My 360 Magnum build thread
So I assembled the rotating bits over the last few days, lots of fun to be building another engine, forgot how much I enjoy this stage.
I checked the crank journal/bearing/cap clearances, got .004 crank/thrust clearance, set thrust on the crank forward and torqued it down to 85lbs, turns nicely.
Checked ring gaps, .018 measured at 3 depths and orientation in the bores - looks good there...
Began inspection on the piston/rod combos, pistons were already pressed to rods when I acquired them. Found 3 rods NOT marked with numbers, letters used, suspect replacement rods? I designeated them as follows, for now...
Rod marked [FONT=Verdana, Helvetica, Arial]A, used as #1
[/FONT]Rod marked [FONT=Verdana, Helvetica, Arial]K, used as #2
[/FONT]Rod marked [FONT=Verdana, Helvetica, Arial]T, used as #7[/FONT]
Since I suspect some rod length variation, and cannot accurately measure the RODS with the pistons already mounted, I decided to install ALL piston/rod combos in one cyl, I chose cyl #8 for this task. Here is how they compared off the deck surface:
[FONT=Verdana, Helvetica, Arial]1 .0030 (rod marked A)
3 .0040
5 .0020
7 .0120 (rod marked T)
2 .0095 (rod marked K)
4 .0010
6 .0075
8 .0058[/FONT]
That's quite some variation... While mulling it over and holding back the tears I decided that there are too many unknown variables to make this more than anecdotal info so I moved on and installed the 4 corners and here is what I got
[FONT=Verdana, Helvetica, Arial]1 -.0015 (A marked rod)[/FONT][FONT=Verdana, Helvetica, Arial]7 .0035 (T marked rod)
2 .0030 (K marked rod)[/FONT][FONT=Verdana, Helvetica, Arial]
8 .0100
Ouch! #1 is above the deck and #8 is .010 in the hole... now I wonder how straight the decks are, so I decided to install all 8 and see how they line up, it got more interesting:
[/FONT][FONT=Verdana, Helvetica, Arial]1 -.0015 (A marked rod)
3 .0015
5 .0015
7 .0035 (T marked rod)
2 .0030 (K marked rod)
4 .0030
6 .0060
8 .0100[/FONT]
Since 3 rods seem NOT to be original to this assembly, I decided to play musical pistons and swapped #1 and #8, which seemed initially logical, and ended up with:
[FONT=Verdana, Helvetica, Arial]1 .0015 (8 )
3 .0015
5 .0020
7 .0025 (T)
2 .0030 (K)
4 .0030
6 .0060
8 .0075 (A)[/FONT]
So now I might be ready to discuss cutting decks/squaring with my shop. Obviously I still have a few issues to consider, like how accurate and repeatable are my measurements. Assuming all things being equal, it would seem that the decks are higher in the rear and need to be squared but this may not be so.
Talked to Al at L&B Con Rod Service in Anaheim, he can re-size all or some of my rods for a nominal fee, less than $20 each, which includes sizing the big ends and converting small ends from press-fit to full-floating - he can move the center of the wrist pin bore, oversize it, and bush the pin to get the rod lengths even - I might consider this for #6 and A rods once I see how the deck squares out
Would love to hear everyone's thoughs, in the meantime, here are a few pics.
So I assembled the rotating bits over the last few days, lots of fun to be building another engine, forgot how much I enjoy this stage.
I checked the crank journal/bearing/cap clearances, got .004 crank/thrust clearance, set thrust on the crank forward and torqued it down to 85lbs, turns nicely.
Checked ring gaps, .018 measured at 3 depths and orientation in the bores - looks good there...
Began inspection on the piston/rod combos, pistons were already pressed to rods when I acquired them. Found 3 rods NOT marked with numbers, letters used, suspect replacement rods? I designeated them as follows, for now...
Rod marked [FONT=Verdana, Helvetica, Arial]A, used as #1
[/FONT]Rod marked [FONT=Verdana, Helvetica, Arial]K, used as #2
[/FONT]Rod marked [FONT=Verdana, Helvetica, Arial]T, used as #7[/FONT]
Since I suspect some rod length variation, and cannot accurately measure the RODS with the pistons already mounted, I decided to install ALL piston/rod combos in one cyl, I chose cyl #8 for this task. Here is how they compared off the deck surface:
[FONT=Verdana, Helvetica, Arial]1 .0030 (rod marked A)
3 .0040
5 .0020
7 .0120 (rod marked T)
2 .0095 (rod marked K)
4 .0010
6 .0075
8 .0058[/FONT]
That's quite some variation... While mulling it over and holding back the tears I decided that there are too many unknown variables to make this more than anecdotal info so I moved on and installed the 4 corners and here is what I got
[FONT=Verdana, Helvetica, Arial]1 -.0015 (A marked rod)[/FONT][FONT=Verdana, Helvetica, Arial]7 .0035 (T marked rod)
2 .0030 (K marked rod)[/FONT][FONT=Verdana, Helvetica, Arial]
8 .0100
Ouch! #1 is above the deck and #8 is .010 in the hole... now I wonder how straight the decks are, so I decided to install all 8 and see how they line up, it got more interesting:
[/FONT][FONT=Verdana, Helvetica, Arial]1 -.0015 (A marked rod)
3 .0015
5 .0015
7 .0035 (T marked rod)
2 .0030 (K marked rod)
4 .0030
6 .0060
8 .0100[/FONT]
Since 3 rods seem NOT to be original to this assembly, I decided to play musical pistons and swapped #1 and #8, which seemed initially logical, and ended up with:
[FONT=Verdana, Helvetica, Arial]1 .0015 (8 )
3 .0015
5 .0020
7 .0025 (T)
2 .0030 (K)
4 .0030
6 .0060
8 .0075 (A)[/FONT]
So now I might be ready to discuss cutting decks/squaring with my shop. Obviously I still have a few issues to consider, like how accurate and repeatable are my measurements. Assuming all things being equal, it would seem that the decks are higher in the rear and need to be squared but this may not be so.
Talked to Al at L&B Con Rod Service in Anaheim, he can re-size all or some of my rods for a nominal fee, less than $20 each, which includes sizing the big ends and converting small ends from press-fit to full-floating - he can move the center of the wrist pin bore, oversize it, and bush the pin to get the rod lengths even - I might consider this for #6 and A rods once I see how the deck squares out
Would love to hear everyone's thoughs, in the meantime, here are a few pics.
