I am trying to locate what the ignition timing should be set at on a Gene Berg built engine from a CMC factory built speedster built in 1983. I know the cam was not standard and the engine beefed up. Including dual Weber 40idf carbs. Any help would be appreciated.
renfrance
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Rev the engine to 3000 RPM, leave it there, and check the timing. You should have about 28 deg of advance at that point. Wherever your timing ends up at idle is OK.
It really depends on what your engine is set up as. In the aircooled world,there seems to be the hardcore tuning types that install a SVDA with a vacuum diaphragm on the distributor so you have higher advance at light throttle which helps with exhaust temperature and allows one to run leaner air/fuel ratios while cruising light throttle/light load while still giving a good mechanical advance for max power under high load/WOT conditions,the other 99% just have the good ole' 009.
I will ASSUME you have the 009,these are "OK" but their biggest fault is they were designed for a "stationary" engine and have a advance curve that comes in really late (for a VW engine)with max advance in teh 3200+rpm range.
If you are running good gas and you have a decently mid-range compression ratio jsut set it to the generic 7-10 deg. BTDC at idle (I say this since not all 009's are the same)and it is more important to actually see what MAX timing is. Yo will want max advance to be 28 deg.,you can run it up to 30-32 if you are running a extrememly low compression enegine or you have high octane fuel,however the power difference between 28-30 deg. BTDC is not so much ,but the 28 deg. is still more conservative/safe.
I have a 8:1 compression motor putting out 140 hp,and run 92 octane and 30 deg. BTDC.,however since I did not like the lack of low end grunt,I modified my 009 advance spring so it has less tension and now I have full advance all in by 2400 rpm,this really helped bring in the low end tq. and the engine has a much better powerband than the "regular" 009.
If yu are unsure about yur abilities,stick with the standrd settings,however if you have the skills,you can adjust the 009 to give better than usual performance.
Sounds good! I learn something new every time I visit this site!
Some, if perhaps not all, Berg engines have low compression and semi-hemi modified heads.
Gene himself told me to run either 33 or 35 degrees advance. My compression ratio is about 7:1.
It really depends on what your engine is set up as. In the aircooled world,there seems to be the hardcore tuning types that install a SVDA with a vacuum diaphragm on the distributor so you have higher advance at light throttle which helps with exhaust temperature and allows one to run leaner air/fuel ratios while cruising light throttle/light load while still giving a good mechanical advance for max power under high load/WOT conditions,the other 99% just have the good ole' 009.
I will ASSUME you have the 009,these are "OK" but their biggest fault is they were designed for a "stationary" engine and have a advance curve that comes in really late (for a VW engine)with max advance in teh 3200+rpm range.
If you are running good gas and you have a decently mid-range compression ratio jsut set it to the generic 7-10 deg. BTDC at idle (I say this since not all 009's are the same)and it is more important to actually see what MAX timing is. Yo will want max advance to be 28 deg.,you can run it up to 30-32 if you are running a extrememly low compression enegine or you have high octane fuel,however the power difference between 28-30 deg. BTDC is not so much ,but the 28 deg. is still more conservative/safe.
I have a 8:1 compression motor putting out 140 hp,and run 92 octane and 30 deg. BTDC.,however since I did not like the lack of low end grunt,I modified my 009 advance spring so it has less tension and now I have full advance all in by 2400 rpm,this really helped bring in the low end tq. and the engine has a much better powerband than the "regular" 009.
If yu are unsure about yur abilities,stick with the standrd settings,however if you have the skills,you can adjust the 009 to give better than usual performance.
James Bond Silver,
For more "low end grunt" with a better power band you "modified" the 009 advance spring to obtain full advance by 2400rpm
Exactly how was the spring modified?
Inquiring minds want to know.
Hello Carl,it is VERY easy...
I have mentioned this in Samba posts but nevber really got feedback,so maybe you may want to give it a go....
The 009 is a VERY SIMPLE distributor. It has only ONE advance spring and "max advance" is actually controlled by a metal tab that limits the advance weights movement,so even if you modify the spring,you will not get any more max advance and harm the engine since you are not touching the metal tab which regulates this. I did a very simple experiment by carefully stretching one end of the springs loop slightly and checked with a timing gun and watching my tach to see when the max advance came in. I set mine up to come in at around 23-2400 rpm,and it really gives the car more pep/tq. and you can feel it when accelerating.
This experiment came around when I was tinkering with my 1971 Westfalia and wanted more bottm end grunt without resorting to a SVDA since I had dual Kadrons and tehse do not have a vacuum take-off for diaphragm style distributors. The bus really needs tq.,and since the rpm limit is 4500 rpm,max advance coming in at 3200 rpm leaves you a very short powerband.
I stretched the spring and the bus was transformed....I lost a noticable flat spot and the tq. below 3K was nioght and day,I set that one to have full advance by 2200 rpms,and it really runs like a gem.
Remember that you need to have the carbs dialed in and everything else in check to have good results from this,and you need to have a compression ratio & quality of gas that will tolerate more advance early or you may get some "pinking". I have suffered no detrimental effects of this modification,all it did was give me a wider powerband. If you try this,get back to us and tell us how it works for you!
JamesbondSilver- Great info! What are the cams, heads and compression ratios in the motors you've done this on?
My bus has a stock,Mexican 1600 long block with properly setup dual Kadrons and a EMPI single muffler header/extractor exhaust,I got the car this way and it runs great,and has very good drivability after much time spent tuning the carbs and fiddling with timing.
My other car is a 2110/dual 44's/A-1 stinger/8.5:1/Web-Cam218/CNC ported heads/not sure of teh hed specs,but I am thinking they are for street/strip. Engine dynoed @ 136HP t only 5K rpms,and I rev it past that so gott be inthe 140HP+ club
JB Silver,
"VERY easy"? Since you emphasized very in caps I'll give it a try, and hope that all my winter wrenching and tinkering is VERY easy!!
Constuction started today to prepare my speedster's hibernation space. I'm excavating under the deck so I can easily wire in electricity from the house. I'm enclosing that space and having a baby butt smooth concrete slab poured. Hurrah! A temporary 60,000 btu Reddy-Heater kerosene blower should allow me to tinker on all but the bitterist cold weather...I've got a project list as long as my arm, and your 009 modification is on it.
Now if Rich Drewek will only design a clever and inexpensive scissor lift for me I'll be happier this winter than a pig in a mud bath. (Merklin, if your lift should wind up missing don't be alarmed...I promise to return it to you at Carlisle)
Right on Carl...this sounds like the makings of a great man-cave. It is really nice to have a place to work on your car and chill. Don't forget the workbench/sounds/good lighting/atleast one beer poster/atleast one boobie poster/mini-fridge.....this helps get the job done.
You want ME to design you a clever and inexpensive scissor lift? How did I become your savior for such a contraption? You do realize how dumb I am don't you?
