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Discussion Starter #1
My Dad and I bought a 1968 F100 Ranger to restore.
The original motor was a 360.
But we bought a 390 crankshaft and rods to put in it.
We also bored it .030 over with Sealed Pro 9.5:1 pistons.
Added a 1968 390GT camshaft, and an Edelbrock Performer RPM aluminum intake.
And then added a Holley 650 double-pumper.
I need all of the advice I can get on how to fine tune this engine, seeing that this is our first one and we know absolutely nothing about FE engines.
I have found a friend in Illinois named Bob Hasty who is guiding me pretty well.
Right now there is a small hesitation with the engine when I reach about 5000 rpm.
I have no idea why?
Can someone help?
Thanks!
 

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Tune it EXACTLY like you tun ANY gasoline powered engine.

Set Initial Timing

Set MAX Timing

Make sure your timing is All In where you need it to be in your power band

Warm engine and adjust AF mixture screws

Ensure that you properly explain what you mean by it hesitates at about 5000 rpms?

I.E. WHAT is the position of the throttle when this hesitation occurs? FULL throttle? Gradual throttle? 1/4 throttle? Is it a Primary to Secondary Transition hesitation?

We really need more information....
 

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Could be your valve train has reached it's max.
 

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Could be your valve train has reached it's max.
I agree, did you change valve springs? If not anything over 4500 rpm, expect an old FE to start floating soon

Not that it's related, but are you running headers? If not, it wont make any power past 4500 or so anyway, even if not floating the valves.

Consider having the distributor recurved for 12 initial, 38 total, all in by 2800 or so, it'll wake it up part throttle

Set idle a/f for best idle, and you are pretty close.
 

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Not really sure what you mean by "hesitates" at 5000. Does it go ahead and pull past or kinda runs outta steam? 5k is getting close to redline for a basically stock FE.... M2C
 
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