Home  |  Forums  |  914 Info  |  Blogs
 
914World.com - The fastest growing online 914 community!
 
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.
 

Welcome Guest ( Log In | Register )

 
 Reply to this topicStart new topic
> Puttin together a Raby kit engine, Deck Height revisited
DNHunt
post Aug 28 2004, 10:31 AM
Post #1


914 Wizard? No way. I got too much to learn.
****

Group: Members
Posts: 4,099
Joined: 21-April 03
From: Gig Harbor, WA
Member No.: 598
Building this has been a blast. I have certainly learned a lot. Jake has been very patient and given me plenty of rope but, when I've started to wander he's tugged me back in line.

Deck Height has been a revelation. My first attempts were all over the place. After working on this for a total of 8 hours I really believe we've got a handle on it. I've learned a bunch.

First, these are very small dimensions. Jake wanted the deck within .004" on all 4 cylinders. We really struggled with this. Check this out a single sheet of paper is between .002 and .003.


Attached image(s)
Attached Image
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
red914
post Aug 28 2004, 10:39 AM
Post #2


...i believe in coyotes and time as an abstract...
***

Group: Members
Posts: 862
Joined: 8-February 04
From: poulsbo, washington
Member No.: 1,641
i sure hope i can see this beauty when you are done. keep us posted; it is awesome to follow along! (IMG:style_emoticons/default/clap56.gif)
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
DNHunt
post Aug 28 2004, 10:40 AM
Post #3


914 Wizard? No way. I got too much to learn.
****

Group: Members
Posts: 4,099
Joined: 21-April 03
From: Gig Harbor, WA
Member No.: 598
When we put the cylinders and pistons on the first time, the pistons were proud of the cylinders a bunch so I couldn't torque the heads. We took some measurements but, they weren't good for anything but an approximation. So, I ordered some .140" shims from Rimco. It also was apparent that the cylinders would need to be clamped all the way around the mating surface so I got a big piece of channel iron and had it surfaced. When I used that I got the measurements with in .010. Still not good enough.

Big piece of steel.

You can see how nice and even the clamping presure is from the cylinders marking the tool.


Attached image(s)
Attached Image
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
DNHunt
post Aug 28 2004, 10:58 AM
Post #4


914 Wizard? No way. I got too much to learn.
****

Group: Members
Posts: 4,099
Joined: 21-April 03
From: Gig Harbor, WA
Member No.: 598
We tried switching cylinders and that didn't help. So, we switched rods, wrist pins and pistons from 2 and 3. (Jake engraves numbers in all of the rods, wrist pins and cylinders so if you keep the same numbers together it is in balance) That got us to .006. Damn, just a little more than 2 sheets of scratch paper off but still, not good enough. I measured the shims. They were right on. I tried moving the cylinders, no good. I went to bed Thursday night really depressed. I was sure something was really wrong like the align bore was off.

I woke up Friday after a crappy night of sleep stewing over my problem. Before work I went out tp the garage and looked over the case. The cylinder registers on 2 and 3 looked kind of dirty. So I got out some carb cleaner and went to work. Sure enough they cleaned up. After work I retried everything. I'm now within .002

Here's the dial indicator zeroed at top dead center #3


Attached image(s)
Attached Image
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
DNHunt
post Aug 28 2004, 11:00 AM
Post #5


914 Wizard? No way. I got too much to learn.
****

Group: Members
Posts: 4,099
Joined: 21-April 03
From: Gig Harbor, WA
Member No.: 598
Here's the deck of #3 .062 at the outside edge


Attached image(s)
Attached Image
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
DNHunt
post Aug 28 2004, 11:11 AM
Post #6


914 Wizard? No way. I got too much to learn.
****

Group: Members
Posts: 4,099
Joined: 21-April 03
From: Gig Harbor, WA
Member No.: 598
Time to order some more shims. Jake said for me shoot for a .060 deck and a compression ratio of 9.8:1. I can't get both to the targets. Either the deck has to be tighter than .060 or the compression ratio hasto be lower than the target. I'm leaning towards .0134" shims and a deck of.056 with a CR of 9.7:1.

Jake's on vacation right now so I won't be making a final decision until he gets back.

Here's the whole rig on the left bank of cylinders

Dave


Attached image(s)
Attached Image
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
DNHunt
post Aug 28 2004, 12:11 PM
Post #7


914 Wizard? No way. I got too much to learn.
****

Group: Members
Posts: 4,099
Joined: 21-April 03
From: Gig Harbor, WA
Member No.: 598
Welcome to the real world son. Gerry's doin the math to figure out compression ratio on a Saturday morning during summer vacation. Dad's a slave driver.

Dave


Attached image(s)
Attached Image
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
thesey914
post Aug 28 2004, 01:30 PM
Post #8


Senior Member
***

Group: Benefactors
Posts: 1,155
Joined: 1-January 03
From: Staffordshire -England
Member No.: 66
Gerry should be thankful you're letting him use a calculator -not long division (IMG:style_emoticons/default/biggrin.gif)
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
Demick
post Aug 28 2004, 01:43 PM
Post #9


Ernie made me do it!
****

Group: Benefactors
Posts: 2,312
Joined: 6-February 03
From: Pleasanton, CA
Member No.: 257
Here's the easy way to figure out the C.R.:

aircooled.net calculator

Demick
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
seanery
post Aug 28 2004, 02:09 PM
Post #10


waiting to rebuild whitey!
***************

Group: Retired Admin
Posts: 15,854
Joined: 7-January 03
From: Indy
Member No.: 100
Region Association: None
Must be really tough math! TWO Calculators! (IMG:style_emoticons/default/laugh.gif)
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
GWN7
post Aug 28 2004, 02:37 PM
Post #11


King of Road Trips
*****

Group: Members
Posts: 6,280
Joined: 31-December 02
From: Winnipeg, MB, Canada
Member No.: 56
Region Association: Northstar Region
QUOTE
TWO Calculators!


You have to have back up (IMG:style_emoticons/default/smile.gif)
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
Porsche Rescue
post Aug 28 2004, 04:46 PM
Post #12


Saving and Enjoying Old Porsches
****

Group: Members
Posts: 2,978
Joined: 31-December 02
From: Bend, Oregon
Member No.: 64
Region Association: None
Ok Dave, I have no shame. What exactly is "deck height"? The distance between what and what?
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
Brett W
post Aug 28 2004, 04:51 PM
Post #13


Advanced Member
****

Group: Members
Posts: 2,858
Joined: 17-September 03
From: huntsville, al
Member No.: 1,169
Region Association: None
You will have a bigger problem with detonation at a .060 deck than you will with an .040. What pistons are you running? What are you running for piston to wall clearence?
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
LS6/914
post Aug 28 2004, 08:25 PM
Post #14


Never leaves the shop member
**

Group: Members
Posts: 301
Joined: 1-October 03
From: Port Townsend,WA Rivabelosa/Madrid ESP
Member No.: 1,215
Region Association: Pacific Northwest
Dave, Give a call if you need a extra hand, dial indicator, bore gauge, caliper, deck mic. I will be in the harbor monday-wed. Lar
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
« Next Oldest · 914World Garage · Next Newest »
 

Reply to this topicStart new topic
1 User(s) are reading this topic (1 Guests and 0 Anonymous Users)
0 Members:

 

Display Mode: Standard · Switch to: Linear+ · Switch to: Outline

Track this topic · Email this topic · Print this topic · Subscribe to this forum

- Lo-Fi Version Time is now: 21st April 2025 - 05:27 AM
Invision Power Board v9.1.4 © 2025  IPS, Inc.
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 ...