My '63 F250 Unibody with a freshly <200mi rebuilt 292 motor seems to be running great... and sounds great!

Anyway, it's got the 4-speed granny tranny. For engine break-in, the original owners manual says, "It's not necessary for you to drive your truck at consistently low road speeds during the break-in period. Vary the speed occasionally up to 40 mph."

I love my truck and I knew I wasn't buying a highway cruiser, but I have to admit that 40 mph is a little bit lower than what I expected for a top end. I was figuring 50, but don't care, just want to take good care of her. What is your recommendation for the top end for break-in as well as post break-in??

Thanks,
Eric

 

Here's my unscientific break-in info:

-vary the speed of the motor. Up and down 5 to 10 mph will do.

-stay under 60 or 70% of redline.

-give it a full-throttle run up once in a while. This puts a lot of pressure on the rings and makes them seat better.


With that granny tranny, you can put some tall gears in the diff for better cruising. At $500 or so for a newly rebuilt 9", it's much cheaper than an OD and easier too. Or maybe you get one for $75 from the scrappy and turn up the radio to cover the whine.....

 

Well Ive also got a rebuilt enigne and the best thing is too constantly vary the RPMs and change the oil often. Also to break in the rings, take her on the road and in high gear, go full throttle from 35-55mph at least 10 times, this seats the rings. You need to seat the rings as soon as possible, if you dont break em in, the enigne will never run right, and after a few hundered miles you lose the chance to seat the rings properly. Btw I you can have some fun with it even when its new, ive already been over 100mph in my 66 with the rebuilt engine.

 

First off... it would be cool if my completely stock '63 had a tachometer. So, I really understand engines and redlines well enough that I wouldn't need to ask.

Secondly, there is NO way that a 292 with the original granny gear tranny can go 100. Not!

Eric

 

Hey man, The people in FTE are hear for support, advice, FUN, and whatever else you have in mind about a Ford truck. Your reply to the ones who wanted to help was a little harsh.

 

I am not 'A Typical Engineer', I am an 'Atypical Engineer'. I am a cynic and always question everything. No harshness intended.

Eric

 

No but a 352FE easily does. There is a HUGE difference between the 292 y-block and a 352FE, esciapally mine as it is modified. Im not reccomending he go 100 or even attempt it, just letting him know to have a little fun with it.

 

Eric, If the rear gearing is in the 3.00-3.25 range, there is no reason why it shouldn't. The original tranny is turning 1 to 1. A 3.75 or 4.11 rear ratio could make that harder to get.

My 66 FE, C6, 3.00 rear P235 70 15 tires, when checked the other day is running 85 mph at 3000 rpms, so it will reach 100 mph way before the engine goes into orbit.

You can pick up a tach for about $40.00 and they are only 3 wires to connect.

just my 2

John

 

You don't say what your rear gear ratio is,

Nor what tire diameters you run,

Nor if you have correct speedo drive & driven gear combos in & for your set up.

I've some knowledge on the subject. I'm here to tell you a 292 "Y" block certainly will do 100, or more MPH, with correct set up presenting mechanical criteria to achieve it.

True enough you won't see 100 in granny gear. But riding in high gear your granny's along for a ride & has no bearing at all on final work product a vehicle produces.

FoMoCo trannies, not specifically O/D or AOD, have, as my friend John points out 1:1 final output ratio. Also, as John also points, your speed is relative to final rear gear ratio [ plus as I mentioned tire diameter] X RPM. Every any "Y" Block I ever saw was capable of 4K RPM at least, if it half way ran at all.

My 460 is churning 2650 2675 @ 70 on 31.5s & 3.00:1 rear gear. At 4200 I'm well over 125 and in 12.60 seconds ET, at that. Your 292 may be sluggish in comparison to those stats, but it certainly should see the century mark, eventually, if you have the right gears and the time to run it up there.

The only thing "Y" Blocks ever showed me was they liked to wind and wind and wind. In fact they almost run like flat heads, winding forever & getting there eventually. I'm not dissing 292s I'm just disagreeing with your statement "Secondly,there's NO way that a 292 with a greanny gear tranny can go 100. Not!"
I say you're wrong, unless you have a short rear gear because the tranny has no bearing on top end in high gear, unless it is Over Driven. . . . PERIOD!

FBp

 

Yep your right Fordboypete. I think I heard one time that the biggest factor in how fast you can go is aerodynamics and RPMs. At 100mph the wind resitance on these flat faced trucks is a lot, but if youve got the power and your in your powerband, you can just keep going til your engine gos above your powerband, my engine has a redline of about 4500, I dont know what RPM's I was turning at 100mph, but it was a lot, It was still pulling hard btw before I let off. Maybe I could hit 110 or 115 I dont know, what I do is, 100mph with manual steering and Bias ply tires will defintly get your aderenline running, it was everything I could do too keep it on the road, very scary.

 

I have had several engine builders tell me that it is not just the accelerating that helps them to break in but the deceleration using the enging as a break. You can break an engine in and never come out of first gear.

 

It also depends on how coarse of stone was used on the bore and what type of rings used. With a bore that was fine honed, polished with 600 grit by hand then burnished with maple blocks like they use on Radial engine barrels, add moly coated rings it takes around 15,000 miles to seat but you will have a tight bore motor that will run over 500,000 miles. This mileage is running them hard not a garage queen. Go cheap with a coarse bore, cast iron rings and seat within 600 miles that last under 80,000 miles. Been there done that on both over the years. My opinions from my results.

Carl....=o&o>....

 

it's a good idea not to drive faster than the speed rating on your tires...

 

Whoops, I didnt know they had a speed rating?

 

Do they have recaps rated to 200 mph, drum brakes for 150? whats that red zone on a tach for, decoration? White tire smoke with red and blue party lights don't mix.

Carl....=o&o>....