INTAKE MANIFOLD QUESTION. |
|
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. |
|
INTAKE MANIFOLD QUESTION. |
JOE M |
Apr 10 2009, 05:07 AM
Post
#1
|
Member Group: Members Posts: 293 Joined: 27-August 07 From: N.H Member No.: 8,042 Region Association: None |
I just removed my intakes and old carbs. I found that there was a spacer between the manifolds and block that is apx. 1/2" thick. It is made out of some type of material that is similar to carbon fiber. Im not sure exactly what it is but 1 of the spacers is broke. Is this part needed or was the P.O doing something funny. There are 2 spacers 1 per side.
|
dbgriffith75 |
Apr 10 2009, 05:29 AM
Post
#2
|
TheGrif Group: Members Posts: 509 Joined: 25-July 07 From: Iowa, USA Member No.: 7,945 Region Association: Upper MidWest |
I'm not sure why there'd be 2 per side... the PO must've been doing something screwy because there should only be one gasket (spacer) per side. Well, technically 3- the thick gasket should have 2 thin ones on either side of it... or so Rich would have us believe. (IMG:style_emoticons/default/biggrin.gif)
|
BarberDave |
Apr 10 2009, 05:45 AM
Post
#3
|
Barberdave Group: Members Posts: 1,605 Joined: 12-January 03 From: Wauseon Ohio Member No.: 135 Region Association: Upper MidWest |
(IMG:style_emoticons/default/smilie_pokal.gif)
Thick casket sandwiched between 2 thin ones, the thin act as a seal between the head thick 1, and likewise for the other with the manofold. The thick one , ( has a name i can't pronouce ) it's just a insulator . I keeps the heat from the block from progressing up to the carbs and thus the gas. Dave (IMG:style_emoticons/default/slap.gif) |
SLITS |
Apr 10 2009, 10:52 AM
Post
#4
|
"This Utah shit is HARSH!" Group: Benefactors Posts: 13,602 Joined: 22-February 04 From: SoCal Mountains ... Member No.: 1,696 Region Association: None |
Single setup .... it's a Bakelite Insulator with two paper gaskets glued to it. Paper forms the seal ... Bakelite is the insulator..
|
SirAndy |
Apr 10 2009, 11:56 AM
Post
#5
|
Resident German Group: Admin Posts: 41,854 Joined: 21-January 03 From: Oakland, Kalifornia Member No.: 179 Region Association: Northern California |
Stock FI gaskets. You should be able to get them from all the usual parts suppliers ...
(IMG:style_emoticons/default/bye1.gif) Andy |
maf914 |
Apr 10 2009, 01:20 PM
Post
#6
|
Not a Guru! Group: Members Posts: 3,049 Joined: 30-April 03 From: Central Florida Member No.: 632 Region Association: None |
When using dual Webbers should the FI insulators be used at the base of the manifolds or not? Reduce heat transfer to the manifolds or let the manifolds heat up to promote fuel atomization?
I have used the insulators with carbs but I was never sure about it. (IMG:style_emoticons/default/idea.gif) |
SirAndy |
Apr 10 2009, 01:47 PM
Post
#7
|
Resident German Group: Admin Posts: 41,854 Joined: 21-January 03 From: Oakland, Kalifornia Member No.: 179 Region Association: Northern California |
let the manifolds heat up to promote fuel atomization? Sounds good in theory, but that's not how it works. Carbs suck huge amounts of air through a small opening, thus dissipating a lot of heat. Ever heard of carbs "icing" up? Go for a spirited run and immediately get out and touch your carbs. They'll be very cold. The same principle is used in refrigerators to cool down the air inside. What the thick FI gaskets do is help preventing heat soak when the car idles or after you shut it off. A hot motor will heat up the manifolds and carbs after shutoff and can boil the gas in the float bowls. The carb version of "vapor lock". While you're running the car hard, they make no difference. But they insulate the runners from the heads, minimizing heat transfer at idle or after a run. (IMG:style_emoticons/default/shades.gif) Andy |
r_towle |
Apr 10 2009, 06:57 PM
Post
#8
|
Custom Member Group: Members Posts: 24,638 Joined: 9-January 03 From: Taxachusetts Member No.: 124 Region Association: North East States |
You need the phenolic spacer for exactly what Andy says.
They did not have them on the early 356's and they commonly suffer from boiling fuel and a form of vapor lock. Joe, if you need one, I have probably have a spacer or two around here. Dont use a broken one. Its basically thick formica (paper and resin mixed) and can be repaired with epoxy of contact cement,,,depending upon what is going on. You dont need an air leak... Either come over here and get another one, or fix the one you have so its perfectly leak free. I am around tommorow. Rich |
dbgriffith75 |
Apr 11 2009, 07:08 AM
Post
#9
|
TheGrif Group: Members Posts: 509 Joined: 25-July 07 From: Iowa, USA Member No.: 7,945 Region Association: Upper MidWest |
let the manifolds heat up to promote fuel atomization? Sounds good in theory, but that's not how it works. Carbs suck huge amounts of air through a small opening, thus dissipating a lot of heat. Ever heard of carbs "icing" up? Go for a spirited run and immediately get out and touch your carbs. They'll be very cold. The same principle is used in refrigerators to cool down the air inside. What the thick FI gaskets do is help preventing heat soak when the car idles or after you shut it off. A hot motor will heat up the manifolds and carbs after shutoff and can boil the gas in the float bowls. The carb version of "vapor lock". While you're running the car hard, they make no difference. But they insulate the runners from the heads, minimizing heat transfer at idle or after a run. (IMG:style_emoticons/default/shades.gif) Andy What if a guy was to lose the spacer between the intake and head and place one between the carb and the intake? It would probably have to be a thicker one but it would still do the job of preventing the gas from boiling in the carb, which would then, theoretically, allow the gas to atomize in the manifold, right? I only ask because this is how the carbs are mounted on some older American cars and pickups. The intakes are bolted directly to the heads and then a thick (some as thick as 1/2") spacer/gasket is placed between the intake and carb. I don't know if engineers back then planned to atomize the gas in the intake, but the spacer was there to prevent the carbs from overheating after shut off and causing vapor lock. |
r_towle |
Apr 11 2009, 07:33 AM
Post
#10
|
Custom Member Group: Members Posts: 24,638 Joined: 9-January 03 From: Taxachusetts Member No.: 124 Region Association: North East States |
let the manifolds heat up to promote fuel atomization? Sounds good in theory, but that's not how it works. Carbs suck huge amounts of air through a small opening, thus dissipating a lot of heat. Ever heard of carbs "icing" up? Go for a spirited run and immediately get out and touch your carbs. They'll be very cold. The same principle is used in refrigerators to cool down the air inside. What the thick FI gaskets do is help preventing heat soak when the car idles or after you shut it off. A hot motor will heat up the manifolds and carbs after shutoff and can boil the gas in the float bowls. The carb version of "vapor lock". While you're running the car hard, they make no difference. But they insulate the runners from the heads, minimizing heat transfer at idle or after a run. (IMG:style_emoticons/default/shades.gif) Andy What if a guy was to lose the spacer between the intake and head and place one between the carb and the intake? It would probably have to be a thicker one but it would still do the job of preventing the gas from boiling in the carb, which would then, theoretically, allow the gas to atomize in the manifold, right? I only ask because this is how the carbs are mounted on some older American cars and pickups. The intakes are bolted directly to the heads and then a thick (some as thick as 1/2") spacer/gasket is placed between the intake and carb. I don't know if engineers back then planned to atomize the gas in the intake, but the spacer was there to prevent the carbs from overheating after shut off and causing vapor lock. Try it and let us know. There are spacers for webers out there...they mount them on v8 hotrods all the time...so that spacer you are talking about is an off the shelf part. Might make it run better...hmmm Rich |
dbgriffith75 |
Apr 11 2009, 07:44 AM
Post
#11
|
TheGrif Group: Members Posts: 509 Joined: 25-July 07 From: Iowa, USA Member No.: 7,945 Region Association: Upper MidWest |
Try it and let us know. There are spacers for webers out there...they mount them on v8 hotrods all the time...so that spacer you are talking about is an off the shelf part. Might make it run better...hmmm Rich I'd love to Rich but I don't have a teener in working condition to test it out on. (IMG:style_emoticons/default/dry.gif) |
JOE M |
Apr 11 2009, 10:49 AM
Post
#12
|
Member Group: Members Posts: 293 Joined: 27-August 07 From: N.H Member No.: 8,042 Region Association: None |
I fixed the one that was cracked. I still do not have my intakes so I cant do much yet.
|
Lo-Fi Version | Time is now: 31st October 2024 - 09:27 PM |
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 ... |