PMO versus Webers, Anyone have experience? |
|
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. |
|
PMO versus Webers, Anyone have experience? |
billh1963 |
Oct 13 2013, 04:20 PM
Post
#1
|
Car Hoarder! Group: Members Posts: 3,402 Joined: 28-March 11 From: South Carolina Member No.: 12,871 Region Association: South East States |
The triple webers on my 6 have trouble staying in tune. At certain rpm's I get minor backfiring through the carbs.
At 48 years old the carb bodies are probably worn and need extensive rebuilding. At Okteenefest Bob Saville was telling me I should check out PMO carbs. Although expensive, the testimonials certainly sound good. Anyone have experience with PMO carbs? The engine is so strong I want to get everything I can out of it. |
r_towle |
Oct 13 2013, 04:31 PM
Post
#2
|
Custom Member Group: Members Posts: 24,591 Joined: 9-January 03 From: Taxachusetts Member No.: 124 Region Association: North East States |
Try calling Eurometrix about rebuilding what you have, it may be a good way to gauge the price.
|
billh1963 |
Oct 13 2013, 04:53 PM
Post
#3
|
Car Hoarder! Group: Members Posts: 3,402 Joined: 28-March 11 From: South Carolina Member No.: 12,871 Region Association: South East States |
Eurometrix full rebuild is $2340.
New PMO carbs (only) are $3400. |
Mark Henry |
Oct 13 2013, 05:00 PM
Post
#4
|
that's what I do! Group: Members Posts: 20,065 Joined: 27-December 02 From: Port Hope, Ontario Member No.: 26 Region Association: Canada |
The triple webers on my 6 have trouble staying in tune. At certain rpm's I get minor backfiring through the carbs. At 48 years old the carb bodies are probably worn and need extensive rebuilding. At Okteenefest Bob Saville was telling me I should check out PMO carbs. Although expensive, the testimonials certainly sound good. Anyone have experience with PMO carbs? The engine is so strong I want to get everything I can out of it. Your throttle shaft bushings are worn and/or your manifolds are warped. PMO's are good, but it's 6 of one, or half a dozen of the other. You can buy PMO's and flog your old Webers on the bird board or you can get your Webers rebuilt by Performance Oriented or Eurometrix. In the end each route will cost about the same. One caveat is new carbs won't help a tired engine. |
ThePaintedMan |
Oct 13 2013, 05:05 PM
Post
#5
|
Advanced Member Group: Members Posts: 3,886 Joined: 6-September 11 From: St. Petersburg, FL Member No.: 13,527 Region Association: South East States |
(IMG:style_emoticons/default/agree.gif)
There are still a lot of purists who will pay a pretty penny for original Webers, even in poor condition. You could make some money towards a new set of PMOs that you wouldn't (hopefully) have to mess with. PMOs are nothing short of beautiful. As much as I like rebuilding carbs, I really enjoy seeing really well executed designs. As hard as it is to improve on the original Weber design, the PMOs are a step up. |
carr914 |
Oct 13 2013, 05:06 PM
Post
#6
|
Racer from Birth Group: Members Posts: 119,021 Joined: 2-February 04 From: Tampa,FL Member No.: 1,623 Region Association: South East States |
|
patssle |
Oct 13 2013, 05:14 PM
Post
#7
|
Senior Member Group: Members Posts: 981 Joined: 28-August 09 From: Houston, TX Member No.: 10,741 Region Association: None |
Check out http://www.performanceoriented.com/ as well for Weber remanufacture/rebuild. I used him for a minor fix and he's a great guy to deal with - I strongly recommend him.
|
billh1963 |
Oct 13 2013, 05:22 PM
Post
#8
|
Car Hoarder! Group: Members Posts: 3,402 Joined: 28-March 11 From: South Carolina Member No.: 12,871 Region Association: South East States |
The triple webers on my 6 have trouble staying in tune. At certain rpm's I get minor backfiring through the carbs. At 48 years old the carb bodies are probably worn and need extensive rebuilding. At Okteenefest Bob Saville was telling me I should check out PMO carbs. Although expensive, the testimonials certainly sound good. Anyone have experience with PMO carbs? The engine is so strong I want to get everything I can out of it. Your throttle shaft bushings are worn and/or your manifolds are warped. PMO's are good, but it's 6 of one, or half a dozen of the other. You can buy PMO's and flog your old Webers on the bird board or you can get your Webers rebuilt by Performance Oriented or Eurometrix. In the end each route will cost about the same. One caveat is new carbs won't help a tired engine. Engine is A1 as verified by a couple long time Porsche factory mechanics. The carbs are original to the engine...(a '65 2.0 bumped to 2.2) so I'm 99% sure the carbs are the issue. I'll keep the carbs to go with the engine. I've already been offered more for the engine than I paid for the car so as early cars keep going up in price the early engines follow. So, the question is to gamble that the carbs can be rebuilt properly or make the leap to PMO's. |
carr914 |
Oct 13 2013, 05:28 PM
Post
#9
|
Racer from Birth Group: Members Posts: 119,021 Joined: 2-February 04 From: Tampa,FL Member No.: 1,623 Region Association: South East States |
Carbs can be Re-Built properly, but you are still dealing with a 40 year old Part.
When ordering PMOs, Richard Jets them to your Engine's specs, so they are basically Plug n Play |
Mark Henry |
Oct 13 2013, 05:28 PM
Post
#10
|
that's what I do! Group: Members Posts: 20,065 Joined: 27-December 02 From: Port Hope, Ontario Member No.: 26 Region Association: Canada |
The triple webers on my 6 have trouble staying in tune. At certain rpm's I get minor backfiring through the carbs. At 48 years old the carb bodies are probably worn and need extensive rebuilding. At Okteenefest Bob Saville was telling me I should check out PMO carbs. Although expensive, the testimonials certainly sound good. Anyone have experience with PMO carbs? The engine is so strong I want to get everything I can out of it. Your throttle shaft bushings are worn and/or your manifolds are warped. PMO's are good, but it's 6 of one, or half a dozen of the other. You can buy PMO's and flog your old Webers on the bird board or you can get your Webers rebuilt by Performance Oriented or Eurometrix. In the end each route will cost about the same. One caveat is new carbs won't help a tired engine. Engine is A1 as verified by a couple long time Porsche factory mechanics. The carbs are original to the engine...(a '65 2.0 bumped to 2.2) so I'm 99% sure the carbs are the issue. I'll keep the carbs to go with the engine. I've already been offered more for the engine than I paid for the car so as early cars keep going up in price the early engines follow. So, the question is to gamble that the carbs can be rebuilt properly or make the leap to PMO's. Since it's an early engine personally I'd go with the full meal deal rebuild of the Webers from Performance Oriented. |
billh1963 |
Oct 13 2013, 06:24 PM
Post
#11
|
Car Hoarder! Group: Members Posts: 3,402 Joined: 28-March 11 From: South Carolina Member No.: 12,871 Region Association: South East States |
Looks like I have some thinking to do!
Thanks everyone for your replies. |
Eric_Shea |
Oct 13 2013, 11:35 PM
Post
#12
|
PMB Performance Group: Admin Posts: 19,278 Joined: 3-September 03 From: Salt Lake City, UT Member No.: 1,110 Region Association: Rocky Mountains |
Paul at Performance Oriented is a Meistro.
Not sure how someone can tell your bushings are worn (Mark) without looking at them (IMG:style_emoticons/default/biggrin.gif) What your describing are running issues that might be cause by shaft bushings but I'd make sure the items on performanceoriented.com are followed for tuning. It starts with a valve job. Then follow his lean best method to tune. They probably need to be rebuilt. You can clean and get new gaskets in them yourself. If there are worn shaft issues you can see them as carbon traces on the butterflies when you turn them upside down. If you check out Paul's site you can see the amazing work he does. I spent a couple months with mine. Here's some recommendations: 1. Valve job 2. Get the proper syncrometer. 3. Rebuild the carbs 4. Find out everything you can about your jets and emulsion tubes. 5. Have the peak rpm of your cam on hand 6. Make sure you have the proper jets. 7. Make sure the emulsion tubes match the cams. 8. Make sure you have 3.5lbs of fuel pressure at the carbs. 9. Follow all Paul's tuning guidelines, especially the linkage adjustment procedure. Even if the shafts are worn, that should get you running 100% better. |
Mark Henry |
Oct 14 2013, 05:47 AM
Post
#13
|
that's what I do! Group: Members Posts: 20,065 Joined: 27-December 02 From: Port Hope, Ontario Member No.: 26 Region Association: Canada |
Not sure how someone can tell your bushings are worn (Mark) without looking at them (IMG:style_emoticons/default/biggrin.gif) If he posts a pic of the throttle plates I most likely could and checking the thrust wear can be done in the car. Worn shafts is common issue in webers (and stock TB's and VW carbs and IDF webers and etc....), I've re-bushed more than a few sets over the years. |
ThePaintedMan |
Oct 14 2013, 06:05 AM
Post
#14
|
Advanced Member Group: Members Posts: 3,886 Joined: 6-September 11 From: St. Petersburg, FL Member No.: 13,527 Region Association: South East States |
Slight hijack - Mark, I've always been curious, how are the bores bushed? I have a pair of Webers that have been and it looks like a total PITA, particularly on the inner bores.
Also, the IDFs never had bushings from the factory, correct? The body of the carb itself was drilled to close enough tolerances that they deemed bushings unnecessary. So any carbs with brass bushings have had the bores drilled out, the plugs inserted (somehow) and then redrilled? |
carr914 |
Oct 14 2013, 06:19 AM
Post
#15
|
Racer from Birth Group: Members Posts: 119,021 Joined: 2-February 04 From: Tampa,FL Member No.: 1,623 Region Association: South East States |
|
Mark Henry |
Oct 14 2013, 06:58 AM
Post
#16
|
that's what I do! Group: Members Posts: 20,065 Joined: 27-December 02 From: Port Hope, Ontario Member No.: 26 Region Association: Canada |
Slight hijack - Mark, I've always been curious, how are the bores bushed? I have a pair of Webers that have been and it looks like a total PITA, particularly on the inner bores. Also, the IDFs never had bushings from the factory, correct? The body of the carb itself was drilled to close enough tolerances that they deemed bushings unnecessary. So any carbs with brass bushings have had the bores drilled out, the plugs inserted (somehow) and then redrilled? The throttle shaft? I've always made custom bushings with about a .0005 press fit, install and ream to size. Some have bearings, the thrust wears out on them from incorrect linkage geometry. Real PITA job because every thing is so tiny and the housings don't take much to crack. |
carr914 |
Oct 14 2013, 08:55 AM
Post
#17
|
Racer from Birth Group: Members Posts: 119,021 Joined: 2-February 04 From: Tampa,FL Member No.: 1,623 Region Association: South East States |
[quote name='carr914' date='Oct 13 2013, 07:28 PM' post='1940128']
Carbs can be Re-Built properly, but you are still dealing with a 40 year old Part. [/quote] [quote name='Mark Henry' date='Oct 14 2013, 08:58 AM' post='1940340'] [quote name='ThePaintedMan' post='1940310' date='Oct 14 2013, 08:05 AM'] the housings don't take much to crack. [/quote] Exactly! |
Lo-Fi Version | Time is now: 10th June 2024 - 04:18 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 ... |