Good engine for my '61 Bonneville?

[Bonne61]

Hey there,

To keep a long story short, I am interested if anyone (preferably in Australia, hopefully Queensland) would have a 389 in very good running condition, or alternatively another engine that would bolt straight into my car (& onto the existing Hydramatic transmission). 

I don't need a performance motor as this car is a cruiser for us however we intend to do plenty of miles in it, so it needs to be solid & reliable.

Big ask I know, but it appears as if mine has spun a bearing & I'm just casting about for options before I get mine rebuilt.

Thanxx

[JUSTA6]

7 hours ago, Bonne61 said:

Hey there,

To keep a long story short, I am interested if anyone (preferably in Australia, hopefully Queensland) would have a 389 in very good running condition, or alternatively another engine that would bolt straight into my car (& onto the existing Hydramatic transmission). 

I don't need a performance motor as this car is a cruiser for us however we intend to do plenty of miles in it, so it needs to be solid & reliable.

Big ask I know, but it appears as if mine has spun a bearing & I'm just casting about for options before I get mine rebuilt.

Thanxx

Usually...Not ALWAYS,  you will spin a rod bearing.  Pretty tough to spin a crank bearing.  So they will machine the rod journals down 10 20 30 over stock spec's.  Whatever it takes to remove the scratches/damage and rebuild with the matching bearings.  Same time they will check cyl bore, for a ridge at the top of the cyl (normal wear N use)  Shop will also clean all oil passages.  Most of all you will have a warranty.  Used engine is a crapshoot at best,  Have to ask yourself how long has it even been sitting around?  If you can pick it up dirt cheap and it matches what your taking out.  Then have that one rebuilt, pull N replace.  BUT remember...Original engine block to the car is far more valuable for overall worth of the car.  Do NOT discard if you use another engine. Good luck on whatever you decide.

[64 kiwi boni]

i am with JustA on this one Paul, rebuild your motor over finding a 389 anywhere that isnt in need of a rebuild anyway.

then you know exactly what you have for years to come!

Hopefully Fitzy will see your post and he can tell you whats invloved as he justA rebuilt his one in the 65.

i think the main thing is to find a good machine shop thats going to do the work properly and not rip you off 

[Fitzy]

Hi Paul - the guys are right. Keep your vehicle matching numbers by retaining that engine. Pontiacs are sturdy motors and a rebuild is worth undertaking. I did mine myself, but the machining was $4k. The parts were about $2k but I replaced EVERYTHING. If you employ an engine builder to do the job, I reckon you're looking at $8 - 10k. That sounds expensive, but it'll outlive you once completed. Oh, and put in a waterwheel type water pump and a decent radiator. Your new engine will thank you for it.

[64 kiwi boni]

7 hours ago, Fitzy said:

Hi Paul - the guys are right. Keep your vehicle matching numbers by retaining that engine. Pontiacs are sturdy motors and a rebuild is worth undertaking. I did mine myself, but the machining was $4k. The parts were about $2k but I replaced EVERYTHING. If you employ an engine builder to do the job, I reckon you're looking at $8 - 10k. That sounds expensive, but it'll outlive you once completed. Oh, and put in a waterwheel type water pump and a decent radiator. Your new engine will thank you for it.

da Man!

[Fitzy]

Now...having said all that, if I could wind the clock back I would have removed the 389 & TH400 (in my car) stored them and dropped in a modern injected LS motor and overdrive auto. This will upset the Pontiac purists but nothing can compare to modern refinements for enhanced power, reliability & fuel economy. The gig with Chev motors is unsurpassed cheap parts and plentiful go fast bits.

Or, you could source a 455 (all Pontiacs use the same physical block size, bar a very few exceptions) and use that. They're a torque monster.