Got the motor out....

68Flareside240

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Well only took a few months but I finally parked the truck and got the motor out. Disassembly was pretty much uneventful, once I had made 37 trips inside to my toolbox. Took me the better part of a day working by myself and labeling and bagging everything. Pistons badly carbon caked, looks like number 4 and number 6 took the brunt of it. Number 4 piston was burned, number 6 not quite as bad. Cylinders look really good to the naked eye. I couldn't find my puller to get the balancer off so haven't got the bottom end apart just yet. More (and better) pics to follow.


 

68Flareside240

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One was wet. Had oil leaking from behind the exhaust valve what I could tell. No idea about four other than maybe losing compression. Deposits everywhere, even visibly holding the intake valve open. Lots more pictures I will post tomorrow. But if anyone can tell me about the rods going from the plugs (literally rods off the plugs) going into the exhaust port on this head I’d love to know. That’s a new one on me. I will also post pictures of that.

The block casting is 8C25. Head is 8C22. Truck date code is late April 68 so makes sense. I’ll get more pics up when I get to the office tomorrow.
 

Mdixon300f100

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Yeah those 4/6 exhaust valves look burnt, did you do a compression test before you pulled the head? Maybe the cam lobes are worn, causing less valve lift, possible not drawing enough a/f mix into those cylinders? I don’t know, but usually 3/4 are the richest on the carbed heads I’ve pulled, with 1/6 looking slightly leaner, but certainly not white exhaust valve lean...
 

Mdixon300f100

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68Flareside240":3ib98eo2 said:
One was wet. Had oil leaking from behind the exhaust valve what I could tell. No idea about four other than maybe losing compression. Deposits everywhere, even visibly holding the intake valve open. Lots more pictures I will post tomorrow. But if anyone can tell me about the rods going from the plugs (literally rods off the plugs) going into the exhaust port on this head I’d love to know. That’s a new one on me. I will also post pictures of that.

The block casting is 8C25. Head is 8C22. Truck date code is late April 68 so makes sense. I’ll get more pics up when I get to the office tomorrow.

The air injection system pumped fresh air into the exhaust ports to help light off the catalytic converter, those rods may be the air tubes, if that’s what your talking about, but you don’t have a picture so again I’m not sure...
 

68Flareside240

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Well, I believe I found the culprit on 4 and 6. The porcelain insulator on the plugs was cracked, leaving visible carbon tracking as the spark leaked out to ground on the head and not through the plug. When I touched the insulator, it fell off.
Here's the plug for 4. 6 was not near as bad.

Head on 4

Piston on 4. I was told one piston was replaced. I assume this is it. The STD give evidence to the notion the block has never been out of the truck.

Cylinder wall on 4

Casting Number of 8C25 makes sense for original motor. Truck was built late April, 1968. Head date code was 8C22.

These are the "rods" coming off of the plugs going into the exhaust port. They're in every port, some eroded worse than others.They are extensions off of the six square headed plugs on the manifold side


Various pictures

 

68Flareside240

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Mdixon300f100":3il4em9l said:
Yeah those 4/6 exhaust valves look burnt, did you do a compression test before you pulled the head? Maybe the cam lobes are worn, causing less valve lift, possible not drawing enough a/f mix into those cylinders? I don’t know, but usually 3/4 are the richest on the carbed heads I’ve pulled, with 1/6 looking slightly leaner, but certainly not white exhaust valve lean...

Compression was down across the board. I was initially a little taken aback as I figured 3 and 4 would be the most rich due to position of the carb, but think I figured out the cause as stated.
 

pmuller9

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It looks like you have the RARE heavy duty timing gear set.
How many teeth are on the crank and cam gear?

You also have the good connecting rods that do not have the oil spit hole in the big end.
This engine is a good candidate to make a street screamer.

The tubes in the ports were from the smog pump.
You can get plugs for the holes once the tubes are removed.
 

68Flareside240

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I am not sure about the timing gear. I was wondering about it as it did not appear to be phenolic. Here is a better picture of the gear set.
Sorry its upside down.

Edit : the 2752 appears to be an obsolete Sealed Power number, assume it was replaced when the rest of the work was done.
 

68Flareside240

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I have a date tomorrow morning with a machine shop. I think I called 5 shops before I found someone who was interested in talking to me about my project before saying "we don't do that" , "race engines only" etc. Taking it all over tomorrow to check out and mic and talk about what I want out of it.

My goal for this motor is to build a good street motor. No towing to speak of (12' jon boat), just driving. My plan so far (please feel free to give me any advice) is to keep bottom end stock (new bearings & pistons), get the head worked and the other rocker studs tapped, and keeping the chevy rockers. Intake will most likely be a Offy C with a small 4V or 2V, and headers. My question is cam. There is a ton of info and cams out there and I am having a hard time wrapping my head around it all and how it fits what I want to do. I guess what I want is mild performance to match intake and exhaust, but not run into issues using the chevy rockers (I am willing to go back to stock if necessary) and having to change too terribly much with valvetrain. If I am going to need to do things like stiffer springs etc, I want to know to do it from the start and not have to backtrack too much. There is really no rush on getting it built, as there is a lot I need to do to the truck before I am ready to replace the motor. Thanks for all the help, the more I learn about these engines the more questions I have.
 

THE FRENCHTOWN FLYER

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Judging by the looks of the crosshatch pattern it looks like somebody re-ringed it and used a dingle-berry ball hone. The pattern does not look factory.

Fine tooth metal gears were used for a number of years in production and should be still available; a good upgrade from phenolic and anything that uses a knock sensor.

I'll let pmuller recommend a cam brand. I'd go with something in the 280* / .500" lift range with 1.94 intake valves.
 

68Flareside240

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Yes the motor had a ring job when the head was worked. Based on the assumption the block never came out, I would assume the dingle berry hone (never heard that term but like it) was used. Will be pulling the pistons and crank tonight, more pictures on the way.
 

68Flareside240

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Had minor health emergency last night, so couldn’t get the motor apart until this morning. Rod bearings were all good except for 4 and 6. They were wiped pretty good down to the copper in a few locales. I’ve got a pretty idea as to why.... but I’ll see if someone can guess it first(Hint:motor was reringed in the truck by someone who probably didn’t know what they were doing). Main journals were all pristine, slight wear on the the thrust bearing surface but other than that they were great. Crank and all looked really good as well. Try to get some pictures up when I can.
 

pmuller9

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The rods should have C5AE on the lower part of the beam.
Those rods used the Ford 289/302 V8 pistons.
 

68Flareside240

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Pmuller I could be wrong but I’m 99% sure they were C6AE. All pistons were 4valve relieved as seen. I know the later ones have more limited piston choice. Are there any pistons I should look at or just go back with stock 289/302?
 

pmuller9

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68Flareside240":3sjl7bat said:
Are there any pistons I should look at or just go back with stock 289/302?
Use a Hypereutectic aluminum piston.
Measure the block deck height after it has had a cleanup cut taken off of it so you can determine the piston pin compression height.
Pistons come in several pin heights from 1.585" to 1.608".
 

bubba22349

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68Flareside240 said:
Well, I believe I found the culprit on 4 and 6. The porcelain insulator on the plugs was cracked, leaving visible carbon tracking as the spark leaked out to ground on the head and not through the plug. When I touched the insulator, it fell off.
Here's the plug for 4. 6 was not near as bad.

Head on 4



:hmmm: To late but with a set of fresh spark plugs it would have probably still run fairly good! That is really excellent that it's still a standard bore this should be a great block to rebuild. :nod: (y)
 

68Flareside240

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That’s the thing, this motor ran smooth as silk, other than ring issues, which I now assume to be due to a very poor ring job. The head job didn’t help a bit either. But it ran great. I’ve got a strong feeling I’m going to be blown away when I finish this truck. It’s been a hell of a ride so far.

Had a great conversation with the machinist at the shop....... he glowed over the 240 he had in a 70 f100. I think I found the right machine shop despite my best efforts.
 

Max_Effort

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68Flareside240":3ozv7mqv said:
I have a date tomorrow morning with a machine shop. I think I called 5 shops before I found someone who was interested in talking to me about my project before saying "we don't do that" , "race engines only" etc. Taking it all over tomorrow to check out and mic and talk about what I want out of it.

My goal for this motor is to build a good street motor. No towing to speak of (12' jon boat), just driving. My plan so far (please feel free to give me any advice) is to keep bottom end stock (new bearings & pistons), get the head worked and the other rocker studs tapped, and keeping the chevy rockers. Intake will most likely be a Offy C with a small 4V or 2V, and headers. My question is cam. There is a ton of info and cams out there and I am having a hard time wrapping my head around it all and how it fits what I want to do. I guess what I want is mild performance to match intake and exhaust, but not run into issues using the chevy rockers (I am willing to go back to stock if necessary) and having to change too terribly much with valvetrain. If I am going to need to do things like stiffer springs etc, I want to know to do it from the start and not have to backtrack too much. There is really no rush on getting it built, as there is a lot I need to do to the truck before I am ready to replace the motor. Thanks for all the help, the more I learn about these engines the more questions I have.

The biggest improvement and "bang for the buck"
Is going to be a 300 rotating assembly (crank, rods and pistons), in your vintage block. 60 cubes is a big increase.
 
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