Bent Pushrod, Idle Miss

[Poser]

Dave, you should source a nice '74 F-n-a-half to rebuild

Trust me, Ed, the thought has never been far from my mind as these things keep happening. ;p

For what it is worth and with all due respect my Doctor friends:


I would have a VERY DIFFICULT time telling anyone wanting to run a gas Toyota six-cylinder engine, to spend good money on an F engine. F/F.5 makes no difference to me. Get a known-good, running, complete 2F engine, install it or build it then install it, and do not look back.


If you were concerned about a 1000-point restoration on a 40 series then common sense is already out the window, so zero timing the novelty 135 or other F engine would be part of the deal.


If I were looking for reliability and longevity out of a gas Toyota six-cylinder engine, and planning on driving it daily for the next 20 years, the last one that I would spend a penny on would be the F/F.5

 

[IDave]

For what it is worth and with all due respect my Doctor friends:


I would have a VERY DIFFICULT time telling anyone wanting to run a gas Toyota six-cylinder engine, to spend good money on an F engine. F/F.5 makes no difference to me. Get a known-good, running, complete 2F engine, install it or build it then install it, and do not look back.


If you were concerned about a 1000-point restoration on a 40 series then common sense is already out the window, so zero timing the novelty 135 or other F engine would be part of the deal.


If I were looking for reliability and longevity out of a gas Toyota six-cylinder engine, and planning on driving it daily for the next 20 years, the last one that I would spend a penny on would be the F/F.5

It's ALL about the novelty to me, Steve. You are absolutely spot on!

Now, why do I have holes in two different pistons? Does it have anything to do with the Chevy valve spring retainers? And do I have Chevy valve springs?

Or, maybe the fact that the oil pressure regulator gasket was put on backward, half obstructing one of the oil holes.....

 

[fj404life]

For what it is worth and with all due respect my Doctor friends:


I would have a VERY DIFFICULT time telling anyone wanting to run a gas Toyota six-cylinder engine, to spend good money on an F engine. F/F.5 makes no difference to me. Get a known-good, running, complete 2F engine, install it or build it then install it, and do not look back.


If you were concerned about a 1000-point restoration on a 40 series then common sense is already out the window, so zero timing the novelty 135 or other F engine would be part of the deal.


If I were looking for reliability and longevity out of a gas Toyota six-cylinder engine, and planning on driving it daily for the next 20 years, the last one that I would spend a penny on would be the F/F.5

Please explain. I know they have a "better" oiling system. But really they seem to be a real realiable motor? Mine is still going after 40 years...knocks on wood.

 

[Degnol]

For what it is worth and with all due respect my Doctor friends:


I would have a VERY DIFFICULT time telling anyone wanting to run a gas Toyota six-cylinder engine, to spend good money on an F engine. F/F.5 makes no difference to me. Get a known-good, running, complete 2F engine, install it or build it then install it, and do not look back.


If you were concerned about a 1000-point restoration on a 40 series then common sense is already out the window, so zero timing the novelty 135 or other F engine would be part of the deal.


If I were looking for reliability and longevity out of a gas Toyota six-cylinder engine, and planning on driving it daily for the next 20 years, the last one that I would spend a penny on would be the F/F.5

Is there an essential difference, other than displacement, between the F1.5 and the 2F? After all, he has that "in hand"............
I'm not disagreeing just asking...really.

Your kinda-doctor friend

 

[Poser]

Now, why do I have holes in two different pistons? Does it have anything to do with the Chevy valve spring retainers? And do I have Chevy valve springs?

You ever been into this engine other than now?

So does that hole go all the way past the four ring sets and out into the crankcase?



It is not unheard of machine shops installing Chevrolet valves/keepers etc. when going through a head, because everything is the same as the Chevy 6, remember? They sure look like old Chevy 6 valve keepers/caps, etc.


I had Chevy valves, hardened seats and silicone bonze guides installed into Land Cruiser F cylinder head for a 1971 F engine that I wasted a 55-gallon drum of money on building back in 1988.

Or, maybe the fact that the oil pressure regulator gasket was put on backward, half obstructing one of the oil holes.....

The gasket causing an oil flow obstruction did not do anything for longevity of component life, but I have a hard time blaming it for what you have going on here. The top end of the engine is wet. It has seen oil. If it were dry and covered in a metallic powder, then, I would think that the lack of lubrication could be creating drama.

 

[IDave]

You ever been into this engine other than now?

So does that hole go all the way past the four ring sets and out into the crankcase?

It is not unheard of machine shops installing Chevrolet valves/keepers etc. when going through a head, because everything is the same as the Chevy 6, remember? They sure look like old Chevy 6 valve keepers/caps, etc.

I had Chevy valves, hardened seats and silicone bonze guides installed into Land Cruiser F cylinder head for a 1971 F engine that I wasted a 55-gallon drum of money on building back in 1988.

The gasket causing an oil flow obstruction did not do anything for longevity of component life, but I have a hard time blaming it for what you have going on here. The top end of the engine is wet. It has seen oil. If it were dry and covered in a metallic powder, then, I would think that the lack of lubrication could be creating drama.

All I've done with this truck's engine is replace the manifold gaskets and the two leaking freeze plugs underneath the manifold 3 or 4 years ago after I got it.

That, and adjusted the valve lash.

The motor is now dangling from a hoist so we can pull the bellhousing and mount it on a stand. Then, we'll see what other surprises are hiding in there for us to deal with. Maybe those are Chevy pistons in there, and they don't fit so well. Maybe that's why the top compression rings broke, if that's what happened.

The oil pressure (according to the factory gauge) did always look ok to me.

 

[Poser]

Primarily, parts availability but more power, stronger construction, and better lubrication design does not hurt either.


Just because you can find something for your 40-year-old engine today, does not mean you will easily locate or procure the part ten years from now when it decides lay down and cause you drama.


You do not have to shim main caps on the 2F.

 

[Degnol]

Primarily, parts availability but more power, stronger construction, and better lubrication design does not hurt either.


Just because you can find something for your 40-year-old engine today, does not mean you will easily locate or procure the part ten years from now when it decides lay down and cause you drama.


You do not have to shim main caps on the 2F.

I thought the oiling system was the same as a 2F? "Parts availability?" what is different from the 2F with the exception of pistons/rings? Not that those aren't important.....but who is to say that those same parts will be available in ten years for a 2F?
Just trying to spar wit' you

 

[Trollhole]

Anyone notice all the blocked coolant holes in the back? It would be suffice to say you cooked the ass of your motor melting your pistons. The PO probably spent the money on paint vs getting a couple gallons of coolant. Caked rust makes a great insulator. The reason your freeze plug fell out was probably the rust ate it from the back side. A good sign that you need your engine flushed is when you drain the motor and you open the rear drain plug and nothing comes out.

Time to seriously consider replacing that motor. It's be seriously neglected.

Your pistons are beat to hell. I'd trash the whole damn thing.

 

[IDave]

Anyone notice all the blocked coolant holes in the back? ...

I see what you're referring to, and it's what I was afraid we'd find. I need to look more closely at that today.

When I changed the freeze plugs I flushed the engine and although the block drain was plugged then, I opened it easily with a little screwdriver. The same happened when we opened the drain yesterday. There was less than a teaspoon of rust plugging the block drain, and the coolant otherwise came out fast, clean and pretty.

When the water jacket sludge killed my F145 engine, it was the head gasket that blew in the back. As far as I could tell yesterday, the head gasket was fine on this engine.

I'll poke at those holes.

 

[Coolerman]

What's the plan again for this motor?

I like messing with the old stuff too, but I think I would take theis motor to a machine shop to be disassembled, dipped, then rebuilt.

 

[IDave]

Right now the motor is in the shop of a professional mechanic who has worked on Toyotas for as long as I've been working on people and who is honest and smart. We're pulling it apart and we'll see what's what and decide whether it's fixable or not.

I would LIKE to make it go if I can do so.

 

[IDave]

So, I don't know what we were seeing in yesterday's picture, but there was no rust plugging those rear water jacket holes when we looked this morning. Perhaps it was rust floating on the not yet emptied coolant. Or just an optical illusion.

There was nothing plugging the head, either.

I did find some sludge, but I had to dig pretty deep to find it. Certainly most of the cylinder where the rings were riding had coolant surrounding it.

 

[IDave]

You can see where the #6 piston had been chewed into by the broken top compression ring before it blew through the top edge.


The same happened to the #5 piston.

That piece of ring was all that was left of the top compression ring on #6.

 

[IDave]

In fact, all 6 pistons had broken top compression rings. But none of the cylinders are scored!

I guess I know now why my compression numbers were so low (100 to 118) even in 2006, which is the first year I have records. I had always assumed its rings were worn, although I didn't understand why adding oil didn't make a difference.

Guess I know now.

It's apparent that the engine was rebuilt not so many miles ago. The bearings aren't in too bad of shape, but the crank journals, especially the rod journals, are scored enough that the crank will have to be reground, if we go that route, which depends on whether we can find all of the parts we need, like a set of oversized pistons.

Still not sure what caused the ring demolition for all 6 pistons. Perhaps poor assembly previously (which would go with the funny stuff I found on the head) or a bad case of severe backfire, which I won't swear I didn't do, but I don't recall.

 

[Coolerman]

I seem to recall Jeff Zepps rebuild on his old F engine having the same issue with broken rings..

Yep I found this pic....

 

[Trollhole]

There was also another thread about broken rings. The idea being an overheating issue that is allowed to cycle between really hot and then cool down then back up to hot again over and over would do this.

I'd still be looking for a 2f to rebuild. One that hasn't been cooked.

Honestly just think about it. Your gonna have to have it rebuilt all the way. Your head is a mess. Your block has had lot of rust in it for who knows how long. You have had metal bits floating around in your oil for who knows how long.

I really think you need to punt and find a better canidate. I'm sure you could rebuild your F you have now. But considering all that is wrong with it. Wouldn't it be money better spent on something better? Plus I'd be ticked if you were on the trail with me and you had engine problems knowing you didn't at least explore other options.

 

[IDave]

There was also another thread about broken rings. The idea being an overheating issue that is allowed to cycle between really hot and then cool down then back up to hot again over and over would do this.

I'd still be looking for a 2f to rebuild. One that hasn't been cooked.

Honestly just think about it. Your gonna have to have it rebuilt all the way. Your head is a mess. Your block has had lot of rust in it for who knows how long. You have had metal bits floating around in your oil for who knows how long.

I really think you need to punt and find a better canidate. I'm sure you could rebuild your F you have now. But considering all that is wrong with it. Wouldn't it be money better spent on something better? Plus I'd be ticked if you were on the trail with me and you had engine problems knowing you didn't at least explore other options.

You are right. This engine isn't that trustworthy, it will be expensive and a pain, but switching over the column shift, clutch setup, new carb, linkage, bla bla bla, etc won't be cheap, either.

However, this truck is not intended to be a wheeler. I doubt I'll ever take it on any tough trails: that's what the FJ40 is for!

 

[IDave]

Well, the mechanic I'm working with talked to an engine builder he works with this morning (apparently this guy's been doing 2-3 Fs or 2Fs per month, all years, lately. They've been coming out of the woodwork in Idaho!). His feeling is that the ring fracture like that is most often the result of predetonition.

 

[Trollhole]

Wasn't talking about all the bit's and piece that bolt to the block. Just between the pan and valve cover. But now that I realize it's a 64 well that's a whole different monster.