through the spark plug hole) before testing the dead cylinder again. If your compression numbers go up, you've got bad rings and rebuilding the head won't do anything.
 
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I heard and felt it leak out of the exhaust pipe. Warm pressure is unmistakeable.

There were no results from the oil cap or dipstick tube. We narrowed down the misfire by pulling wires, I then pulled the plug and it was crusty and burnt. We moved to a compression test, got 25 psi when the rest of the cylinders were 150 average.
 
GLTHFJ60 said:
Are you sure that the head is causing your low compression condition? With nearly 280k miles I'd wonder if your rings need to be replaced.

Repeat the compression test but drop a couple of ounces of oil in the combustion chamber (through the spark plug hole) before testing the dead cylinder again. If your compression numbers go up, you've got bad rings and rebuilding the head won't do anything.
Click to expand...

A couple ounces?! You could quickly be in for more than new rings if you do that...
 
couple of ounces of oil in the combustion chamber

Too much, IMO.

Years ago, I filled an old pump oil can with ATF. It puts out about 1 teaspoon per trigger pull. I use it for rustproofing doors/fenders, and to easily squirt a consistent amount of oil in cylinder for wet compression testing. 2 teaspoons per cylinder is what I have used. If you let the oil sit for a few minutes, it will run off the piston tops and down onto the rings, which is where you want it to be during the test.
 
Motor has to come apart so what else could it damage? Regardless, I see your point, and the test would work just as well with a couple tablespoons. That cylinder has almost no compression anyway!
 
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