Big bore case machining....., How big is too big???? |
|
Porsche, and the Porsche crest are registered trademarks of Dr. Ing. h.c. F. Porsche AG.
This site is not affiliated with Porsche in any way. Its only purpose is to provide an online forum for car enthusiasts. All other trademarks are property of their respective owners. |
|
Big bore case machining....., How big is too big???? |
crash914 |
Jul 30 2004, 10:22 AM
Post
#1
|
its a mystery to me Group: Members Posts: 1,826 Joined: 17-March 03 From: Marriottsville, MD Member No.: 434 Region Association: MidAtlantic Region |
Ok, case is at the shop being bored out for 103mm Nickies....
The cylinder slides in very nice, but the hole is real close to cutting into the threads for the head studs... my question, is this ok? I don't want to torque the studs too tight and put a bind on the cylinder... any one got pictures for a 103mm machined case? Thanks, herb |
Jake Raby |
Jul 30 2004, 10:35 AM
Post
#2
|
Engine Surgeon Group: Members Posts: 9,394 Joined: 31-August 03 From: Lost Member No.: 1,095 Region Association: South East States |
tell the machinist to center off the existing bore and cut 108.5mm in diameter. Its not too close at all at that bore. I have completely cut into studs before with no issues.
|
crash914 |
Jul 30 2004, 10:46 AM
Post
#3
|
its a mystery to me Group: Members Posts: 1,826 Joined: 17-March 03 From: Marriottsville, MD Member No.: 434 Region Association: MidAtlantic Region |
Thanks Jake, this is what we are doing....
I will post a picture this weekend when I pick up the case. It just looks like if you cut into the threads, there is a large gap for an oil leak... I know blue silicone will seal it up, (IMG:style_emoticons/default/wink.gif) but I don't really want to leak oil... thanks, herb |
Jake Raby |
Jul 30 2004, 12:51 PM
Post
#4
|
Engine Surgeon Group: Members Posts: 9,394 Joined: 31-August 03 From: Lost Member No.: 1,095 Region Association: South East States |
with your cylinders you should be far away from the case studs.. ensure that you cutters are set up right, I think you may have an issue.. Look at my webpage under research and see the 3.0 build up, even my 105s are not into the studs
|
crash914 |
Jul 30 2004, 01:23 PM
Post
#5
|
its a mystery to me Group: Members Posts: 1,826 Joined: 17-March 03 From: Marriottsville, MD Member No.: 434 Region Association: MidAtlantic Region |
(IMG:style_emoticons/default/sad.gif) yes, I did take a picture of your 3.0 with me...
I am right at 108.5, (4.2716") mine actually measures (4.270)" Let me get a couple of pictures as I am not into the threads, but very very close (at least to me). I was thinking that your 105's have a thinner wall.. The bore was dialed in before cutting so we are centered, I thought about moving the center of the bore, but just left it where it is. I have a very nice slip fit, with a little wiggle room. based on your comments, I should be good to go!!! I just need lifters (IMG:style_emoticons/default/sad.gif) (IMG:style_emoticons/default/confused24.gif) Thanks for the help, herb |
Jake Raby |
Jul 30 2004, 01:56 PM
Post
#6
|
Engine Surgeon Group: Members Posts: 9,394 Joined: 31-August 03 From: Lost Member No.: 1,095 Region Association: South East States |
did he center off the studs, or the existing register?
|
crash914 |
Jul 30 2004, 01:58 PM
Post
#7
|
its a mystery to me Group: Members Posts: 1,826 Joined: 17-March 03 From: Marriottsville, MD Member No.: 434 Region Association: MidAtlantic Region |
centered off the existing bore...
With new cylinder in place, studs are perfect. I should be in good shape. thanks again...herb |
Jake Raby |
Jul 30 2004, 02:21 PM
Post
#8
|
Engine Surgeon Group: Members Posts: 9,394 Joined: 31-August 03 From: Lost Member No.: 1,095 Region Association: South East States |
sweet!
When you torque up the heads, call me I have a trick for ya! |
crash914 |
Jul 31 2004, 06:07 AM
Post
#9
|
its a mystery to me Group: Members Posts: 1,826 Joined: 17-March 03 From: Marriottsville, MD Member No.: 434 Region Association: MidAtlantic Region |
Now for some out of focus porn......
Attached image(s) |
crash914 |
Jul 31 2004, 06:11 AM
Post
#10
|
its a mystery to me Group: Members Posts: 1,826 Joined: 17-March 03 From: Marriottsville, MD Member No.: 434 Region Association: MidAtlantic Region |
Wait! that wasn't it....
Attached image(s) |
crash914 |
Jul 31 2004, 06:13 AM
Post
#11
|
its a mystery to me Group: Members Posts: 1,826 Joined: 17-March 03 From: Marriottsville, MD Member No.: 434 Region Association: MidAtlantic Region |
Nickie's got head...
Attached image(s) |
Mark Henry |
Jul 31 2004, 06:29 AM
Post
#12
|
that's what I do! Group: Members Posts: 20,065 Joined: 27-December 02 From: Port Hope, Ontario Member No.: 26 Region Association: Canada |
Shhhhwing!!!!
(IMG:style_emoticons/default/beer.gif) (IMG:style_emoticons/default/monkeydance.gif) (IMG:style_emoticons/default/boldblue.gif) (IMG:style_emoticons/default/smilie_pokal.gif) (IMG:style_emoticons/default/cool.gif) |
thesey914 |
Jul 31 2004, 11:12 AM
Post
#13
|
Senior Member Group: Benefactors Posts: 1,155 Joined: 1-January 03 From: Staffordshire -England Member No.: 66 |
Shame all that will be hidden under the fan shroud. I know the flat6 is hidden too but with the fan it makes the engine bar sexy....
|
crash914 |
Jul 31 2004, 05:41 PM
Post
#14
|
its a mystery to me Group: Members Posts: 1,826 Joined: 17-March 03 From: Marriottsville, MD Member No.: 434 Region Association: MidAtlantic Region |
Now for the money shot....
Attached image(s) |
seanery |
Jul 31 2004, 05:43 PM
Post
#15
|
waiting to rebuild whitey! Group: Retired Admin Posts: 15,852 Joined: 7-January 03 From: Indy Member No.: 100 Region Association: None |
Herb, who's pistons?
What's the expected CR? It looks BE U Tiful! |
crash914 |
Jul 31 2004, 05:52 PM
Post
#16
|
its a mystery to me Group: Members Posts: 1,826 Joined: 17-March 03 From: Marriottsville, MD Member No.: 434 Region Association: MidAtlantic Region |
I have about 0.020" positive piston height...looks like 0.060" shims for me.....
Jake, have any other suggestions? Attached image(s) |
crash914 |
Jul 31 2004, 05:58 PM
Post
#17
|
its a mystery to me Group: Members Posts: 1,826 Joined: 17-March 03 From: Marriottsville, MD Member No.: 434 Region Association: MidAtlantic Region |
These are 103mm Nickies, J&E forged pistons, 22mm pin 80mm crank with chevy journal....Scat rods, Jake cam....
For compression ratio, I am shooting for above 10:1....I am not sure about the final one yet...depends on pump gas and how much I want to blend my own gas...I only drive this about 1000 miles per year...not at all this year. The motor is now ready for re-assembly....I will need to order cylinder shims, but that should be a quick turn around.... Wait till you see it all assembled with the fuel injection throttle bodies.....got wood just thinking about it..... (IMG:style_emoticons/default/wub.gif) |
Mark Henry |
Jul 31 2004, 09:17 PM
Post
#18
|
that's what I do! Group: Members Posts: 20,065 Joined: 27-December 02 From: Port Hope, Ontario Member No.: 26 Region Association: Canada |
I think I better go change my underwear. (IMG:style_emoticons/default/cool_shades.gif)
|
crash914 |
Aug 2 2004, 07:44 AM
Post
#19
|
its a mystery to me Group: Members Posts: 1,826 Joined: 17-March 03 From: Marriottsville, MD Member No.: 434 Region Association: MidAtlantic Region |
(IMG:style_emoticons/default/icon_bump.gif)
Just thinking about compression ratios....10:1 or 11:1 (IMG:style_emoticons/default/idea.gif) |
Jake Raby |
Aug 2 2004, 09:53 AM
Post
#20
|
Engine Surgeon Group: Members Posts: 9,394 Joined: 31-August 03 From: Lost Member No.: 1,095 Region Association: South East States |
Herb,
That cam works best at 9.5:1... Believe it or not it makes MORE power at 9.5, than at 10:1 or higher.... |
Lo-Fi Version | Time is now: 21st May 2024 - 01:42 AM |
All rights reserved 914World.com © since 2002 |
914World.com is the fastest growing online 914 community! We have it all, classifieds, events, forums, vendors, parts, autocross, racing, technical articles, events calendar, newsletter, restoration, gallery, archives, history and more for your Porsche 914 ... |