I have a unusual situation where a Mummert-built stroker shortblock with massaged "G" heads/ARP bolts/Best headgaskets/sits in my basement covered in plastic. I started the project originally (two years ago) because diminishing oil pressure and leaky orig. steel headgaskets warned that the handwriting was likely on the wall re: the 100K mi.+ original 55 292.

But, the addition of "Stop-Leak, propylene coolant, and a lot of Lucas oil viscosity expander have brought the orig. motor back to life. Since I installed tubular pushrods, Pony-built teapot, high ratio rockers, and re-calibrated the Loadomatic with a mechanical advance limiter (using a SUN machine), the headgaskets have quit leaking, and the original motor runs like frigging gangbusters (with no coolant pressure/modified cap to prevent leaking). I know eventually the coolant system will sludge-up, but I have no worries since there is a new block & alum. radiator waiting in the wings. Every time I get to thinking it might be time to swap in the new motor, I take the car for a spin and run the piss out of the orig. mill. IT RUNS LIKE A FRIGGING SCALDED CAT! How can I justify pulling an engine that runs this good? If it wasn't for the imbalance vibrations, I wouldn't even consider it (any rpm below 4000 causes the steering wheel to shake big-time). Still, the new motor will require premium fuel (9.5:1 CR), and a lot of installation & break-in grief (the heart attack I had a couple years back sort of took the wind out of my "engine swap" sails, so to speak).

So, should I run the original motor until it breaks?" Being an original factory assembled Ford Y-Block, it might run for another 10 years at this rate. THE HARDER I PUSH IT, THE MORE IT WANTS TO RUN! The car will do (speedo calibrated) 125mph easy (orig. drum brakes keep those tests to a minimum though).



So, if I keep the built shortblock properly encased in plastic, what's the harm?

6 VOLTS/POS. GRD. NW INDIANA

Im in the same boat as you.. My motor has low oil pressure, leaks etc, yet the ol' gal starts first time everytime and pulls like a freight train.. Guess it comes down to "if it aint broke dont fix"



"Came too close to dying to stop living now!"

I have to reflect re: Karol Miller's comments' about his '56 312 Bonneville car with over 100K on it. "Nice & loose" (?) No way to duplicate that. Is the ring wear & resultant loss of compression more important than the reduced friction? I remember old time FoMoCo mechanics talking about having to tow-drag new rebuilt motors to break them in enough so they could be started normally. Even with modern machining tolerances, could a new motor (all things being equal) possibly approach the HP potential of an old worn engine in good condition?

6 VOLTS/POS. GRD. NW INDIANA

I think it has to do with the fact that the more miles an engine has on it the looser it gets. Clearances open up and it runs better aslong as compression is good.  The original engine in my Bird was smokeing a little and using some oil but ran great until the rod went through the side of the block. Racing engines are set at looser clearances for a reason.

Here's hoping I will still remember how everything goes together when the orig. mill finally gives up. At this rate, I may be in a nursing home by then.

6 VOLTS/POS. GRD. NW INDIANA

I've heard something like that in the past. Knowing what I know now, I don't buy it. I'd have to hear it from someone who was there, saw it with their own two eyes and can prove it. If the engine is that tight, something is wrong.





All things being equal, yes it will approach the potential. But realistically, if you rebuild, why do it equal? We've learned a lot in 55 years. This is not necessarily expensive stuff. Apply some of that knowledge and it will absolutely be a stronger engine. I'd be throwing that stroker in there and keeping this engine as a backup, just in case.


Lawrenceville, GA

 I'd be throwing that stroker in there and keeping this engine as a backup, just in case.[/quote]

But that's just me!!

Frank/Rebop

Bristol, In ( by Elkhart) 

[quote][b]charliemccraney (9/27/2012)

If the engine is that tight, something is wrong.



Indeed. I'm curious also whether an engine like that would likely last the rebuilder's warranty period if it WAS loosened up by towing. You or I would take it apart and redo it, but some people might not if they thought they could get away with it.

6 VOLTS/POS. GRD. NW INDIANA

Smoky always said: "The Damn Things Run The Hardest Just Before They Blow!"

I hear where you’re coming from, Dan. If the engine you’ve got is running great guns (after all of your keep-it-going efforts), it seems crazy, in one sense, to go through the grief of an engine swap and getting the new combination sorted out so that it is truly running ‘right’.



As I get older, I’m finding that I seem to have enough to do without looking for projects (potential grief/trouble) to engage in that don’t need to be done.



REFLECTION: We’re all only going this way once, so you’ve got to ask yourself how happy you’re going to be at the end of the game if you don’t get to see how that engine you struggled to get built ran…



BET: IF you didn’t have a back-up engine ready to be installed, the original engine would have died a long time ago. [Murphy’s Law, Rule # 13]



CONSIDERATION: Wouldn’t you rather change engines when it’s convenient for you (your time schedule) rather than when the other engine fails and you HAVE TO change engines in order to be able to drive your car?



THOUGHT: Changing engines during the coming winter months could make the winter go faster...



ALSO: I've heard more than one person say what Richard reported... engines run best just before they let go!



I wish you lived closer, I’d enjoy helping you make the swap! Best Wishes.


NoShortcuts
a.k.a. Charlie Brown
near Syracuse, New York