timing

[codycatract]

hey got a little question for ya guys. i have a 79 620 just got it in, i put a late 73 distributer in it and got it timed best i could. one problem it pulls hills just as bad as my 22r in my yota with 36s and stock gears. its an l16 and it has 215 bfgs is it timed wrong or are they that gut less all help appreciated thanks

[banzai510(hainz)]

a 1979 620???????should have a L20 motor and a matchbox EI distributor.

 

So you put a point distributor in there?

and theres a L16 motor in there also.

 

Sounds like your going backwards

 

I will assume the later 620s had a higher diff ratio so there will be some acceleration loss there as most L16 in thrucks had a lower 4.375 when they had l16s in them

Also 215 what tires???????? 215/75 series. yeah that can slow it down also with that gear ration and a L16.

 

Now for the ignition.

a 79 Matchbox just uses 2 wires that go to the coil. +side and minus side. However a 79 will have a EI low resisitance coil which is made to run on the 12-14volts. Now if you put a POINT dizzy on there you need to get a point coil of about 1.2-1.6 ohms and a ballast resisitor of close to equel value otherwise your POINTS will burn up.Cause the condensor cant handle the extra current. So your points will arch.

Then you need to make a HOT START wire to bypass the ballast resisitor to make this correct. Im sure a 79 dont have this.

 

I will assume you put the L16 points dizzy on as a set . As a L16 dizzy does not line up and fit the L20 mount/pedastal tang hold down plate.

 

So help clear us up on this distributor issue.

 

Datzenmike or somebody else can finnish this up for you.

read Jason grays write up

olddatsuns.com in tech section

 

I think best to get same dizzy that was for a 79, A 79 Matchbox

 

What does your timming light say?????? I know you have a nice new timming light and what ti tell us what you got ?right?

[datzenmike]

Ha ha ha. I doubt timing is the problem.

 

The '79 has a 4.11 rear end in it. Add 215 tires and an L16?? and you have a prescription for no top end power. Any other 620 rear end except the '74 automatic will be a 4.375 and should add a bit more go to it.

 

Stock 620 tires are 6.00 X 14 or 150/70R14 -ish equivalent. You say 215 tires but this is meaningless without the rest of the dimensions.

[codycatract]

the tires are 215/75R15. ya i blew up the original motor, l20b, found a 73 l6b for 100 with 140k on it so i put it in and just found the distributer that was same year as motor. my points are fine and i put well over a 1000 miles on it the havent even really changed color and are not pitted. my timing light shows the 5 degree mark like an inch where it should be, but if i put it where it should be on time it spark knocks bad. and i had one of my buddies that knows datsuns better then me and he said my top end is on time with bottom end

[Braden]

WHERE IS YOUR OLD DISTRIBUTOR??????????????????????????????????????????????!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

[datzenmike]

215/75R15s are 4.88" taller than the stock tires. At 50 MPH on speedo you are doing about 60 actual.

[codycatract]

WHERE IS YOUR OLD DISTRIBUTOR??????????????????????????????????????????????!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

long story short, blew it up wnated 2 wheel drive toyota, sold datsun to buddy then ended up wanting it back. these thing you have to have dialed to run good and nothin the same. toyotas are alot more simple, hahh well thanks for the help ill get these down sooner or later

[hang_510]

timing is everything

 

toyotas are alot more simple

between a 22r and an L16 :blink: whUt???

only a briggs & stratton is simpler

 

do you mean elecronic ignition VS points, well then ya.

[codycatract]

timing is everything

 

 

between a 22r and an L16 :blink: whUt???

only a briggs & stratton is simpler

 

do you mean elecronic ignition VS points, well then ya.

well im rebuilding an l20b so ill just get 79 distributer and play it from there, thanks for the help guys

[Jayden71]

WOW!! I got 195/75/14's with a L16. I thought that was bad, I can hold 50mph up 7% Ladd Canyon grade tho. I cant imagine 215/15's. I bet you could walk up a hill faster than your truck goes!! :blink: