| FAQ |
| Members List |
| Social Groups |
| Calendar |
| Search |
| Today's Posts |
|
#1
08-08-2008, 09:42 AM
|
||||
|
||||
Zero deck or -.00x ?
69 428 4 bolt main. After measuring several times using a magnetic base dial indicator I ended up concluding that I have a .025 deck height at all 4 corners. There were some variations, at times, depending on how the magnetic base was placed/moved. The deck has slight rough spots where water passages on the heads are exposed to the deck.
Current rotating assembly is 10/10 stock crank, stock rebuilt rods, TRW forged slugs which have had the tops sanded and polished. I hope to replace the rods and pistons in a future build with better and newer parts. It's all apart to replace a rear main seal. I want to go ahead and have it decked to improve quench and bump my compression a tad so the cam I plan to run will have a little more DCR. Should I go for "ZERO" or leave it .00x (like .003 or .005) in the hole?
__________________
 68 Firebird, trying a q-jet now. 434/10.5:1/997's/240-242 HFT/4L80E/2800 Yank/3.42's/ Vintage Air/ 13.0 @105 mph 70 Lemans, 350/350, A/C, mostly stock 14 Ram CC, 5.7 Hemi, 8-speed, 3.92 lsd 97 Trans Am, HPP Aug 2012 http://www.highperformancepontiac.co...tiac_trans_am/ ***Sold*** |
|
#2
08-08-2008, 09:45 AM
|
||||
|
||||
|
Some guys like to leave it 0.003-0.005 just for some clean up room if they blow a head gasket and burn the block a little.
__________________
Skip Fix 1978 Trans Am original owner 10.99 @ 124 pump gas 455 E heads, NO Bird ever! 1981 Black SE Trans Am stockish 6X 400ci, turbo 301 on a stand 1965 GTO 4 barrel 3 speed project 2004 GTO Pulse Red stock motor computer tune 13.43@103.4 1964 Impala SS 409/470ci 600 HP stroker project 1979 Camaro IAII Edelbrock head 500" 695 HP 10.33@132 3595lbs |
|
#3
08-08-2008, 09:50 AM
|
||||
|
||||
|
They only time it becomes a major issue is when your pushing the envelope on compression and cam profile. Taking the sharp edges out of the chambers would do more if your at the compression limit.
|
|
#4
08-08-2008, 08:05 PM
|
||||
|
||||
|
Could leave 'em in the hole .005" to .010" and run a .027" C/T cometic head gasket.
That would keep the quench pad where you want it,and bump up the CR slightly,and as suggested above still leave some room for a clean-up or two down the road someday. That set-up with the cometics is close to what you get with a zero deck deal and the "common" .039" to .042" C/T headgaskets,and after the deck "clean-ups" later on you would just adjust the quench distance with those "common" C/T headgaskets to keep the quench & CR the same. That's often a little easier on the headgasket too,especially helpful with boost apps and such. But I digress... 
|
|
#5
08-08-2008, 09:17 PM
|
|||
|
|||
|
tee hee hee..i'd run it .005 out with the thin gaskets, but i'm considered a lunatic..
|
|
#6
08-09-2008, 01:32 AM
|
||||
|
||||
|
After switching blocks and pistons for the first one ,my IA2 ended up arouns 0.005 out.My machinist said he has seen kiss marks at 0.030 with light SBC stuff so he wanted me to us 0.050 gaskets-Cometics.
__________________
Skip Fix 1978 Trans Am original owner 10.99 @ 124 pump gas 455 E heads, NO Bird ever! 1981 Black SE Trans Am stockish 6X 400ci, turbo 301 on a stand 1965 GTO 4 barrel 3 speed project 2004 GTO Pulse Red stock motor computer tune 13.43@103.4 1964 Impala SS 409/470ci 600 HP stroker project 1979 Camaro IAII Edelbrock head 500" 695 HP 10.33@132 3595lbs |
|
#7
08-09-2008, 02:49 AM
|
|||
|
|||
|
if the piston shows carbon, its not making peak power..
|
|
#8
08-09-2008, 09:39 AM
|
||||
|
||||
|
The machinist suggested leaving them in a little since the crank and rods have been machine before. I was ready to set them at zero but decided to leave the smallest margin and asked for .023 removed which should leave .002 down. When I picked it up he said he removed exactly .023 so I just have to put it together and see. After I got it home and was cleaning it up again I noticed he put a healthy radius at the top of some of the bores. Not the same at every bore but some were as large as 1/16". I'm glad they didn't leave a knife edge but is that ok?
Also, if you guys could please chime in on my cam bearings. My 2nd and 4th cam bearings have smaller holes than the other ones. Can this be right? Pics are here. http://forums.maxperformanceinc.com/...d.php?t=570503
__________________
68 Firebird, trying a q-jet now. 434/10.5:1/997's/240-242 HFT/4L80E/2800 Yank/3.42's/ Vintage Air/ 13.0 @105 mph 70 Lemans, 350/350, A/C, mostly stock 14 Ram CC, 5.7 Hemi, 8-speed, 3.92 lsd 97 Trans Am, HPP Aug 2012 http://www.highperformancepontiac.co...tiac_trans_am/ ***Sold*** |
| Reply |
|
|
The PY Online Forums is the largest online gathering of Pontiac enthusiasts anywhere in the world. Founded in 1991, it was also the first online forum for people to gather and talk about their Pontiacs. Since then, it has become the mecca of Pontiac technical data and knowledge that no other place can surpass.
Linear Mode
