IDIBRONCO
IDIBRONCO
Even though he screwed up my heads by milling too much off of them, the "machinist" that worked on my heads did install new hardware to go along with my Comp 910 springs.
6.9 IDI Build
- Thread starter WarNose
- Start date
Comp 910s are not too stiff, I run them in all of my builds, the shop truck being one and it sees 4000+ rpms daily with no issues.
WarNose
Full Access Member
Summit and a few other places list the 910 springs at 380 lbs/inch. Jegs lists them at 458 lbs/inch. I assume that the Jegs number is wrong.
Does anyone know the rate of stock springs? My math comes up with 302.5 lbs/inch. Closed height of 1.8 inches minus open height of 1.4 inches equals 0.4 inches spring travel. 197 lbs open pressure minus 76 lbs closed pressure equals 121 pounds from closed to open. 121 pounds divided by 0.4 inches equals 302.5 lbs/inch spring rate. Is that correct?
Does anyone know the rate of stock springs? My math comes up with 302.5 lbs/inch. Closed height of 1.8 inches minus open height of 1.4 inches equals 0.4 inches spring travel. 197 lbs open pressure minus 76 lbs closed pressure equals 121 pounds from closed to open. 121 pounds divided by 0.4 inches equals 302.5 lbs/inch spring rate. Is that correct?
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DrCharles
Full Access Member
Comp Cams spring table is on page 12 of this document:
http://www.compcams.com/catalog/comp2012/pdf/comp_catalog_2012_328-361.pdf
910 shows as 415 lb/in.
http://www.compcams.com/catalog/comp2012/pdf/comp_catalog_2012_328-361.pdf
910 shows as 415 lb/in.
WarNose
Full Access Member
It took a little convincing, but I got him to install the 910's.
WarNose
Full Access Member
I got my parts baxk from the shop juat in time for the Christmas slowdown at work.
Here is the metal fresh from the machine shop.
So far I have painted it, installed piston squirters, camshaft, and crankshaft.
It literally took all day and into the night to install the crankshaft. This included cleaning up the threads a bit, degreasing the flexplate bolt holes, checking clearances with plastigauge, checking crankshaft endplay, and final torquing. I'm glad that my son is old enough to help me move that heavy crankshaft around.
Main clearances all showed around .002 to .0025 according to the plastigauge.
Crankshaft endplay measured at .007 when pried from one direction to the other.
Main caps torqued to 95 lbs/ft.
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Here is the metal fresh from the machine shop.
You must be registered for see images attach
You must be registered for see images
So far I have painted it, installed piston squirters, camshaft, and crankshaft.
You must be registered for see images attach
It literally took all day and into the night to install the crankshaft. This included cleaning up the threads a bit, degreasing the flexplate bolt holes, checking clearances with plastigauge, checking crankshaft endplay, and final torquing. I'm glad that my son is old enough to help me move that heavy crankshaft around.
Main clearances all showed around .002 to .0025 according to the plastigauge.
Crankshaft endplay measured at .007 when pried from one direction to the other.
Main caps torqued to 95 lbs/ft.
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WarNose
Full Access Member
I can't figure out my my links to imgur pics won't work.
Edit: I figured it out. I have to switch the setting on the Imgur website to "direct link."
Edit: I figured it out. I have to switch the setting on the Imgur website to "direct link."
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WarNose
Full Access Member
Piston Ring End Gaps?
This is what I have found on this site:
6.9
top ring: .014-.024
2nd ring: .060-.070
oil control ring: .010-.024
7.3
top ring: .013-.045
2nd ring: .060-.085
oil control ring: not listed
I have also read that the 7.3 numbers are the same for both N/A and turbo models. Being that 6.9's never came with a turbo, I should be able to use the same 6.9 numbers then? Should I lean toward the larger spectrum since it is bored .020 over and will be turbo-ed?
Also, on the oil ring, the gap is for the top and bottom retainer rings right? No need to gap the middle spring ring?
Thanks.
This is what I have found on this site:
6.9
top ring: .014-.024
2nd ring: .060-.070
oil control ring: .010-.024
7.3
top ring: .013-.045
2nd ring: .060-.085
oil control ring: not listed
I have also read that the 7.3 numbers are the same for both N/A and turbo models. Being that 6.9's never came with a turbo, I should be able to use the same 6.9 numbers then? Should I lean toward the larger spectrum since it is bored .020 over and will be turbo-ed?
Also, on the oil ring, the gap is for the top and bottom retainer rings right? No need to gap the middle spring ring?
Thanks.
I lean to the tighter ends of the spec for pistons rings on the second comp ring, with only being 20 over you don’t need to worry about changing the spec much to compensate for the change in ring circumference. On oil rings you don’t need to worry about the inner spring, most the oil rings from sealed power have been good out of the box.
WarNose
Full Access Member
Thank you!
hacked89
Full Access Member
Coming along nice. How did you learn to rebuild a motor? Are there any books you would suggest? Or just have to do it and ask someone a ton of questions as you go? I've always wanted to but even looking at the rebuild kit I barely know how to figure out the answers to the questions or what things mean
Sent from my SM-G955U using Tapatalk
Sent from my SM-G955U using Tapatalk
Frstdiesel
Full Access Member
Did you install the freeze plugs or your machine shop?
If machine shop did what method did they use?
Curious.
Thanks
If machine shop did what method did they use?
Curious.
Thanks
WarNose
Full Access Member
I'm using a book called "Engine Builders Handbook" by Tom Monroe. Here is a link: https://www.amazon.com/Engine-Builders-Handbook-Tom-Monroe/dp/1557882452
I am also using this site a ton. There is no better source for these motors. I did a ton of research on this site and read that book a few times before deciding to give the motor building thing a try.
I also had to invest in some tools, such as a good torque wrench, ring expanders and compressors, etc.
WarNose
Full Access Member
The machine shop installed them. I asked about the special International tool. He said he did not have it and would use a regular large punch to install them. He assured me not to worry, that he has installed many of them over the last 40 years without a problem. I decided to trust him, but I will verify. As Icanfixall suggests, I am going to pressurize the coolant system with water to 30 psi before installing the motor.
WarNose
Full Access Member
These piston rings are driving me crazy. The oil ring gaps are at the top of the spec range, ranging from .019 to .024. I feel like I should send them back but that would set my build back few days. They are Hastings rings.
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