Vintage Mustang Forums banner
  • Hey everyone! Enter your ride HERE to be a part of this month's Ride of the Month Challenge!

1 - 7 of 7 Posts

·
Registered
Joined
·
129 Posts
Discussion Starter · #1 ·
I have a modified 289 engine rebuild D code 64.5 Mustang, bored 4.04, comp 9.4-1, camshaft 106 deg, balanced, solid lifters, aluminum roller rockers, pertronix electronic ignition (in distributor only), stock coil, QuickFuel 600 carb, and some other minor engine tweaks mated to a 5 speed manual.
Having cold start and stuttering/balking on acceleration issues. Sometimes kills on cold start from dead stop.
What should the timing be set at?
Any thoughts if incorrect timing or ?? on this set up could be a cause?
Thanks
beefer
 

·
Registered
Joined
·
1,249 Posts
106 degree love separation is pretty narrow. I could be wrong but I think that would contribute to poorer idle quality. You didn't include the rest of the cam profile. But I would say it's probably a decent size cam. That and choke as @awhtx has suggested could contribute to cold idle issues.
 

·
Premium Member
Joined
·
7,449 Posts
First, where you picking your Dist. advance vac? Second, what is your initial timing now?
It's pretty darn impossible to answer the timing question as every engine is different.
Example: I run 18º initial in my D code 333 stroker with "curved" Distributor likes running full time Dist. vac. My cam is a full roller with a LSA of 113.3 and 10.6 CR. It's steerable but very strong too.
 

·
Registered
Joined
·
129 Posts
Discussion Starter · #5 ·
106 degree love separation is pretty narrow. I could be wrong but I think that would contribute to poorer idle quality. You didn't include the rest of the cam profile. But I would say it's probably a decent size cam. That and choke as @awhtx has suggested could contribute to cold idle issues.
It has an electric choke. I haven't been happy with they carb for quite awhile.
Attached are the engine build details with more detail.
Hope you can read this.
Please let me know what you think. Right now the timing is around 10 deg BTDC
thanks
 

Attachments

·
Premium Member
Joined
·
7,449 Posts
It has an electric choke. I haven't been happy with they carb for quite awhile.
Attached are the engine build details with more detail.
Hope you can read this.
Please let me know what you think. Right now the timing is around 10 deg BTDC
thanks
Without looking at your details "yet" the 10º initial is low. If your 9.4 (static) is accurate, your dynamic CR is is probably a point lower, depending on the cam's over events. This being the case, I see it going to 14º, easily.
...evene a little higher. Just takes some testing and tuning time, all the while keeping records of your changes.
 

·
Registered
Joined
·
3,081 Posts
i prefer setting my initial timing at between 10-14 initial for most engines. that seems to work best for most engines, and tune from there.

remember that the vacuum advance needs to be disconnected and plugged when setting the initial timing.

something else to look for is vacuum leaks, they will cause low speed drivability issues.
 
1 - 7 of 7 Posts
Top