Stock timing advance on HF 6.5HP clone?

[Matt1995]

If anyone knows the exact ignition timing advance on one of these engines, let me know, i'd really appreciate it. I was thinking it was in the 8 degree range, but not sure. I'm going to try running one of these engine on a DIY standalone engine computer and eventually fuel inject it. Just need to know where to set timing to start off with. Thanks!

 

[freakboy]

why would you fuel inject it.

 

[Matt1995]

why would you fuel inject it.

Because I can ...and automotive engine controls are my hobby-I run both my turbocharged cars with DIY engine computers). Actually, there is quite a bit of power to be made by running variable ignition timing advance(like a car engine), and also being able to control the air/fuel ratio precisely. Not to mention it would make adding a small turbocharger to it much easier..I've already got the crankshaft trigger sensor working and making spark with an automotive ignition coil, just need to make a mount bracket and drive adapter to fit the sensor to the engine.

Which brings me to my question- I really need to know the stock timing advance in degrees BTDC, for those that know what i'm talking about. It will help initial software setup on the engine control computer, and also give me somewhere to start my base timing values. I've already used a timing light and marked the flywheel where it's sparking as it is, so at least I know where timing should end up when i get it running off of the computer. I've searched the net, and haven't found anything of value.

 

[anderkart]

I've searched the net, and haven't found anything of value.

Try a search for "clone timing" at this forum: http://karting.4cycle.com/forumdisplay.php?f=71
(you may have to sign up before you can search here)

I just quickly sifted through a few threads of this search and seemed to find conflicting (stock) timing specs being reported for various 6.5 clones. I've read that theres been many diferent vendors supplying components for these motors over the years and sometimes they're specs have been known to drift a good bit...

 

[Matt1995]

Try a search for "clone timing" at this forum: http://karting.4cycle.com/forumdisplay.php?f=71
(you may have to sign up before you can search here)

I just quickly sifted through a few threads of this search and seemed to find conflicting (stock) timing specs being reported for various 6.5 clones. I've read that theres been many diferent vendors supplying components for these motors over the years and sometimes they're specs have been known to drift a good bit...

Thank you! I'll give that a shot.

 

[Rickracer]

For what you're doing, I wouldn't use posted specs anyway. I'd either make a TDC pointer, or use a certain immoveable reference point on the block and mark the flywheel there when the piston is at TDC, then use a dial timing light to see where it's firing.

 

[Matt1995]

Yep, i've basically already done this. Only thing is the exact TDC mark I made..I did the old screwdriver in the plug hole trick, and it's not perfect. I really need to take off the side cover and use the crank/cam alignment marks to reference TDC. Either way, with the marks I have, I know where it's firing stock, so at least I can match it. My actual timing values for the computer may not be accurate, but that's fine. At least I can match.

 

[Matt1995]

Hahaha..it runs! Got the computer running ignition only for now.. I took a short video of it running..Fun stuff

http://www.youtube.com/watch?v=a2mHLttBkq4

 

[1992suburban]

BAD @SS!!

I am impressed. show us the setup and how you did this!!

 

[Matt1995]

BAD @SS!!

I am impressed. show us the setup and how you did this!!

Computer control is with a MegaSquirt DIY engine computer. I used a Ford 36 tooth crankshaft timing wheel and Hall effect sensor to read the teeth, and that information is sent to the Megasquirt computer for rpm and crankshaft position. I can adjust and set ignition advance to anywhere I want to, and dependent on rpm(increase advance as rpm gets higher, run higher octane fuel and increase beyond stock, ect).

Once money permits, i'll fab up a single fuel injector setup and ditch the carb. It would be really cool to get it dynoed before and after to see what kind of power gains can be had by using variable ignition timing and air/fuel ratio tunning.

Oh BTW, I saw that link for the factory service manual(thanks!), and stock timing is fixed at 20 degrees BTDC.

Here is a pic of the trigger wheel and sensor:

http://img199.imageshack.us/img199/5913/wheelandsensormounted.jpg

I used a different sensor than in that pic, but you get the idea. It was pretty simple to fab up actually. I also use a single ignition coil from a Jeep 4.0L engine. No good way to use the stock coil, as its all one contained unit.

 

[DCC!]

what excatly does it take to fuel inject an engine?