Initial timing question???

N

Nevadasmith

Active member
So new engine build for my 170 Boss bronco, hahaha,
D2 250 block, knife edged ballanced crank
Ballanced rods, and pistons
2.3l hsc flat tops .030 over
Head milled .045"
E0 hex log, 60 hours in port and Polish, mostly in the log and the exhaust ports, pollished combustion Chambers
Should be 9.27-1 comp
Erson rv10h 280/280 cam
Dsii dizzy stock to E0 specks
Ford "e style" 68,000v coil, AAP 45 iridium spark plugs, 1969, pre smog timing set on the cam
Motocraft 2150 1.08 on vi adapter, not direct mount. 195* thermostat 4000' elevation.
Actual deck hight is .137-.139"

I set initial timing at 10* and it runs ok, it's flooding every time I shut it off...... I am switching to a yfa carb tomorrow, have to redo all the linkages again, but it just doesn't feel right, no hessitation on hot restart. But it diesles when I shut off, and at places in the rpm curve it has mind blowing torque, bit it comes in and out of it???? Should I be setting intial timing at 8*? 12*? 15*? , Any mods I should make to the yfa before I put it on??? It's a nos calibration is 76 Maverick 4.1L 49 States. Open to suggestions, I feel like if this thing ran consistent, I could smoke 35" tires and get 18-20 mpg....... Thanks in advance!!!![image]https://photos.app.goo.gl/7ZN97Jgdfbx4WBgu9[/image]
 
Oh yeah forgot I upgraded to SBC dual damper valve springs, with hardened spring seats!!!!
14 miles on the truck after 30 min 2k+ cam break in!!!
 
welcome back nother bronk.

Plez B4 U change out stuff get this 1 runnin right (C my quote in sig).

Could it B the dizzy?
Like 2 no more bout it (& might not B the issue anyway).
 
Also a buddy is building my old engine with 255 v8 pistons comp cams 260/260 cam stock d5 250 head, stock 250 block, crank yfa carb same altitude, dsii dizzy what is a good initial timing for that build? Deck hight should be .030, compression should be 9.3-1, thanks!
 
chad":2ypy9zmg said:
welcome back nother bronk.

Plez B4 U change out stuff get this 1 runnin right (C my quote in sig).

Could it B the dizzy?
Like 2 no more bout it (& might not B the issue anyway).
Click to expand...
I am 95% sure the power valve is leaking again on this 2150, it has been and on going problem, 3 power valves, 6 gaskets, no backfire, runs good for 2-3weeks then I have to change power valve and gasket again!!!!!!!! Then it runs good ish again for 2-3 weeks...... at least on the old 250 on the new 250 it made it through cam break-in!!!!! ......but seriously failed the test drive!!! But I'm going to do the yfa swap and a full new exhaust, before I do anything else!!! So only 2 things this time!!!!! But I still feel like this engine is wanting some thing I'm not giving It!!!
 
There is more than initial advance for proper performance.
Stock settings are not the best.
You can destroy an engine by just increasing the initial advance.
Check out my DS11's in the small six for sale section.
I recurve them to your engine combo. Bill
 
never heard that w/a carb esp the 2100 (the bestist) - could it B something w/the fuel pressure?

I got a YF that has served me 30+ yrs, so like it, YFA has some extras on it tho...
 
So quick update, new 2-1/4 exhaust, and a yfa carb, ended up at 15* initial timing, and it is running much better!!!!!

Thanks for the help!
 
Good to hear! That is an impressive build it should go pretty good.
 
Nevadasmith":1qetpbo9 said:
So quick update, new 2-1/4 exhaust, and a yfa carb, ended up at 15* initial timing, and it is running much better!!!!!

Thanks for the help!
Click to expand...
But what is your total advance?? & at what RPM??
 
bmbm40":2squsce9 said:
Good to hear! That is an impressive build it should go pretty good.
Click to expand...
Yeah it pulls 35" tires pretty good now! I haven't gone through a tank of fuel yet to check mpg but I suspect 16-18 mixed city and highway!
 
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