68 912 timing???

gregk1 · 04:24 PM

i am working on a 68 912 and i have had the timing all over up and down 5% 10% TDC and points set at 16k it still pings and rattles. it has sat and has not been drivin much in the last 6 years two years since it ran last. carbs seem to run ok and respond to the air jets took the tops off and cleaned the tubes in the center small hesitation mid range new 92 fuel any ideas???? i am 911 guy mostly but have had a few 912s but none of
them ran this one does??? thanks greg (ps webber carbs)

Flieger · Flieger's Garage

Are the spark plugs factory spec or did a PO put in hotter platinums?

gregk1 · 09-10-2008, 06:41 AM

they looked standerd not platinums it is also running real hot i am not sure if the temp gauge is working but it was past the red yesterday will check the temp with my lazer temp gun i think i need to see if there is any vermin nests in the cooling system there was one in the glove box

WFBowen · WFBowen's Garage

Double check:
Valve adjustment.
Test for any major vacuum leaks.
Compression test.
Check that carbs are absolutely clean and proper float level.
Did you own/drive this car when it ran well?

356racing · 09-10-2008, 09:22 AM

In addition to what WFBowen said...
What distributor are you running?

You need a timing gun to see what the timing is at full advance, if it's ping'n I bet it's up there or the carbs are not working properly.

Flieger · Flieger's Garage

I also agree with those who say check the distributor timing. Retarded timing can cause high cylinder head temperatures,

gregk1 · 06:28 AM

i just am helping a gal out that bought this car in 2002 and has not driven much since then every one was telling her it is a pice of junk and get rid of it but on a scale of 1 to 10 it is an easy 8 + oone of the most complete 912'si have seen the temp wire was un plugd so it may not have been s hot as i thought i will check the dizzy today and will go theu the valves i had my light on it and the advance is moving i am going to try the old VW timing trick with #1 plug satic and see what i get the carbs seem to work well it idel is good and it responds on all four air bleed screws i took the tops off and checked the float levels and the floats looked nice and level the main let and emulstion tubes are clean i will look at plugs and see how they look Thanks for all of your input i want to prove to all the non porsche people that called it a junker and the motor is shot Bla Bla Bla!!!

Jaems · 09:42 AM

The 68's had the 061 type distributor which is vacuum retarded. If she still has this one installed. The Vacuum retard needs to be disengaged before you try to set the timing. Which I assume you know by now is 30-35 degrees at 3100 rpms.
The static is done only in emergencies at 3 - 4 degrees BTDC.
The dwell is 50 degrees + or - 3 degrees.
The points are set at 0.4mm and the plugs are 0.6 - 0.7 mm.
The valves are set: Exhaust at 0.15 mm and the Intake at 0.10 mm.

The Webers are probably set up for VW's. They usually were when they were first purchased. Unless the PO changed them the venturis should be 32. If they are 28 then the Webers are still setup for VW's. The jets, airs, and etc. would depend at what altitude you are at. I don't remember where Auburn is in Washington. However, if you go to the 912BBS and search the archives. There has been extensive posting on Webers the jets, air and etc. Once they are setup correctly for the 912. They are excellent carburettor for then 912.

gregk1 · 09-13-2008, 07:00 AM

it does not have a vaccum dizzy i thought i saw a 009?? i will double check it pops on #2 thru the carb i set the timing at around 35 at 4000 range seem down on power makes some noise when cold but quiets down when warm (forged pistons?) would pinging be a lean condtion??? if the carbs ar setup for vw??? the temp is good less than half way on the guage

gregk1 · 09-13-2008, 07:20 PM

well opon ferther inspection it has 115 main 28 venturi's tubes are F11????sounds like VW set up ???? where can i get the parts ?? thanks >>>Greg

Jaems · 09-13-2008, 08:42 PM

The 009 is the worst distributor for a street 912, next is the 050. The 009 is only good at high RPMS. That is why it is used for racing 912's. Where they keep the RPMS above 5000. You really want a 022, 031, 061, or the RS00012 that is a 009 that has been recurved for a 912 street engine.

The 022 came originally on the early 912s. In 68 they went to the 061 which is a 031 with vacuum retard. The best distributor is the 031 which there are three types. The newest or type three you do not want only types 1 and 2. The next best is the RS00012 which is much cheaper than the 031, 061 or the 022.

You will have no power to speak of at lower to mid range with 009.

It's been a while since I had to play with my Webers. I think it would be closer to 125-130 and f7 or f11 it depends on your altitude. My engine pulls strong from 2500 on even in 5th. If the cam is not flat and the valves burnt. Then it is just the matter of correct jetting, airs and etc and the correct distributor. oh, and 32 venturis. Parts are from PMS or something like that. I haven't purchase any parts for my Webers in over ten years. You might Google it.

If she has forged pistons. It should sound like a diesel or a rods knocking. Mine always have.

C. Clark · C. Clark's Garage

Popping generally means lean mixtures, at lest in my experiences, but when diagnosing a full tune is in order, setting the valves, timing, points, if you have them, and carburetors. Weber parts are here, http://www.weberpartsdirect.com/ and I imagine www.classicandspeedparts.com/ has pieces also. I run a RS00012 on my 912 and compared to the .050 works very well, return to idle being the most prominent improvement, at least in my case.
Happy hunting,
Chas.
356912911

gregk1 · 09-14-2008, 08:01 AM

it does sound like a diesel untill it warms up. so is this a hot ro 912 engine?? the valve springs are the size of a big block chevy?? it is verry dead on power like you say. do you know anyone that will trade a 009 dizzy for a 031 or somthing more streetable the car will be driven at sea level she lives in ocean park wa 1/8 of a mile from the beach. could i get away with 130 main and the f11 tubes and 32 venturis?? thanks for all your input it realy helps >>>>>Greg

Jaems · 08:54 PM

Sorry, no one is going to trade a 009 for a 031. They will run about $500 rebuilt or more. Unless someone doesn't know what they have. You might try Will at Classic and Speed Parts. He sell the RS00012 which should be great for her car. His number is 1.626.445.0108 The RS00012 would be the cheapest way to go also. Less than $200 the last I heard.

I will have to ask the engine builder that help me build my engine. To see if he can remember what I have in the Webers. It should be pretty close to what she would need at sea level might need some minor tweaking.

Having forged pistons does not necessarily mean she has a hot rod. They were cheaper than the original and the Japanese big bore were out of production. The ones being the replacements for the big bore kit where not very good. So at the time the best way to go was probably the Shasta Forged pistons kit. The kit came in two different compression ratios the stock one and the 11:1. However, if she has the 11:1 then that could also be the one of the reasons for the pinging and also for the 009. The 009 would not be very good for the street. But good for high RPMS on the track with it's short advance curve. She could then also have a cam. This is all speculation I am only going on what you have be posting and the possibility that the engine was being set up for track days.

However, I would go with the RS00012 it has a very nice curve for the 912. Also I would be running premium fuel. As some as I can find or figure out what I am using in the Webers. I will post it here. I posted it once about 4 years back on the 912 BBS.

Jaems · 09-14-2008, 08:54 PM

I found this on the 912 search.

"Mark, you might check your emulsion tubes, the part the main jet goes into. They should be F7. venturis of 32mm dia.,125-130 main jets 180 air correction jets,and 55 idle jets. Also remove and blow through idle jets they often plug up on the webbers causing rough running engine. I found that the main jet size and the emulsion tubes made the biggest difference in engine performance and smooth operation."

If this isn't what I am using it is very close. Also unless you are going racing get rid of any stacks that might be on the Weber carburetors. They are all wrong for a street 912. The engine will be smoother and you will get better gas mileage. Like the 009 the stacks are only good in the upper rpm ranges.

Jaems · 09-15-2008, 08:47 AM

I am assuming that you know how to sinc in the Webers. In case someone else wants to try it.

I first remove the linkage to the carbs. Turn the adjustment screws in and then turn them out about 1.5 to 2 turns. Then sinc in the carbs by take one barrel and adjust the others to that one. Then I set the idle. Then recheck the sinc on the carbs. When everything is OK. Then adjust the linkage to the carbs and attach the linkage. Then I will check the sinc again.

I also used the gauge for Webers, not the Unisinc. It was fine when I drove those Brit cars back in the late 50's and early 60'.

gregk1 · 09-15-2008, 09:12 AM

carbs unlimited has some parts and he said i could try the 130 main with the( f11??) tubes and a 30 venturi's parts are not cheep and just need to get this thing to be a driver there is NOTHING! on the bottom off idle to 2500 i have to damm neer rapp it and drop the clutch to get it going but then it is not to bad and yes i have done the sinc thing on my 911's and have sinc'd the 912 still runs like POO i need the dizzy and some jetting before i pull what little hair i have left out of my head >>>>>>>thanks agen for every thing Greg

gregk1 · 09-15-2008, 05:31 PM

well tried 55 idle and 125 main ran like $hit went back to 50 idle and 115 main and runs alot better power wise and at idle snezzes real bad on aft right cylnder no mater what i do it will not stop it also did it before i ajusted the valve lash and they were verry loose my friend says put a pertronics igniter in and get rid of the points?????

Jaems · 09-15-2008, 09:18 PM

The main problem is the 009. It will not help messing with the carbs. Until you replace that distributor.

This is the graph the was made with the different Distributors. The 009 is the one on the right in what is black. Putting in pointless electronics is not going to help the lower in torque. If you are going to keep the 009. Then teach her to leave the stop sign or lights at 2500+ and leave it in a lower gear to keep the rpms up. Kind of like driving an old 70 911S light weight.

The 009 was designed for a VW and Type 4 engines not for a 912.

gregk1 · 09-16-2008, 07:04 AM

well that is exactly the way it runs on the 009 graf i guess i will get the rs0002 most of the shop pro's say to throw the webbers in the scrap heap and get the solexes back one gu said he wound't work on a 912 if it has webbers on it i tend to beleve him for what i have been theu to get this thing to run what a sneezzn poping little basterd i will look in to the dizzy hope i get more out of it than the money i spent on jetting