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
> KABOOM!, The F Production scatters!
Jake Raby
post Jul 9 2004, 11:31 AM
Post #1


Engine Surgeon
*****

Group: Members
Posts: 9,394
Joined: 31-August 03
From: Lost
Member No.: 1,095
Region Association: South East States
Damn, what a bad Friday....It was running better than ever before!

Here are the details that we know now.
http://www.shoptalkforums.com/viewtopic.php?t=74056

I'm sure we lost a part, probably a rod- will know next week and will share some pics of some of the carnage..

This is our first failure in 3 years, and this one was a doozey, I doubt anything is salvageable!
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
Andyrew
post Jul 9 2004, 11:46 AM
Post #2


Spooling.... Please wait
**********

Group: Members
Posts: 13,376
Joined: 20-January 03
From: Riverbank, Ca
Member No.: 172
Region Association: Northern California
Ouch man..

I guess we learn from our mistakes right? So you have to make a mistake to learn!

(not saying you havent made a mistake.. its just this is one of the only one's we've heard of...)

Sorry to hear this, but I hope you find a way to make it stronger, better, faster.

Andrew
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
Jake Raby
post Jul 9 2004, 12:17 PM
Post #3


Engine Surgeon
*****

Group: Members
Posts: 9,394
Joined: 31-August 03
From: Lost
Member No.: 1,095
Region Association: South East States
Someone made a mistake along the line... Either the manufacturers of the parts, or me and my crazy risk taking way of assembling things...
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
Andyrew
post Jul 9 2004, 12:38 PM
Post #4


Spooling.... Please wait
**********

Group: Members
Posts: 13,376
Joined: 20-January 03
From: Riverbank, Ca
Member No.: 172
Region Association: Northern California
So, your saying the parts should be able to handle this kind of abuse, you just think that since this is a super high end engine, it must need everything to be perfect, and someone screwed up somewhere...

Andrew
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
Jake Raby
post Jul 9 2004, 12:48 PM
Post #5


Engine Surgeon
*****

Group: Members
Posts: 9,394
Joined: 31-August 03
From: Lost
Member No.: 1,095
Region Association: South East States
These parts had been handling the power just fine for 3 years... Nothing was changed except the cam and it was just modified with a newer billet and modified lobe centers.

I made changes to the combo to increase the powerband another 800 RPM. The extra revs and added CR found a weak link somewhere. The engine previously would pull to 8K, but would not make power that high... Now the new combo would make power at 7,800 RPM.. It went 1 rev too high and scattered..

My bet is the rod bolts broke, they cost 30 bucks each!

At these kinds of revs anything can happen.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
davep
post Jul 9 2004, 02:24 PM
Post #6


914 Historian
*****

Group: Benefactors
Posts: 5,141
Joined: 13-October 03
From: Burford, ON, N0E 1A0
Member No.: 1,244
Region Association: Canada
You can always learn from your mistakes. It is more difficult to learn from your successes. That is a law of nature. Sorry to hear that it blew up. We know the next generation will be all the better for it. (IMG:style_emoticons/default/beer.gif)
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
grantsfo
post Jul 9 2004, 02:31 PM
Post #7


Arrrrhhhh!
****

Group: Members
Posts: 4,327
Joined: 16-March 03
Member No.: 433
Region Association: None
It blew at 7500 rpm. Wow I get nervous when I get north of 5500 rpm. Type 4 must sound wild at those kind of rpms
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
Jake Raby
post Jul 9 2004, 02:40 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
The engines powerband STARTS at 5500 RPM! Driving one at high RPM is one thing, but the dyno is even more scary up that high..

My street car turns 8300 no sweat..
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
davep
post Jul 9 2004, 02:58 PM
Post #9


914 Historian
*****

Group: Benefactors
Posts: 5,141
Joined: 13-October 03
From: Burford, ON, N0E 1A0
Member No.: 1,244
Region Association: Canada
I'll bet the marine training helps there. Nerves of steel when under fire. You have guts, that is for sure.
Too bad the car will not have an engine for a while. That is the real problem. It is not like there are sufficient parts ready on the shelf and it can be put together during an all-nighter.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
rick 918-S
post Jul 9 2004, 03:04 PM
Post #10


Hey nice rack! -Celette
***************

Group: Members
Posts: 20,456
Joined: 30-December 02
From: Now in Superior WI
Member No.: 43
Region Association: Northstar Region
Jake,

What is the connecting rod ratio of your high reving type IV's? I know when a stock rod length is used in a BMW 2002 the ratio is 1.6875. Which means the motor will live at 6875 RPM's all day and ask for more. But when pushed over 7000 rpm's the crank speed and the piston speed become unequal. This results in the failure of the rod at the small end. It is literally jerked apart as the wieght of the crank and the speed of the piston work against each other. To increase the rev's longer rods are used with a custom piston. If your moving the rev's and power up 800 rpm's you may want to follow the BMW theory. Just something to consider... (IMG:style_emoticons/default/confused24.gif) I respect your work and knowledge of the type IV's. Your the expert not me.

Nevermind... I just read the othe post. My question is too engine specific.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
Rich Bontempi
post Jul 9 2004, 04:05 PM
Post #11


914 Road Racer
**

Group: Members
Posts: 167
Joined: 5-February 03
From: Redwood City Ca. 94063
Member No.: 239
Region Association: Northern California
Jake, What kind of rods are you using? Since I went to carrillo rods 20 years ago, we haven't lost a rod or rod bolt. I always shift at 8,000 to 8,500 in my F/P 914.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
Brett W
post Jul 9 2004, 04:37 PM
Post #12


Advanced Member
****

Group: Members
Posts: 2,856
Joined: 17-September 03
From: huntsville, al
Member No.: 1,169
Region Association: None
Rich, the FP engine uses the stock 1.8 connecting rod ratio which is 1.95. Not a bad ratio for such RPMs, slows the piston speed considerably. Rules don't allow any change in the ratio.

Carrillo has had a bad batch of rods in the past, but they are indeed one of the best available.

In my opinion three seasons on those parts is a long time to run them. Maybe too long. How many hours did the motor have one it?
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
fiid
post Jul 9 2004, 05:09 PM
Post #13


Turbo Megasquirted Subaru Member
****

Group: Members
Posts: 2,827
Joined: 7-April 03
From: San Francisco, CA
Member No.: 530
Region Association: Northern California
Bummer dude. I'm sure you'll learn a lot when you examine what happened.

Fiid.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
Randal
post Jul 9 2004, 06:16 PM
Post #14


Advanced Member
****

Group: Members
Posts: 4,446
Joined: 29-May 03
From: Los Altos, CA
Member No.: 750
Jake,

You should be bragging about that motor, i.e., three seasons. My buddies running hot 6's on the track are getting 25 hours total and you know what that rebuild costs!

Randal
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: 15th May 2024 - 12:40 AM
Invision Power Board v9.1.4 © 2024  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 ...