L20B Timing; Miss down low, Raped ape up high.

[JWJohnson]

Yeah it looks exactly like that...

On a side note... IT'S ALIVE MWUAHAHAHAHAHAHA runs pretty damn good if I say so myself.

 

It was my EGR delete plate leak that was the problem the whole time. So I put some Permatex on it and tightened everything down a little more. I let it sit over night. Now me and the woman just got back from a nice smooth drive in it. Ran pretty good, but I still need to put a light on it and re-time the dizzy now that the leak isn't there anymore, I think it is a little off from timing it with the vacuum leak and then adjusting it after everything was hooked back up, give it a once over again and then call it a day.

[JWJohnson]

Dat soon is asking if you line the cam sprocket back up correctly?  the  v  back of the sprocket is lined up to the dash on cam tower? at TDC. like off a tooth on timming chain.

 

5deg adv or retard? how you know? You use a degree wheel. Stock sprockts are 0, 4 and 8 deg pos 1 2 and 3 accordingly.

 

for mis also ck the valve lash correct.

I was basing the 5* off of the crank pulley with the v notch and hash mark lined up perfectly, not off to the side a little bit like in Mike's pic. If you look at the crank pulley timing marks with the v notch lined up on the horizontal hash mark like in the pic, the crank pulley reads right about 5* advanced.

 

So theoretically it would have actually been 2.5* advance as the 2:1 sprocket ratio between the crank and cam.

 

I used the #2 hole....

[datzenmike]

#2 hole is the factory setting for the L20B. A race engine may be sensitive to 2 or 3 degrees of cam but the stock L20B is, as I said, directly below the mark or just like the picture. The horizontal line is worth 4 degrees of cam so half that. 

[KlassicMotion]

Klassic motion...is that a fuel regulator that goes to carb inlet?  If so what type and what you think about it?  thx, RacerX

Yes, fuel regulator.  The Weber downdraft is sensitive to 2.5-3.5 psi.  I just bought this one off the "hot rod" section at O'Rielly's.  I had one on my Opel GT, it seemed to work well.  I need to hook a fuel pressure gauge in-line after it to see how accurate it is.  I'm in the process of moving this week, so the car is on hold.  I will be in Limbo until around May 1st, but the car will be at a shipping depot until they find a truck headed to Alaska.  So who knows when I will get the car back and able to fiddle with that.....

[racerx]

if that's the Mr. Gasket version or similar, be careful they tend to leak..hadone on my 75 Celica and was not impressed, did some asking and googling and found lots of unhappy customers...Yeh, know about weber's need for volume and not too much pressure.  Mine (32/26) is at 6 psi..tested with 2 different gauges just to be sure.  Probably later on I will get the holey 12-804 one.  This is low pressure type.  I think up to 4 psi only.

[JWJohnson]

So the #2 slot is advanced 4* correct? And you figure half the horizontal line is roughly 2* so a total of 6* technically? So my assumption about the crank pulley being used to figure about how far advanced or retard the cam is isn't too far off. If you tak into account the position I the v notch to the horizontal line. I said that the cam was 5*, with this 'guess' I was only off by 1*

[banzai510(hainz)]

you line up ther crank to Zero then look at the top sprocket. If V is to the left of the dash then that most likely is your proplem. I think more like 2 teeth would be more obvios.

I have set them off a tooth and didnt really notice a huge differnce myself. But its ez to ck . and reset.

[JWJohnson]

Yeah the cam is set up right. The truck runs good now, it was just my EGR delete plate I built, had a bad vacuum leak but I got that taken care of now and she runs like a top. I was just stating about the degreeing of a cam while using the crank pulley/Degree plate to figure how far advanced or retarded the cam was... Basically a poor mans degree wheel to get a rough estimate at where the cam was sitting in relation to TDC.

 

Horizontal line length= 4* overall from left to right

#2 hole in cam sprocket=4* advanced

 

If the left most side of the v notch were inline with the right most side of the horizontal line, it would be safe to assume that the cam is 4* degree's advanced BTDC and one could corrilate that with the degree plate on the crank pulley. You have to take into account the 2:1 sprocket ratio between the crank and the cam though as well, so what ever number you get on the crank pulley, just divide that by two and that is where your cam is degreed to.

 

If you set up the cam with the left side of the v notch to the farthest right side of the horizontal line, while the crank pulley is set to 0* TDC, then you move the crank in reverse by hand to square up the v notch and horizontal line on the thrust plate, then it would read somewhere close to 8* +- 1* advanced on the crank pulley. Thus your cam would be 4* advanced while the crank pulley was sitting at 0* TDC because of the 2:1 ratio.

[banzai510(hainz)]

I dont know Horw to degree a cam. One needs the spec on cam. If stock I just see if it was lined up wrong from previous owner as most case this can happen. or tooth off on oil pump dizzy install.

 

In general I set them to #2 on a performance cam with longer duration to get power sooner. for the street.

[JWJohnson]

Yeah I have only seen it done a couple time on old Ford big blocks and a couple Hemi's from drag cars, it is something after seeing a few times I still have no confidence I would do it correctly either. I do know that it isn't neccessary to pull out a degree wheel and dial it in exactly unless you are looking for the best possible performance from the specific cam. Normally factory timing marks are just perfect for 90% of the applications out there.

 

Have you ran #3 and noticed any difference? More seat-of-the-pants difference.

[banzai510(hainz)]

I have never done # 3.

these motors are so small I cant tell from a 1600 to a 1800 (both stock)myself with same carb set up.

[JWJohnson]

I didn't figure as much... Maybe some real world testing could be in the future as far as compression and MPG number? If I had access to a dyno that would help too I suppose. I have read that going from #1-#2 has shown a 10psi compression increase, I wonder if that would carry up to the next level?