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 )

> Newbie Question 2: Weber Carburetors
amfab
post Jul 28 2016, 02:24 PM
Post #1


Member
**

Group: Members
Posts: 393
Joined: 17-May 16
From: Los Angeles
Member No.: 20,004
Region Association: None



I just bought a 74 2.0. Previous owner says previous owner rebuilt it out to 2.1 a few years ago but there is no documentation. Regardless, it IS a GA with 3 bolt intakes so I will assume at least 42mm intake valves.

It came with dual Weber 36idfs with 32 venturis.

The motor seems a bit anemic at the higher RPM. To me—quite an amateur at this kind of stuff—it kind of makes sense because the throttle bodies seem a bit small for the motor (it seems that a lot of the type 1 guys use 36idfs on sub-2 litre motors).
I just had the car tuned up and it runs very nicely, but not a lot of power and it flattens out fast above 4kRPM

I considered megasquirt, but because I have linkage and manifolds I was thinking going the easier and cheaper route of 40 or 44 idfs.

After doing a bit of research, my thoughts are either 40idfs with 34 venturis or 44idfs with 36 venturis. Just a little more oomph will be able to carry me until I eventually do a six conversion in a couple years. Are 44idfs too much carb for the 2.0 (or possible 2.1)?

Unfortunately, there is no documentation on the cam either. I (and my mechanic) are thinking its stock or close to it.

Any advice would be greatly appreciated.

Thank you

-Andrew
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
 
Reply to this topicStart new topic
Replies
colingreene
post Jul 28 2016, 11:38 PM
Post #2


Senior Member
***

Group: Members
Posts: 729
Joined: 17-October 13
From: Southern California
Member No.: 16,526
Region Association: Southern California



sounds like the cam is more your problem than anything else.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
porschetub
post Jul 29 2016, 02:02 AM
Post #3


Advanced Member
****

Group: Members
Posts: 4,706
Joined: 25-July 15
From: New Zealand
Member No.: 18,995
Region Association: None



QUOTE(colingreene @ Jul 29 2016, 05:38 PM) *

sounds like the cam is more your problem than anything else.


36 IDFs should be ok ,you could be suffering a lean condition @ high rpm,take it for a good hard run and check your plug colour,it should be a rich brown .
Remember that it isn't the throat size of the carbs it is the venturi size that dictates the power,you could go to say 34 vents and end up with better performance over the power range than say 40 or 44's can provide as you will lose some of the lower end power that you drive in most of the time.
Is your ignition really and truly up to the mark ,for instance is the distributor advancing totally at higher rpm,all these factors come in to play,tell us more and that will really help cause you should still be making power @ higher rpm regardless of the cam .
Many members can help you on here,cheers

EDIT....don't wait too long for six conversion otherwise you will be struggling to find a motor for a decent price.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
amfab
post Jul 30 2016, 04:26 PM
Post #4


Member
**

Group: Members
Posts: 393
Joined: 17-May 16
From: Los Angeles
Member No.: 20,004
Region Association: None



QUOTE(porschetub @ Jul 29 2016, 01:02 AM) *


...you could go to say 34 vents and end up with better performance over the power range than say 40 or 44's can provide as you will lose some of the lower end power that you drive in most of the time...


I considered the 34 vents as an option. You are saying that too much throttle body could hurt low end?
I mean if I go to 34s iwith 36dfs I could have more low end than 40idfs with 34 venturies?

Im thinking about getting a weber bookl to learn more about all of this. Thank you for the help.

Also, yes, I am fully aware of how fast everything air cooled seems to be rising dramatically in price.
The reason I jumped into the 914 now is because I had been talking about getting a 914 for years and when I saw how the 911s have gone up in the last 10, I thought I should get in to the 914 pretty quick

Also, I agree Collin, ultimately if it is a stock cam, changing that would give me the most oomph, Its just that right now it runs nicely, doesn't leak, and I don't wanna tear it down right now (I just dropped a bunch on rebuilding my 993). Im just trying to squeeze a few more HP oouta what I have now.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post

Posts in this topic


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

 



- Lo-Fi Version Time is now: 8th June 2024 - 07:44 PM