Rebuild Engine?

[TinMan 77]

Back story. I've had this car for 39 years and bought of original owner. Parked in 1983 awoken 2016.

 

I've put 4500 miles on it since awoken. There's 119k miles on her.

 

I did rebuild the top end. I'm trying to talk myself out of rebuilding the bottom end.

 

The cross hatch was gone from the cylinder walls. There was no ridge at the top of the bore. It's burning a quart around 1500 miles or more.

 

She don't smoke (she's old enough!). Full throttle is only black residue out the pipes.

 

I've ordered a Blackstone oil analysis kit for an upcoming oil change.

 

She's at full temp (180 thermostat from an overheating issue that's been solved, I'll get a 195 back in her). This is Valvoline VR1 10w30 oil at 55mph.

 

 

This is idling at a stoplight in gear.

 

 

 

 

[danno 128]

As is often said, it depends on your goals and intentions.  If it is all original and you intend to keep it that way, then maybe keep it as it is.  But generally that is not the choice , you want something to enjoy.  Fix it right, not a band-aid. You will never lose by doing that. 

[1969_Mach1 333]

I wouldn't say your motor is worn to the point of needing a rebuild.  Oil pressure at hot idle in gear is toward the low side.  I would double check that with a mechanical gauge.  I have had Ford and GM oil pressure gauges read incorrect with particular brand sending units.  I have had good luck with Standard brand oil pressure sending units in Fords.

The oil you are using is good.  The 10W-30 viscosity is a little low for that older motor.  Valvoline doesn't have a racing 10W-40 motor oil.  Also, does that Valvoline oil have enough ZDDP for flat tappet cam motors?  I switched to the Lucus Hot Rod and Classic Car 10W-40 oil.  I like it much better than the Valvoline VR Racing oil.  Plus it has ZDDP for flat tappet cams and is also made to cling to surfaces which helps motors that sit for long periods of time.

As far as oil consumption, you might not believe this, but to the best of my knowledge Ford and GM will state 1 qt. every 1000 miles is normal.  Maybe that's to avoid replacing motors under warranty, I don't know.  Conventional oils will "burn" more than synthetic oils.  That doesn't mean the engine is using oil.  What this means is the additives to conventional oils evaporate at lower temps than synthetic oils.  Thus,  as the additives evaporate the oil level drops. 

[Rsanter 152]

If there I should no ridge I would be tempted to mic the cyl bores to really get an idea of any wear there may be.

if you want to keep the car all original I would be tempted to pull the engine for a tear down inspection. That would give me the idea if I could just put some rings and bearings in it or if I really need a full rebuild. 

If you do a full rebuild I would bore the engine as little possible and preserve as much metal as I could.

what would even be a step better would be like I did with my 69 conv.

i pulled the original numbered engine and put it in a crate. I then rebuilt a different engine, in my case I used new everything. Block, crank,rods,heads, etc

i drive the car so if I wear out or break the engine, it was not the original that got lost

 

bob

[TinMan 77]

She's a 2 barrel single exhaust automatic Mach. She's not worth keeping original from a collector standpoint. But she is a survivor. Probably not many untouched originals left.  My goal is to drive and drive a lot.  Right now I'd love to make the 55th anniversary at Charlotte in 2019.

I'll do a compression check and the oil analysis. If this comes back fine. I'm just gonna keep driving her! :) :) :)

The body will stay a survivor. Not so sure about the drive train. I'd like for the FMX and manual drums to go away.

[69RavenConv 286]

2 hours ago, TinMan said:

I'll do a compression check and the oil analysis. If this comes back fine. I'm just gonna keep driving her! :) :) :)

Good choice. If she's running, keep her running and enjoy. Pay close attention for any new developments that may require more attention and you'll be ok.

My situation is similar - an unremarkable F-code convertible that I've owned since I was in high school. Mine is not a survivor, it deteriorated too far and required a full restoration - but it retains the original drive train, suspension, drum brakes, and , well, everything it had back in 1974 when I bought it except for a 1974 AM/FM radio, dual exhaust, Edelbrock F4B manifold, Ansen Sprints, and Holley carb (I still have the original parts on the shelf, just in case:).

I often think I should have built a stroker, added a T5 and disk brakes, etc, but then I stop and think they aren't making any more '69 Mustangs and I get a certain thrill driving a period correct car that's not around any more. A little scary sometimes, but still fun.

[TinMan 77]

11 hours ago, 69RavenConv said:

I often think I should have built a stroker, added a T5 and disk brakes, etc, but then I stop and think they aren't making any more '69 Mustangs and I get a certain thrill driving a period correct car that's not around any more. A little scary sometimes, but still fun.

I'm torn. Your post didn't help any either!  I would love a T5 and discs. And yes. The manual drums and vague steering are scary!

[1969_Mach1 333]

TinMan, it is extremely rare these days to find a 1969 Mach 1, or any model car of that era, in the condition yours is in.  I wouldn't do too much with "aftermarket" upgrades.  It will reduce the value of your car.  Smaller stuff like exhaust, intake manifold, carb are okay.  But save any original parts you remove.  If you want disk brakes, you can install original front disk brakes.  I think the only parts not being reproduced or available from a local parts store are the spindles and splash guards.  The vague steering can be helped by rebuilding the steering linkage an very important, rebuild the control valve and be certain it's adjusted correctly.  Rebuilding, or simply adjusting the steering box correctly will help as well.  You won't completely eliminate the vague steering, but definitely make it better.  At 119K miles, a complete front suspension and steering rebuild is probably in order.

[69RavenConv 286]

On 8/23/2017 at 10:46 AM, TinMan said:

I'm torn. Your post didn't help any either!  I would love a T5 and discs. And yes. The manual drums and vague steering are scary!

LOL! I know, I know! Maybe someday I'll wise up and do the upgrades and quit taking chances in modern traffic. But for now, there's something about that "time machine" feeling ... as long as I maintain lots of stopping distance. :)