I can't drive 55

[45Dougal]

The head hasn't changed since the PO though, and they didn't have the issue; right?

This is starting to need a spreadsheet.

 

[MatthewMcD]

The head hasn't changed since the PO though, and they didn't have the issue; right?

This is starting to need a spreadsheet.

Correct, this is how it was delivered to me.

 

[Pighead]

This is starting to read like an Agatha Christie story.
An early F with flat top pistons under a 2F head with open chambers should, theoretically, be weak. Perhaps able to accelerate in the lower gears but not in 4th at freeway speeds. Fortunately, I do not trust compression gauges. I've collected at least 4 of them over the years, I don't think any of them are really that accurate.
Did the PO put domed pistons in when he did the head swap? Possibly. I doubt it.

 

[Pighead]

I have only had it road worthy with new suspension for about a month. Before that I was afraid to get it going this fast. So it's probably been like this since I got it.

It's possible that it's been like this since the head swap

 

[45Dougal]

If you really want to measure the head volume, then what? Measure how much Redex you can get into a plug hole at TDC?

 

[pb4ugo]

I wonder if someone has measured the differences in the combustion chamber size in the head between a head for domed pistons and one for flat topped pistons? I would think that info would be archived someplace in this site. A bore scope would be helpful to determine what pistons were installed in the engine. To me the compression are good. If I recall, the po was asked if he was able to achieve speeds higher than the current results, and he said yes. Whether that's accurate or not, idk. I'm inclined to believe him. Matt would know better because he's dealt with him. Higher rpms seem to be achieved in the other gears with maybe less load. B4 cutting the exhaust, let's see how much mechanical advance there is and when it starts and when it's all in. I think it's more likely to be something not related to the head and block assembly, because of past performance. Currently, at wide open throttle(wot) it tops out around 48mph. At WOT vacuum advance is going to have minimal effect because there's no or minimal vacuum present. So mechanical should be about all in. At this point I'm just guessing, because I thought a different carb would have offered better results.

 

[mesa man]

It’s starting to sound like you should just “drive it like you stole it” until you get that other 2F dialed in to drop into the engine bay, unless of course you like going down these rabbit holes and in that case, maybe you should pause for a break and “feed your head!” Cheers!

 

[MatthewMcD]

This is starting to read like an Agatha Christie story.
An early F with flat top pistons under a 2F head with open chambers should, theoretically, be weak. Perhaps able to accelerate in the lower gears but not in 4th at freeway speeds. Fortunately, I do not trust compression gauges. I've collected at least 4 of them over the years, I don't think any of them are really that accurate.
Did the PO put domed pistons in when he did the head swap? Possibly. I doubt it.

No idea, AFAIK, he didn't do any of this work. He got it in working order this way.

 

[MatthewMcD]

It’s starting to sound like you should just “drive it like you stole it” until you get that other 2F dialed in to drop into the engine bay, unless of course you like going down these rabbit holes and in that case, maybe you should pause for a break and “feed your head!” Cheers!

I really want to know what it is. Particularly if it's not the engine.

"I gots ta know!"

 

[Grayscale]

Hmm. Tinkering still, I got an '82 head (came with flat-top pistons from factory) that we can mill-down and install to add some data, and parts to the saga... I never played that Sammy Hagar video, but, I did play the air guitar - needs supercharger, and/or nitrous should be included in your poll. I'm with mesa man on this one. And serious, you can have whatever 2F stuff I have laying around.

Regarding my comments on the lack of a full exhaust-stroke with an early 2F head, consider this, my other rig relies on a carburetor and EGR. The EGR is run off of ported vacuum. It has vac advance, for driving when it is cold, and for EGR. On a carb or TBI, ported vacuum drops-out when the throttle plate is really open. Because extra time is needed to burn cold fuel-mix. or EGR-air-fuel-mix, and you are topping out your rpms at 54 mph., bump-up the static timing by 15 degrees, and/or run vacuum advance from manifold vacuum. If it pings, you can back it off. I understand if you don't want to ruin a good head, and I don't like deviating from the manual, but, you might gain some mph, and mpg. Just my intuition, as this is all uncharted territory.

 

[MatthewMcD]

Hmm. Tinkering still, I got an '82 head (came with flat-top pistons from factory) that we can mill-down and install to add some data, and parts to the saga... I never played that Sammy Hagar video, but, I did play the air guitar - needs supercharger, and/or nitrous should be included in your poll. I'm with mesa man on this one. And serious, you can have whatever 2F stuff I have laying around.

Regarding my comments on the lack of a full exhaust-stroke with an early 2F head, consider this, my other rig relies on a carburetor and EGR. The EGR is run off of ported vacuum. It has vac advance, for driving when it is cold, and for EGR. On a carb or TBI, ported vacuum drops-out when the throttle plate is really open. Because extra time is needed to burn cold fuel-mix. or EGR-air-fuel-mix, and you are topping out your rpms at 54 mph., bump-up the static timing by 15 degrees, and/or run vacuum advance from manifold vacuum. If it pings, you can back it off. I understand if you don't want to ruin a good head, and I don't like deviating from the manual, but, you might gain some mph, and mpg. Just my intuition, as this is all uncharted territory.

I ditched the Weber. Too finicky, too many issues with the other vacuum hoses, back to my Rochester. In the process I managed to dislodge and drop my brake master reservoir lid. It hit the ground in my small garage and totally vanished. I just spent the last 45 minutes looking everywhere for it. I threw a baggie over the top and will look again tomorrow.

Now I am preparing to present a webinar (off camera) in my grease-stained clothes, at least I have wine.

Once I restore the vacuum lines, I'll try advancing the timing and let you know.

 

[chubot]

I originally was guessing at a 4Lo situation but you confirmed RPM so that's out. Still, seems weird that you just lack power in 4th vs the other gears. Brakes aren't dragging, are they?
Hope you figure this out! Maybe go back and review original problems... like the shift linkage. Has got to be a clue.
I applaud your persistence.

I just threw in the low 4 suggestion because I have a buddy with a jeep scrambler that calls me up and says that he put it in gear and nothing was happening. He said no forward or reverse. I said is your transfer case in neutral? All I got was silence in the other end. He just said aww man I can’t believe I did that. So, it happens.

 

[knuckle47]

Hoping for some good results with the timing !

 

[Grayscale]

In the process I managed to dislodge and drop my brake master reservoir lid. It hit the ground in my small garage and totally vanished. I just spent the last 45 minutes looking everywhere for it. I threw a baggie over the top and will look again tomorrow.

I lost a pair of keys, for six months, in the compost. When I found it, the ring was almost rotted in half, and the adjacent corrosion cleaned chrome off of the OEM part. I dropped a valve spring keeper down a push-rod hole, then lost a magnet chasing after it, I can't remember how I fished it out, but, I remember that the head had a bore smaller than the block, and the step that I faced with retrieval was a challenge. Parts just disappear, and with it quite a bit of shop-time. I knew a guy who worked at a car dealer service center, and his job ended because he left a spark plug in the engine bay. The previous owner lost all kinds of awesome hardware in the frame rail, a book of matches and a pocket-knife behind the dash board.

 

[knuckle47]

A friend works at McGuire AFB as a jet mechanic…he said they had to inventory everything and every tool brought to the aircraft after a job was completed before it could be cleared for take-off.

We live in the same house 45 years…. My son was 18 months old in 1982 and JUST TO KEEP HIM QUIET we let him play with my wife’s check book register…we have ripped up carpets, moved furniture, painted 15 times, replaced windows, even replaced drywall in some rooms…never found that check book register…that dumb paper thing the size of small checks that you probably had 5 of back in the old days

 

[MatthewMcD]

I lost a pair of keys, for six months, in the compost. When I found it, the ring was almost rotted in half, and the adjacent corrosion cleaned chrome off of the OEM part. I dropped a valve spring keeper down a push-rod hole, then lost a magnet chasing after it, I can't remember how I fished it out, but, I remember that the head had a bore smaller than the block, and the step that I faced with retrieval was a challenge. Parts just disappear, and with it quite a bit of shop-time. I knew a guy who worked at a car dealer service center, and his job ended because he left a spark plug in the engine bay. The previous owner lost all kinds of awesome hardware in the frame rail, a book of matches and a pocket-knife behind the dash board.

I religiously stuff shop towels into the intake because I am certain I'll drop a nut or washer and it'll cost me a day or more. (Have you read the post about the guy who found the remnants of a ring clamp in his cylinder?)

 

[MatthewMcD]

A friend works at McGuire AFB as a jet mechanic…he said they had to inventory everything and every tool brought to the aircraft after a job was completed before it could be cleared for take-off.

We live in the same house 45 years…. My son was 18 months old in 1982 and JUST TO KEEP HIM QUIET we let him play with my wife’s check book register…we have ripped up carpets, moved furniture, painted 15 times, replaced windows, even replaced drywall in some rooms…never found that check book register…that dumb paper thing the size of small checks that you probably had 5 of back in the old days

Sounds like when we'd audit the surgical trays after a surgery. Working for a mischievous older vet, we would do "post op" radiographs to be sure there was nothing left behind. He would slip a clamp under the sleeping dog laying on the radiograph plate. He wouldn't tell the younger surgical resident about the joke until they had scrubbed in and gotten ready to go after the clamp.

 

[RevISK]

Beetlejuice

I just threw in the low 4 suggestion because I have a buddy with a jeep scrambler that calls me up and says that he put it in gear and nothing was happening. He said no forward or reverse. I said is your transfer case in neutral? All I got was silence in the other end. He just said aww man I can’t believe I did that. So, it happens.

jeep owner though.

 

[MatthewMcD]

Hoping for some good results with the timing !

Thanks! We'll get it. I just needed a break today.

 

[Skreddy]

The head hasn't changed since the PO though, and they didn't have the issue; right?

This is starting to need a spreadsheet.

PO “says” they didn’t have the issue…..