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914World.com _ 914World Garage _ Carb tuning questions
Posted by: KaptKaos Oct 29 2007, 12:19 AM
I am getting close to firing up my new motor. It's a 1911 with unknown cam (not stock). I have weber 44 idfs on there. The venturis don't have any marking as to their size. I have the other numbers for the mains, idles, air, & emulsion written down somewhere.
Now I know it's hard to predict what the best combination will be, but I want to see if anyone has experience with a similar setup to see what they were running. I will need to by additional bits for tuning, and I hope to minimize that as best I can.
Thanks in advance.
Posted by: Twystd1 Oct 29 2007, 01:34 AM
Joe,
Break out a measuring tool and find out what vents you have. And I hope they are 32s.
Cause thats what you probably need. 34s, 36s or 38s are gunna be too big.
NOTE: If this is a new engine. And not a used engine. Use a KNOWN good set of carbs to break in your engine if you can.
Caveat: Unless you are pretty dam sure your carbs are in good working order and AREN'T over jetted.
Why you may ask...???????????????????????????????????
Cause if you break in a new engine and your carbs are running very rich....... Your rings won't seal. The fuel will wash the oil off the cylinder walls and rings and they don't seat.... EVER.
OR: You might be taking your top end off and re-ringing the pistons and re-honing your cylinders. (Just ask MattR)
I have seen 4 cases of that right here in our 914 arena. And the fellas couldn't understand why a new engine smoked and consumed oil like a fat lady at a Crispy Creams shop. (Or Aaron.... same difference)
At least post your jet sizes, Emulsion tube and venturi sizes here BEFORE you fire that engine up....!!!!!!!!!!!
(This assumes it's a never been fired engine)
Call me if ya need me..... 949.944.082one
Claytonobitch
Now whats your name again...???? Fred...???????
Posted by: KaptKaos Oct 29 2007, 03:55 AM
Thanks Clayton,
It's Grimstead's old motor, so I think its done broke in already. I thought Aaron had sent me the jets and emulsion tube sizes, but I can't seem to find them atm. I'll keep lookin'.
Posted by: Joe Ricard Oct 29 2007, 06:01 AM
How do you know if a Carb works????
Bowls fill with fuel and stop when full. (GOOD)
acceleration jets squirt when throttle is opened (good)
Carb cleaner sprayed in idle jet hole and comes out progression ports. (really good)
carb cleaner down main jet stak and it comes out the secondary vent holes. Good as it gets.
Standard 50 or 55 idles shouls be all you need.
135 mains is a middle ground with 180 air.
after that you are on your own.
Posted by: rhodyguy Oct 29 2007, 07:59 AM
read my recent 40idf issue thread. go to the mharney site clayton provided and read all the proceedures and tech notes until you fully understand them. for clarity and simplicity, his writeups are the best i've seen. get the lowdown on your new carbs. ask the previous carb owner alot of ?s regarding any symtoms the carbs might have exibited.
k
Posted by: rhodyguy Oct 29 2007, 08:02 AM
read my recent 40idf issue thread. go to the mharney site clayton provided and read all the proceedures and tech notes until you fully understand them. for clarity and simplicity, his writeups are the best i've seen. get the lowdown on your new carbs. ask the previous carb owner alot of ?s regarding any symtoms the carbs might have exibited.
k
Posted by: geniusanthony Oct 29 2007, 09:03 AM
How does one know if they're rings have seated on a new engine...?
can't test just curious for general purpose
Posted by: Joe Ricard Oct 29 2007, 10:28 AM
Leak down.
Posted by: cooltimes Oct 29 2007, 03:10 PM
I am getting close to firing up my new motor. It's a 1911 with unknown cam (not stock). I have weber 44 idfs on there. The venturis don't have any marking as to their size. I have the other numbers for the mains, idles, air, & emulsion written down somewhere.
Now I know it's hard to predict what the best combination will be, but I want to see if anyone has experience with a similar setup to see what they were running. I will need to by additional bits for tuning, and I hope to minimize that as best I can.
Thanks in advance.
http://www.carburetorclinic.com/tech_articles.htm
40IDF .
Might be exactly what you are asking about.
Posted by: KaptKaos Nov 1 2007, 11:06 PM
Got some stats:
emulsion tubes F11
Air Correction 190
Mains 145
Venturis 32
idles 0.5
I am going to try and source 28 vents. Any other recommendations?!?!?
Posted by: Aaron Cox Nov 1 2007, 11:20 PM
do they even make 28 vents for 44's? i dont think they do....
Posted by: KaptKaos Nov 1 2007, 11:34 PM
do they even make 28 vents for 44's? i dont think they do....
Hmmm..... looking for that now.....
You know what carbs Grimstead was running?
Posted by: Twystd1 Nov 1 2007, 11:39 PM
OOOPs...
32s is the smallest for da 44.
Clayton
Posted by: KaptKaos Nov 1 2007, 11:45 PM
OOOPs...
32s is the smallest for da 44.
Clayton
Ok, so what should I do? Run them with the 1911 or look for 40s? I think Bill was running 44s with the motor before I got it. Not sure of the rest of his settings (air, mains, idles, etc..).
Thoughts?
Posted by: Twystd1 Nov 2 2007, 02:38 PM
The problem for me is that you have an unknown cam. And I have no idea what your static compression ratio is. (which to some degree is relevant)
Jake has stated several times that he can make 44s work on smaller engines.
I personally have had no luck on making 44s work on any kind of stock 2.0 liter engines.
Then again. If this is a high revvvver. 44s might be exactly what you need.
I have no clue to what this engine combo is set up for.
Fuck it. Run em. Lets see what happens. get some 32 vents, keep your F11 tubes. Jet it as per Mark, He seems to know a good ball park setting. And see what you get.
The worst that will happen is we find ya a swap for 40s. That shouldn't be too hard.
DO NOT LET THIS ENGINE RUN SUPER RICH. If that happens. re-jet it.
(Or lean for that matter)
And remember what I told you. Bigger air correctors make it run richer. (The opposite of what your intuition tells you.)
Cheers,
Clayton
Posted by: gjones Jan 20 2008, 11:08 AM
Joe,
Break out a measuring tool and find out what vents you have. And I hope they are 32s.
Cause thats what you probably need. 34s, 36s or 38s are gunna be too big.
NOTE: If this is a new engine. And not a used engine. Use a KNOWN good set of carbs to break in your engine if you can.
Caveat: Unless you are pretty dam sure your carbs are in good working order and AREN'T over jetted.
Why you may ask...???????????????????????????????????
Cause if you break in a new engine and your carbs are running very rich....... Your rings won't seal. The fuel will wash the oil off the cylinder walls and rings and they don't seat.... EVER.
OR: You might be taking your top end off and re-ringing the pistons and re-honing your cylinders. (Just ask MattR)
I have seen 4 cases of that right here in our 914 arena. And the fellas couldn't understand why a new engine smoked and consumed oil like a fat lady at a Crispy Creams shop. (Or Aaron.... same difference)
At least post your jet sizes, Emulsion tube and venturi sizes here BEFORE you fire that engine up....!!!!!!!!!!!
(This assumes it's a never been fired engine)
Call me if ya need me..... 949.944.082one
Claytonobitch
Now whats your name again...???? Fred...???????
Let's say someone did this and has now resolved the rich issue- should this person pull the heads at this point or see if they might seal. Also have you had good luck with 44 IDF's ran with 32 venturis- this person does not have plans on going bigger on the engine- but does run at the track occsionally- willing trade trade out the 44's for 40's if necessary.
Posted by: gjones Jan 20 2008, 11:17 AM
The problem for me is that you have an unknown cam. And I have no idea what your static compression ratio is. (which to some degree is relevant)
Jake has stated several times that he can make 44s work on smaller engines.
I personally have had no luck on making 44s work on any kind of stock 2.0 liter engines.
Then again. If this is a high revvvver. 44s might be exactly what you need.
I have no clue to what this engine combo is set up for.
Fuck it. Run em. Lets see what happens. get some 32 vents, keep your F11 tubes. Jet it as per Mark, He seems to know a good ball park setting. And see what you get.
The worst that will happen is we find ya a swap for 40s. That shouldn't be too hard.
DO NOT LET THIS ENGINE RUN SUPER RICH. If that happens. re-jet it.
(Or lean for that matter)
And remember what I told you. Bigger air correctors make it run richer. (The opposite of what your intuition tells you.)
Cheers,
Clayton
Used to live in Newport in the 70's- spent alot of time at Perry's Pizza and Charlie's Chili. Would you go 180 or 200 correction tubes for a mild cam 2 liter with 44's- everything else jetted/ran to the above numbers? Thank for your input.
Posted by: degreeoff Jan 20 2008, 12:32 PM
All you need and more for weber tuning....
http://members.rennlist.com/webercarbs/
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