octanejunkie
Mopar Padawan
Supposedly, the block was magged by the PO, but I may consider it when having it square-decked, perhaps right before hand!
My 360 Magnum build thread
- Thread starter octanejunkie
- Start date
-
Supposedly, the block was magged by the PO, but I may consider it when having it square-decked, perhaps right before hand!
octanejunkie
Mopar Padawan
Took several more sets of measurements over the weekend, refining my process and accuracy potential, and now, finally, I can get consistent and repeatable measurements of each pistons' deck clearance within .0005"
I bought a digital dial indicator from harbor freight for $29. Re-mounted on my harbor freight magnetic base, squared up the rods and indicator, and took ALL play out of the setup. I also refined my procedure by rechecking zero after each measurement on a 3/4" sheet of glass that was lying around in the garage.
Obviously the last variable is the deck surface that I am mounting the magnetic base to and how consistent/square that is. Even though I standardized every other aspect of the process, this is the last variable (beside rod length and piston compression height) I have no control over at this point.
After repeated measurements that were all within .0005 I now feel confident in my ability to measure piston-to-deck clearance accurately, at least as accurate as the deck surface allows mounting of the magnetic base. Here are the latest and most accurate and repeatable measurements to date:
[FONT=Verdana, Helvetica, Arial]
1 .0040 (8 )----.0035/.0045
3 .0035---------.0030/.0045
5 .0035---------.0030/.0040
7 .0045 (T)-----.0045/.0045
2 .0050 (K)-----.0040/.0050
4 .0045---------.0040/.0055
6 .0070---------.0065/.0075
8 .0070 (A)-----.0065/.0070[/FONT]
These measurements are the result of multiple passes on each bank (minimum of 5) and then averaged together. The column on the right shows the lowest/highest per cylinder and the values in parenthesis are the rod markings, otherwise all rod/piston combos are in their correct bores.
Taking the averaging aspect one step farther, if I average each bank we see that 1-7 is on average .004 in the hole and 2-8 is .006 in the hole. The only reason this is vaguely important is that if the decks are relatively close to square already, which I doubt, and the minimum cut Kelly's can make is .005," then I know that some pistons may pop out of the bores by .001 or so, but until the decks are square and I mock it up and measure again this is all just hot air.
Next step will be taking the block in, next update after that, hopefully with pics of the square-decking process.
I bought a digital dial indicator from harbor freight for $29. Re-mounted on my harbor freight magnetic base, squared up the rods and indicator, and took ALL play out of the setup. I also refined my procedure by rechecking zero after each measurement on a 3/4" sheet of glass that was lying around in the garage.
Obviously the last variable is the deck surface that I am mounting the magnetic base to and how consistent/square that is. Even though I standardized every other aspect of the process, this is the last variable (beside rod length and piston compression height) I have no control over at this point.
After repeated measurements that were all within .0005 I now feel confident in my ability to measure piston-to-deck clearance accurately, at least as accurate as the deck surface allows mounting of the magnetic base. Here are the latest and most accurate and repeatable measurements to date:
[FONT=Verdana, Helvetica, Arial]
1 .0040 (8 )----.0035/.0045
3 .0035---------.0030/.0045
5 .0035---------.0030/.0040
7 .0045 (T)-----.0045/.0045
2 .0050 (K)-----.0040/.0050
4 .0045---------.0040/.0055
6 .0070---------.0065/.0075
8 .0070 (A)-----.0065/.0070[/FONT]
These measurements are the result of multiple passes on each bank (minimum of 5) and then averaged together. The column on the right shows the lowest/highest per cylinder and the values in parenthesis are the rod markings, otherwise all rod/piston combos are in their correct bores.
Taking the averaging aspect one step farther, if I average each bank we see that 1-7 is on average .004 in the hole and 2-8 is .006 in the hole. The only reason this is vaguely important is that if the decks are relatively close to square already, which I doubt, and the minimum cut Kelly's can make is .005," then I know that some pistons may pop out of the bores by .001 or so, but until the decks are square and I mock it up and measure again this is all just hot air.
Next step will be taking the block in, next update after that, hopefully with pics of the square-decking process.
1wild&crazyguy
Banned
I wouldn't worry about it.
My 410's P/DH has a .006 variance, I could care less cause it probably affects 1/10th of 1 hp if at all.jmo
My 410's P/DH has a .006 variance, I could care less cause it probably affects 1/10th of 1 hp if at all.jmo
octanejunkie
Mopar Padawan
BUT MY MOTOR MUST BE PERFECT!
Kidding, actually I am trying to attain optimal quench, so yes I am obsessing a bit, but will ultimately tune the rest with gasket choice. I may or may not re-size rods depending on what everything measures out at after square decking; musical pistons is always an option too...
For me, this is more of an experiment in procedure (to refine,) a way to gain experience (with mopar stuff) and will serve as a practical comparison against my recent SBC motor that did not undergo such critical scrutiny during build up. As they say, YMMV, or in this case mine, but it should prove to be a good exercise as long as no one gets hurt or broke.
Thanks for your conciliatory post, I know I am going above and beyond the ordinary, but that is also relative to what circle of hell we each end up in, no?
1wild&crazyguy
Banned
ya got whats his face at .028 quench distance, hughes says .035 is what they like, above .040 is a wash, how tight is optimal for you and your pistons?
octanejunkie
Mopar Padawan
Looking for .039-ish, a tad less wouldn't hurt, hopefully, but .028 is too close for comfort for me...
octanejunkie
Mopar Padawan
I dropped off the magnum block at Kelly's this morning. We reviewed the measurements I took and decided to take the average off each deck as per my calculations, .004 off bank 1-7 and .006" off bank 2-8. Should be done within a week, will post an update and pics post square-decking.
POS Dakota
Anti-Socialist
Sounds good!
mopardude318
Well-Known Member
cool! keep us posted
octanejunkie
Mopar Padawan
It's been months since I got the block back from Kellys.
I did a quick mock up of the cranks and rods/pistons to check deck height and found that a few of my pistons now pop above the deck by 1 to 2 thou, which makes me uneasy about using an .039 gasket...
The next potential issue I have is when I mounted the rods to the crank I overtightened the rod caps a bit too strong, not sure if I could have squished the rod bearings...
So the two questions I have are:
1. should I address the piston-pop-up issue by
a. have the rods resized
b. have the piston tops cut down on a lathe
2. Should I order new rod bearings to be safe
Hope everything has been good for all here, sorry to have been gone so long!
I did a quick mock up of the cranks and rods/pistons to check deck height and found that a few of my pistons now pop above the deck by 1 to 2 thou, which makes me uneasy about using an .039 gasket...
The next potential issue I have is when I mounted the rods to the crank I overtightened the rod caps a bit too strong, not sure if I could have squished the rod bearings...
So the two questions I have are:
1. should I address the piston-pop-up issue by
a. have the rods resized
b. have the piston tops cut down on a lathe
2. Should I order new rod bearings to be safe
Hope everything has been good for all here, sorry to have been gone so long!
MopaR&D
Nerd Member
I'm actually building a 360 Magnum as well, based off dgc333's high-compression high-quench build. My difference though is I'm using a '79 360 LA block and freshened Magnum heads I got from 64physhy, a Lunati Voodoo hyd. flat-tappet 256/262 cam from my old 318, and KB-107s.
I'm kind of stuck in the same boat with the high-precision machining too, I had the block cleaned and cylinders honed but didn't ask to have the deck heights checked. I also have to get the rotating assembly balanced. Do you think my 1979 block decks and connecting rods are better or worse than your 1999 Magnum parts? I'm going to bring the parts in to school one of these days and measure them but time is tight and I don't have anyone to help me lift the block off my garage floor LOL...
I'm kind of stuck in the same boat with the high-precision machining too, I had the block cleaned and cylinders honed but didn't ask to have the deck heights checked. I also have to get the rotating assembly balanced. Do you think my 1979 block decks and connecting rods are better or worse than your 1999 Magnum parts? I'm going to bring the parts in to school one of these days and measure them but time is tight and I don't have anyone to help me lift the block off my garage floor LOL...
moper
Well-Known Member
Don't worry about a quench thighter than .039. The 360s not a big bore, the pistons are tall, you're running a steel rod, and you can go much tighter. If it was me I'd be aiming for .030-.032 for quench so I think you're fine. The less the quench distance, the better the more effective it is. On the bearings... You won't squich the bearings so much as stretch the bolts... This is really easy to do. However, if you have to replace the bolts, that rod needs to be re-sized.
Keep up the good work! (and welcome to blueprinting...lol)
Keep up the good work! (and welcome to blueprinting...lol)
1wild&crazyguy
Banned
You're fine.
.037 quench is great for what you're doing and plenty safe.
You would have to other issues to be hitting at that distance.
octanejunkie
Mopar Padawan
Thanks for the encouragement moper, I THOUGHT I torqued those rod bolts to 35 ft lbs, nothing super crazy, but then I noticed the crank got tough to rotate and worked backwards. I can gauge the rod bolts but I think they are probably ok; or should i send the rods out?
Speaking of blueprinting, I'm at the point of laying the crank in it's final resting place and sealing it up - plastigauge it or just go for it?
Also, I have a windage tray that should fit the 360, should I use these milodon main studs from summit?
Speaking of blueprinting, I'm at the point of laying the crank in it's final resting place and sealing it up - plastigauge it or just go for it?
Also, I have a windage tray that should fit the 360, should I use these milodon main studs from summit?
1wild&crazyguy
Banned
you either need a new torque wrench or your rods/crank need to be checked and machined to correct spec.
octanejunkie
Mopar Padawan
So I ordered some green plastigauge and checked clearances on all crank journals. Looked pretty good actually:
1 - .003
2 - .002
3 - .002
4 - .002
5 - .00175 ?
Here is a pic, as best as I could manage working alone trying to avoid the glare of the lamp
Here is the rear main cap, clearly thinner than the others...
If I'm reading my manual correctly, crank clearances are supposed to be between .0005 and .0020 - not sure if I should be concerned about the #1 cap being over .0020
I also thought about checking clearances on all the rods but only got to one, here is how it looked
From my tech manual, rod clearance is supposed to be between .0005 and .0022 to - this rod looks to be right in the range
I made sure my torque wrench was correct and tightened all bolts to proper spec, according to my manual 85 lbs-ft for the mains and 45 lbs-ft for the rods, in 10 ft-lb increments.
After all clearances are checked and confirmed I will disassemble and debur all freeze/threaded plug holes and run a tap through all crank and head bolt threads; then a thorough cleaning and painting of the block before assembly.
I will need to make sure my main cap bolt holes are threaded all the way down so the milodon main studs fully engage, per their instructions, as I will be installing a windage tray.
1 - .003
2 - .002
3 - .002
4 - .002
5 - .00175 ?
Here is a pic, as best as I could manage working alone trying to avoid the glare of the lamp
Here is the rear main cap, clearly thinner than the others...
If I'm reading my manual correctly, crank clearances are supposed to be between .0005 and .0020 - not sure if I should be concerned about the #1 cap being over .0020
I also thought about checking clearances on all the rods but only got to one, here is how it looked
From my tech manual, rod clearance is supposed to be between .0005 and .0022 to - this rod looks to be right in the range
I made sure my torque wrench was correct and tightened all bolts to proper spec, according to my manual 85 lbs-ft for the mains and 45 lbs-ft for the rods, in 10 ft-lb increments.
After all clearances are checked and confirmed I will disassemble and debur all freeze/threaded plug holes and run a tap through all crank and head bolt threads; then a thorough cleaning and painting of the block before assembly.
I will need to make sure my main cap bolt holes are threaded all the way down so the milodon main studs fully engage, per their instructions, as I will be installing a windage tray.
-
