Austin's 1977 Tintop Camper

[wwebner]

Too late now,but you can use the flywheel to help hold the crank.

[Kooper271]

Starting to look like an engine... hope to get the heads on tonight

[Kooper271]

Got 1 piston installed. Deck height measured .018" so with no shims I will be at ~7.8:1 compression. I am kind of confused on how my deck height is so low, though. I don't think I could have messed it up, I used feeler gauges and a machinist's edge

[wwebner]

I think a cheap digital caliper may be more accurate than the feeler gauges.
Double check and then check again .018 does not seem correct.
Also,another hint. Polish the snout of the fan hub where it protrudes thru the seal and wipe a thin film of assembly lube or oil on the snout.

Also,if you consistently get .018 for deck HT and your are certain that that is correct,you will need to shim the cylinders at the case. What did you end up with for head cc? I have a feeling there is something wrong with a measurement somewhere.

[Kooper271]

I measured 59cc for the head. I used 69cc in the calculation because the dished pistons are ~10cc.

I have a digital caliper but don't know how to use it to measure deck height. Am I supposed to add on the step in the head anywhere?

[Kooper271]

Another question: How easily should wrist pins install? I had to beat on mine to get them in.

[wwebner]

Another question: How easily should wrist pins install? I had to beat on mine to get them in.

Were the rods re bushed? should not have to beat them in. Are they hanging in the piston? or the rod?

Now. About your deck ht. first 7.8:1 comp ratiois fine.(good)

Here's what I came up with. Try measuring your deck ht with the digital calipers like this.

This should confirm or correct your deck ht. measurement.
Now it gets a little confusing.
Ratwell claims the step in the AMC heads is .080. But I noticed he is using metric scale, but that would be .031in.I don't have a stepped head to measure,but you can,using the same method for measuring deck ht. Measure it.
That would make your actual deck ht. .018 + .031 = .049 which is ok.
If I measure the spacer that the AMC step is replacing, I get .030 so we're close.
You have already taken into your formula the volume of the step.when you cc'd the head. SO,I am sorry for the confusion. Damn stepped heads.
I am assuming,and will verify with Jonathan at AA,that their pistons are a bit taller to compensate for the step in the AMC heads.
That's why I would prefer machining the step out of the AMC head and setting the DESIRED deck ht with shims at the cylinder base. But that is more of an anal blueprinting issue.
I think you are going to be just fine.

[Kooper271]

Another question: How easily should wrist pins install? I had to beat on mine to get them in.

Were the rods re bushed? should not have to beat them in. Are they hanging in the piston? or the rod?

Now. About your deck ht. first 7.8:1 comp ratiois fine.(good)

Here's what I came up with. Try measuring your deck ht with the digital calipers like this.
deck & shim 001.jpg
This should confirm or correct your deck ht. measurement.
Now it gets a little confusing.
Ratwell claims the step in the AMC heads is .080. But I noticed he is using metric scale, but that would be .031in.I don't have a stepped head to measure,but you can,using the same method for measuring deck ht. Measure it.
That would make your actual deck ht. .018 + .031 = .049 which is ok.
If I measure the spacer that the AMC step is replacing, I get .030 so we're close.
You have already taken into your formula the volume of the step.when you cc'd the head. SO,I am sorry for the confusion. Damn stepped heads.
I am assuming,and will verify with Jonathan at AA,that their pistons are a bit taller to compensate for the step in the AMC heads.
That's why I would prefer machining the step out of the AMC head and setting the DESIRED deck ht with shims at the cylinder base. But that is more of an anal blueprinting issue.
I think you are going to be just fine.

The rods were rebushed. The wrist pin is hanging up in the piston, not the rod. I think I'm going to heat the pistons and freeze the wrist pins.

Thank you for checking on all of that for me, Bill. I really appreciate it.

[wwebner]

I would not do the heat and cool. When the parts get back to the same temp your still going to be tight.
Use an appropriate size fine abrasive flapper wheel to polish the pin bore in the piston. I had to do this with John's.
It is a safe way to do it as you are not taking too much material out of the pin bore.

[chuckspence]

I usually dry check the fit of the wrist pins prior to assembly, if they're tight I'll polish them on my lathe with fine emery cloth & clean up the bore in the pistons but that's normally just for used pistons/pins, new pistons & pins should fit better, did you get the AA pistons or Mahle? I've never had an issue with Mahle & I've never used AA's, might just be an extra prep step one needs to do when using AA type 4 pistons...

Bill is mostly correct, however tight fit in the piston is OK as long as they're loose (correct) in the rod bushing...

curious that you were set on purchasing a set of costly cylinder heads (HAM https://newsite.hamheads.com/2017/01/16 ... nderheads/) yet opted for a set of less costly pistons/cylinders, while proven quality Mahle's are not that much more $$$.