Cam card confusion
Race Director
Joined: May 2005
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From: Millington Illinois
St. Jude Donor '08-'09
Here is a complete rotating assembly with forged pistons, bearings, rings, ect for the same money as your crank, rods, KB crap hyper pistons. Both need balancing but the rotating assembly I linked will balance with no mallory. If your put together combo needs mallory (likely with the lightweight crank)your looking at a lot of $ to balance.
http://www.cnc-motorsports.com/rotat...h-pistons.html
Your talking pushing the envelope on DCR forged pistons are the way to go especially if they don't cost more.
http://www.cnc-motorsports.com/rotat...h-pistons.html
Your talking pushing the envelope on DCR forged pistons are the way to go especially if they don't cost more.
Last edited by 63mako; Jan 6, 2013 at 03:16 PM.
Thread Starter
Le Mans Master
Joined: Apr 2011
Posts: 6,284
Likes: 1,171
From: Hermosa
2 out of 3 is getting there. I have seen more than enough problems with KB pistons, go with coated or even uncoated SpeedPro pistons and yes building a motor costs money but you saved a ton of money on these parts that will be more than enough for the level of HP you are shooting for, don't stop now and get it all balanced.
Both need balancing but the rotating assembly I linked will balance with no mallory. If your put together combo needs mallory (likely with the lightweight crank)your looking at a lot of $ to balance.
http://www.cnc-motorsports.com/rotat...h-pistons.html
Your talking pushing the envelope on DCR forged pistons are the way to go especially if they don't cost more.
Today 12:54 PM
Your talking pushing the envelope on DCR forged pistons are the way to go especially if they don't cost more.
Today 12:54 PM
Do the 6" con rods present anymore of a clearance issue vs the 5.7" rods?
Really appreciate you guys helping me out on this. Obviously I would have already made some mistakes due to my inexperience were it not for the help I get here.
Race Director
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From: Who says "Nothing is impossible" ? I've been doing nothing for years.
There seems to be 2 cast cranks from CNC Motorsports site.
1) the Scat 9-10442 Pro Stock Cast Steel Replacement Crankshaft $179 and
2) the other is the Scat 9-350-3750-6000 9000 Series Cast Steel Pro Comp Crankshaft $229 from the CNC Motorsports site.
From the Scat site they list the same cranks as
1) CHEVY 9-10442 CAST PRO STOCK REPLACEMENT CRANKSHAFTS
and
2) CHEVY 9-350-3750-6000 CAST PRO COMP STROKER LIGHTWEIGHT CRANKSHAFTS
None of the Pro Stock Cast Steel Replacement Crankshaft use 6 in. rods so in other words, the crank in the CNC kit is lightweight
1) the Scat 9-10442 Pro Stock Cast Steel Replacement Crankshaft $179 and
2) the other is the Scat 9-350-3750-6000 9000 Series Cast Steel Pro Comp Crankshaft $229 from the CNC Motorsports site.
From the Scat site they list the same cranks as
1) CHEVY 9-10442 CAST PRO STOCK REPLACEMENT CRANKSHAFTS
and
2) CHEVY 9-350-3750-6000 CAST PRO COMP STROKER LIGHTWEIGHT CRANKSHAFTS
None of the Pro Stock Cast Steel Replacement Crankshaft use 6 in. rods so in other words, the crank in the CNC kit is lightweight
Thread Starter
Le Mans Master
Joined: Apr 2011
Posts: 6,284
Likes: 1,171
From: Hermosa
looking at these pistons wouldn't a guy be better served by a piston with a squish pad vs one that just has a ring around the perimeter?
http://www.cnc-motorsports.com/pisto...-chevy_sb.html
http://www.cnc-motorsports.com/pisto...-chevy_sb.html
http://www.cnc-motorsports.com/pisto...-chevy_sb.html
http://www.cnc-motorsports.com/pisto...-chevy_sb.html
Race Director
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From: Who says "Nothing is impossible" ? I've been doing nothing for years.
It gets a little confusing but this is the crank you want from CNC
Scat 9-350-3750-5700 9000 Series Cast Steel Pro Comp Crankshaft
$229.95
Manufacturer: Scat
Small Block Chevy 383, 3.750 Stroke, 2.449(350 Main), 2.100 Rod Journal, 5.700 or Longer Rod, External Balance, Approximate Weight 51 LBS, 2 Piece Rear Seal
The 5.7 Scat Rods you already picked
And if your SCR is that low SpeedPro Hyperutectic Pistons to get you whatever static CR you are shooting for. The ICON Pistons are made by the same company that makes the KB pistons. I paid $800 for the forged pistons in my 427ci
Those parts were in my 406ci that made 550HP and 510TQ. So I really post from my own personal experience not to say anyone else doesn't do the same.
6000 RPM !
Scat 9-350-3750-5700 9000 Series Cast Steel Pro Comp Crankshaft
$229.95
Manufacturer: Scat
Small Block Chevy 383, 3.750 Stroke, 2.449(350 Main), 2.100 Rod Journal, 5.700 or Longer Rod, External Balance, Approximate Weight 51 LBS, 2 Piece Rear Seal
The 5.7 Scat Rods you already picked
And if your SCR is that low SpeedPro Hyperutectic Pistons to get you whatever static CR you are shooting for. The ICON Pistons are made by the same company that makes the KB pistons. I paid $800 for the forged pistons in my 427ci
Those parts were in my 406ci that made 550HP and 510TQ. So I really post from my own personal experience not to say anyone else doesn't do the same.
6000 RPM !
Race Director
Joined: May 2005
Posts: 10,674
Likes: 122
From: Millington Illinois
St. Jude Donor '08-'09
There seems to be 2 cast cranks from CNC Motorsports site.
1) the Scat 9-10442 Pro Stock Cast Steel Replacement Crankshaft $179 and
2) the other is the Scat 9-350-3750-6000 9000 Series Cast Steel Pro Comp Crankshaft $229 from the CNC Motorsports site.
From the Scat site they list the same cranks as
1) CHEVY 9-10442 CAST PRO STOCK REPLACEMENT CRANKSHAFTS
and
2) CHEVY 9-350-3750-6000 CAST PRO COMP STROKER LIGHTWEIGHT CRANKSHAFTS
None of the Pro Stock Cast Steel Replacement Crankshaft use 6 in. rods so in other words, the crank in the CNC kit is lightweight
1) the Scat 9-10442 Pro Stock Cast Steel Replacement Crankshaft $179 and
2) the other is the Scat 9-350-3750-6000 9000 Series Cast Steel Pro Comp Crankshaft $229 from the CNC Motorsports site.
From the Scat site they list the same cranks as
1) CHEVY 9-10442 CAST PRO STOCK REPLACEMENT CRANKSHAFTS
and
2) CHEVY 9-350-3750-6000 CAST PRO COMP STROKER LIGHTWEIGHT CRANKSHAFTS
None of the Pro Stock Cast Steel Replacement Crankshaft use 6 in. rods so in other words, the crank in the CNC kit is lightweight
Lightweight will rev quicker, 6" rods use lighter pistons which allow you to balance a lightweight crank with fewer issues. That is why this kit is matched up together. 6" rods also dwell a little longer up top and have less side loading on a 3.750 stroke with better internal clearance. Internal balanced is better than external. The above are why I recommended the kit I did. If you want something different go for it but this is a lot of rotating assembly for minimal money.
Race Director
Joined: May 2005
Posts: 10,674
Likes: 122
From: Millington Illinois
St. Jude Donor '08-'09
looking at these pistons wouldn't a guy be better served by a piston with a squish pad vs one that just has a ring around the perimeter?
http://www.cnc-motorsports.com/pisto...-chevy_sb.html
http://www.cnc-motorsports.com/pisto...-chevy_sb.html
http://www.cnc-motorsports.com/pisto...-chevy_sb.html
http://www.cnc-motorsports.com/pisto...-chevy_sb.html
Thread Starter
Le Mans Master
Joined: Apr 2011
Posts: 6,284
Likes: 1,171
From: Hermosa
Lightweight will rev quicker, 6" rods use lighter pistons which allow you to balance a lightweight crank with fewer issues. That is why this kit is matched up together. 6" rods also dwell a little longer up top and have less side loading on a 3.750 stroke with better internal clearance. Internal balanced is better than external. The above are why I recommended the kit I did. If you want something different go for it but this is a lot of rotating assembly for minimal money.
This is really more complicated than I anticipated. So many compramises to be made when trying to stay in some kind of a budget.
Over on E-bay I can get a short block assembly for a 383 for $1700. Wonder how junkie those are?
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Race Director
Joined: May 2005
Posts: 10,674
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From: Millington Illinois
St. Jude Donor '08-'09
Thanks Mako63 appreciate the help. Noticed it also has the 1/16 rings on that piston. currently my bores have a 240 grit finish on them, these rings good with that you think?
This is really more complicated than I anticipated. So many compramises to be made when trying to stay in some kind of a budget.
Over on E-bay I can get a short block assembly for a 383 for $1700. Wonder how junkie those are?
This is really more complicated than I anticipated. So many compramises to be made when trying to stay in some kind of a budget.
Over on E-bay I can get a short block assembly for a 383 for $1700. Wonder how junkie those are?
Thread Starter
Le Mans Master
Joined: Apr 2011
Posts: 6,284
Likes: 1,171
From: Hermosa
Your finish is for chrome rings. Moly like 400 surface finish which you can still do. That kit comes with 4.005 piston option too which would be great if you finish the hone at a machine shop to 4.005 with torque plate and stones if your measurements are accurate.
Today 08:45 PM
Today 08:45 PM
Those holes will definately clean up 4.005.
Race Director
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From: Who says "Nothing is impossible" ? I've been doing nothing for years.
Not sure you can hone a cylinder .005" ask your machine shop, I know my brand new 400 block came in at at little less than 4.125" and my machine shop bored and honed it to get 4.125, boring it also makes sure the cylinders are round.
Yes it does get complicated, but it is an every day thing for a good machine shop, make sure you find a good one so you get everything right the first time. Deck height on all four corners should be measured and decked to make everything square, this was also done on my brand new block.
Yes it does get complicated, but it is an every day thing for a good machine shop, make sure you find a good one so you get everything right the first time. Deck height on all four corners should be measured and decked to make everything square, this was also done on my brand new block.
Race Director
Joined: May 2005
Posts: 10,674
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From: Millington Illinois
St. Jude Donor '08-'09
Honing .005 is no problem. Torque plate and step hone with stones. 80 grit, 150 grit 220 grit, 400 grit or similar. Need your pistons, rings and a good shop. If your wear is as minimal as you think no problem.
Thread Starter
Le Mans Master
Joined: Apr 2011
Posts: 6,284
Likes: 1,171
From: Hermosa
Not sure you can hone a cylinder .005" ask your machine shop, I know my brand new 400 block came in at at little less than 4.125" and my machine shop bored and honed it to get 4.125, boring it also makes sure the cylinders are round.
Honing .005 is no problem. Torque plate and step hone with stones. 80 grit, 150 grit 220 grit, 400 grit or similar. Need your pistons, rings and a good shop. If your wear is as minimal as you think no problem.
Race Director
Joined: May 2005
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From: Millington Illinois
St. Jude Donor '08-'09
Yes round is probably pretty critical with those 1/16' moly rings.
So they wouldn't bore it ot 4.005 then? To little material I suppose. I'm sure they could let me know if it's round enough to hone it over. Really boring to 4.010 would be no big deal if that's what it would take to get them nice and round, just better check before I order the kit. Still not super keen on the piston top design. Looks just like my stock pistons and they were terrible for squish.
So they wouldn't bore it ot 4.005 then? To little material I suppose. I'm sure they could let me know if it's round enough to hone it over. Really boring to 4.010 would be no big deal if that's what it would take to get them nice and round, just better check before I order the kit. Still not super keen on the piston top design. Looks just like my stock pistons and they were terrible for squish.
Thread Starter
Le Mans Master
Joined: Apr 2011
Posts: 6,284
Likes: 1,171
From: Hermosa
Been doing a little reading on the Keith black pistons. Sounds like they got a bad rap due to the amount of heat that is transfered into the top ring. Guys would set the ring gap a the standard .016 to .020 and the gap wold close up on them and destroy the top ring land and the cylinder and maybe the head too.
KB recommends more like .030 to .038 for a 4" bore due to the heat sinking feature of their pistons.
Is this the kind of issues you guys are referring to when talking about Keith black pistons?
KB recommends more like .030 to .038 for a 4" bore due to the heat sinking feature of their pistons.
Is this the kind of issues you guys are referring to when talking about Keith black pistons?
Race Director
Joined: May 2005
Posts: 10,674
Likes: 122
From: Millington Illinois
St. Jude Donor '08-'09
Been doing a little reading on the Keith black pistons. Sounds like they got a bad rap due to the amount of heat that is transfered into the top ring. Guys would set the ring gap a the standard .016 to .020 and the gap wold close up on them and destroy the top ring land and the cylinder and maybe the head too.
KB recommends more like .030 to .038 for a 4" bore due to the heat sinking feature of their pistons.
Is this the kind of issues you guys are referring to when talking about Keith black pistons?
KB recommends more like .030 to .038 for a 4" bore due to the heat sinking feature of their pistons.
Is this the kind of issues you guys are referring to when talking about Keith black pistons?
Thread Starter
Le Mans Master
Joined: Apr 2011
Posts: 6,284
Likes: 1,171
From: Hermosa
According to their page the top ring is located to reflect more heat back into the combustion chamber making more power. This is why more clearance is needed for the ring ends.
http://www.bcheads.com/kb1.htm
http://www.bcheads.com/kb1.htm
Race Director
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Posts: 17,676
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From: Who says "Nothing is impossible" ? I've been doing nothing for years.
Thread Starter
Le Mans Master
Joined: Apr 2011
Posts: 6,284
Likes: 1,171
From: Hermosa
Looking around again for some option to these pistons with this kit. I also notice that the compression height is dropped .005" to 1.125 instead of the 1.130 to get me .025 down the bore, so another hit to the squish band.
http://www.cnc-motorsports.com/pisto...-005-bore.html
These pistons however have a nice squish pad and a CH of 1.130 both would be to good effect. Cost is $100 more so have to talk to CNC and see if they could or would do the swap. Weight difference is 16 grams heavier. That doesn't seem like too much should still balance alright shouldn't it? Is it possoble for these 1/16" rings to seal on a less than perfect bore? I would at least have to get a 400 grit finish on them I suppose.
Otherwise the only way to use them would be to bore out to 4.030".
http://www.cnc-motorsports.com/pisto...-000-bore.html
http://www.cnc-motorsports.com/pisto...-005-bore.html
These pistons however have a nice squish pad and a CH of 1.130 both would be to good effect. Cost is $100 more so have to talk to CNC and see if they could or would do the swap. Weight difference is 16 grams heavier. That doesn't seem like too much should still balance alright shouldn't it? Is it possoble for these 1/16" rings to seal on a less than perfect bore? I would at least have to get a 400 grit finish on them I suppose.
Otherwise the only way to use them would be to bore out to 4.030".
http://www.cnc-motorsports.com/pisto...-000-bore.html
Race Director
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From: Who says "Nothing is impossible" ? I've been doing nothing for years.
The new C6SZ06 427ci LS7 uses hypereutectic pistons. Don't underestimate this type of piston. If it were me and it was with the 406ci in the video above that made 550HP I would use SpeedPro hypereutectic over $300 forged made by the same company that makes the Kieth Black pistons.
Take a look at the price for good forged pistons from Mahle, Wiesco etc. they are double to triple the price as those ICON pistons. Makes me wonder why they are so cheap, my rule of thumb is you get what you pay for
Take a look at the price for good forged pistons from Mahle, Wiesco etc. they are double to triple the price as those ICON pistons. Makes me wonder why they are so cheap, my rule of thumb is you get what you pay for