Projects Chevy 235 Inline 6 advice

Looks like #3 is having similar issues also. Same place.

 

this?



It looks to me like some carbon got knocked off. It could be a crack....but I wouldn't jump to that conclusion, without a bunch more evidence..

 

OK
#5 is out. I don't know what it should look like. And I didn't really want to pull #4 also to see a good one. Here's what it looks like.

 

Yep that what i was taking about. Regardless, i wouldnt put $450 into that head cracked, or not. I think its a crack but pics are misleading at times.

 

Do the rings move on the piston or are they stuck? The truth of the matter is that more detailed checks should of occurred b4 a total teardown.. Oil test didnt help much. Suspect issue would put you in the head. You pulled the piston, why? Leak down test would of revealed more. Honestly.

 

Get a pic tool and a magnifying glass. Check the head in the suspect area rigorously. Clean the area with carb or brake cleaner. The crack wont disappear if its real. Youll either find a crack or not. Update us with the findings.

 

I have been reading this Urban Legend for about 20 years. It has been discussed ad nauseam on the Stovebolt Forums and no one has ever presented anything other than rumors. I’d be interested in seeing some reports that support that idea.

 

Ditto. Id like to know the truth also.

 

the rings look tired
the $450 on the head rebuild sounds high
if the valves feel good, get some valve grinding compound and clean up the seats
re-hone and re-ring
old school overhaul

 

same here
GM had a plant in Japan before the war started and supposedly there was a gm plant somewhen in the Philippians
there was supposed to be a hemming's article about this but I couldn't find it

 

I'll check it in the morning.
If it's cracked is it toast?

 

Anything can be fixed. If thats cracked, it wont be worth it. So...yep. toast. But check, dont guess.

 

My overhauled cylinder head was just over $400. This included new guides, hardened exhaust seats, upgraded stem seals and manga flux. Valve springs were also replaced.

 

The rings are stuck. You can free them up, and it will probably get some compression back, but if you take out all the pistons, hone the block, and put in new rings, it will get all of it's compression back. And last several tens of thousands of miles....the number depending mainly on how much taper is in the bores.

If you want it perfect, of course you'll have to get it bored, new pistons, then you'll want t get the crank ground, new bearings, a reground cam and lifters, valve job including guides and seats and replacing the springs, and most of the valves because they have a tad over .001" wear on the stems...it never ends, till you get up to about $3-4k.

 

You are right.
The rings are frozen. That would explain the scoring in the cylinder wall.
I see Ebay has Hasting piston rings for $42. Is there a better way to go?

https://www.ebay.com/i/254075589702...1291&msclkid=730becd29a78122cc705b35746ff5ccf
I took another picture of the underside of the head. All of the valves look black except #5 which is brown.
I'm still mulling over what to do with the head.

 

This is the #5 piston top.
.040 over I guess.

 

Ask "mike" was a running joke at work.

 

3.5625+.04=3.6025
Mic says 3.600"
Calipers account for the +- .002. No bore Mic in my budget garage.

 

I get rings from ebay for old engines like this....sometimes you can find the size you need, NORS, for $20...

Yup, it's .040 over

 

For starters.......I LOVE the swap of the Chev 235 into that era Willys truck........also.....nice winch. I have rebuilt lots and lots of those motors. Keep it simple......make sure you have no cracks in head......these engines are very easy to just do a simple lower end rebuild with inexpensive parts. Once again......verifying no cracks in head is the biggest issue. If you have not done engine rebuilding before.......this is probably in my opinion the easiest and most forgiving engine there is. Basics......basics.......and results are NOT predicated by $$$$$$$$ spent. Have fun.

 

I can tell you for sure that a 235 and Toy head look very much alike. But they are enough different that they don't interchange
It's been tried, unsuccessfully.
The very first Toy that I did engine work was a Corona 4cyl. Owner's wife had gotten it hot and detempered the rings. Dealer want a bunch to fix. I put in rings and bearings, did the valves. When I pulled the valve cover it looked just like a 235 less two cylinders. Clearly a copy, but not exact as bolt spacing was just a little different, not enough to see with the naked eye.

 

yes, the ToyoPet engines are different. They look very similar, though.

 

I would try lapping the valves. Nothing to lose but time. Could gain a LOT

Ben

 

Thanks Tractorguy. I'm looking forward to driving it. I've attached a couple of pictures of the underside of the head after I've cleaned it. I could not find any cracks, but, the obvious pitting on the valve from sitting is water is concerning. I hope that the pitting was possibly the result of a previously blown head gasket that was left sitting for years. Although the head gasket I removed looked to be in good shape. But the .040 over rings on #5 were frozen.? Strange.

 

I don't want to spend a lot of $ so next week when the rings arrive I'm going to install them and mount the un-cracked (I hope) head. I removed the head without changing any of the valve settings. Should I loosen all the adjustment screws and start over or is there another way? I found this procedure at Stovebolt.

To adjust lifters on a 216, 235 or 261, here is the correct procedure.
First- Your valves are laid out this way- from front to back:
#1 exhaust
#1 intake
#2 intake
#2 exhaust
#3 exhaust
#3 intake
#4 intake
#4 exhaust
#5 exhaust
#5 intake
#6 intake
#6 exhaust

This procedure can be used on either Hydraulic or Solid lifters. Just know which kind of lifters you have* for final adjustment.

Turn the crank (by hand) until #2 cylinder intake valve (look above- it is the third rocker back from front) is observed to start opening (that means the rocker is pushing the valve down and open). Now turn the engine slowly and notice that #1 cylinder exhaust (first rocker)valve will also start to open. Continue cranking until #2 cylinder's intake valve is wide open, AND then notice that #1 exhaust valve is also coming to the wide open position. (#1 exhaust valve lags a little behind #2 intake valve) Continue turning (slowly) until both valves are wide open.

With these two valves wide open adjust: Solids: intake-.006. exhaust-..013 (special note: if this is 1 1/2-2 ton truck exhaust is .020) Hydraulics: adjust until just touching and no or very little wiggle of rocker can be felt. Adjust: #1 cylinder intake #2 " exhaust #3 " both #5 " intake #6 " exhaust.

Now turn the crankshaft one full turn until #5 cylinder intake is observed to start open. Lagging behind will be #6 cylinder exhaust. Continue turning the crank until both of these valves are wide open and then adjust: #1 cylinder exhaust #2 " intake #4 " both #5 " exhaust #6 " intake.

Your engine will now be ready to start. Let it idle for 30 minutes till completely warm and do the final adjustment.

It has been brought to my attention that I didn't give the final adjust for hydraulics -- Tighten down until no noise is heard (use a section of hose to your ear and to the tappet if needed) then tighten one(1) complete turn.

* If you don't know whether you have solids or hydraulics -- Pull the rocker cover, loosen one rocker, pull the push rod, drop the side cover off, pull that lifter. Now take it to a machinist or mechanic and ask him which it is. OR, once you have the lifter in hand look to see if it has a hole in the cup (top) end and will push down in the center, if it does, it is hydraulic, if not it is solid.

 

I also bought a leak down tester to check it after I reassemble.

 

you can leave the valve adjustment as is, and set them after you put it all back together. Or loosen them all now, whatever you want. If you leave them, then you will be compressing some of the valve springs when you install the rocker shaft assembly.

 

I'd pull that one valve and look it and the seat over while it's apart.

 

I have a 64 FJ40 and the engine looks like a 235 but it is a little larger than the Chevy the head is a little over an Inch longer and a little wider. The bellhousing pattern is the same. I am told the thermostat housing will interchange but nothing else. The later FJs use a 12 port head its to bad it won't fit the Chevy

 

When the engine was setting some of the valves would not have been on the seat so if the air cleaner was off or got wet moisture could have gotten into the cylinder through an open valve. If there was standing moisture you would have seen more evidence but in places with high humidity and changing temperatures over time moist air can get in and cause rust. The discolored area at the top of #5 cylinder could be from the piston sitting partly down the bore with a valve open. That valve seat is likely as pitted as the valve, the valve is harder than the seat. I'd at least check that seat and any others that show signs. I've run several of these and GMCs that sat for years. (great truck engines!) As long as it is this far apart check the bearings too, at least the rods. At this point if it were mine I'd hone the cylinders and do new rings, check the bearings even the mains (plastagauge), lap all of the valves and install new seals. Check the guides. BEST gasket Company makes the best set for these engines and their rear main seal is unbeatable. Change it too while you are there and the front seal. As you know by now you have to pull the pan before you can remove the timing cover because for some reason two bolts come from the inside. I don't remember for sure if it 5/16 or 3/8 but you can tap the hole with no drilling and then put those larger bolts in from the outside, just in case you ever need in there.