Need rebuild recommendations on a 1970 460.

[sasilverbullet]

I'm going to rebuild the engine in my 70 Lincoln Mk III. It's a 460 rated at 365 hp and 500 ft lbs torque. It's rated stock at 10.5:1 and it's a totally original engine w/97k miles on it.

To keep it from pinging I've been having to run premium along with a bottle of Amsoil Octane boost (one bottle for 15 gals) and having the timing retarded to 0 degrees. I have a Pertronix II replacing the points and the carb is a fairly new Edelbrock 1604.

My goal for this rebuild is to end up with at least the stock rated hp and torque and that it run on premium with no pinging. (with the timing set correctly of course)

I'll also be towing at 4,000 lb trailer with it.

Recommendations please on how to achieve my goals.

Details like: what cam to use? pistons? valves and valve seats? Valve springs? Should I go to roller cam?

Of course I'll be replacing the cam, lifters, oil pump, all bearings, valves, valve seats, valve springs, valve guides, timing chain/gears, and having the crank turned.

I want to do this right - I'd like to drive this car a LOT for the next 10 years and not have it apart every other week for engine maintenance!

 

[Zaedock]

What's your budget? A roller cam conversion will run you about a grand alone.

 

[Ramblejam]

Since you have a '70 460, here's an option -- look at this: http://www.carcraft.com/techarticles/116_0008_87_octane_ford_460/

"...it made tire-melting torque, churning out at least 491.0 lb-ft at 3,400 rpm. It may have made even more peak torque, but the dyno brake couldn't hold the motor below 3,400. In fact, torque output was well over 400 lb-ft throughout the 3,400- to 5,500-rpm test range.

The engine didn't quite hit the magic 1hp/ci mark, but 433.1 peak hp at 5,200 rpm from a low-compression smogger is nothing to be ashamed of, especially considering the relatively mild (for a big-block) cam."

 

[skyactiv]

If you don't mind spending the money, aftermarket aluminum heads given the same CR ratio vs iron heads, allow more timing before knocking occurs.

 

[JHZR2]

Wow a 460 and a 4000 lb trailer? Those cars must have been pickup trucks with car bodies attached!

Dont have any tips, but sounds awesome.

 

[Phishin]

Originally Posted By: JHZR2
Wow a 460 and a 4000 lb trailer? Those cars must have been pickup trucks with car bodies attached!

Dont have any tips, but sounds awesome.


I agree with JHZR2.....a 4000 pound trailer towing Lincoln. Nice.

 

[loyd]

That CarCraft article is pretty good, but I would rather have dished pistons with a near-sero deck to keep the compression to no more than 8.8:1. That way you would still have some squish area left to promote combustion chamber turbulence.

 

[440Magnum]

Originally Posted By: sasilverbullet
I'm going to rebuild the engine in my 70 Lincoln Mk III. It's a 460 rated at 365 hp and 500 ft lbs torque. It's rated stock at 10.5:1 and it's a totally original engine w/97k miles on it.

To keep it from pinging I've been having to run premium along with a bottle of Amsoil Octane boost (one bottle for 15 gals) and having the timing retarded to 0 degrees. I have a Pertronix II replacing the points and the carb is a fairly new Edelbrock 1604.

My goal for this rebuild is to end up with at least the stock rated hp and torque and that it run on premium with no pinging. (with the timing set correctly of course)

I'll also be towing at 4,000 lb trailer with it.

Recommendations please on how to achieve my goals.

Details like: what cam to use? pistons? valves and valve seats? Valve springs? Should I go to roller cam?

Of course I'll be replacing the cam, lifters, oil pump, all bearings, valves, valve seats, valve springs, valve guides, timing chain/gears, and having the crank turned.

I want to do this right - I'd like to drive this car a LOT for the next 10 years and not have it apart every other week for engine maintenance!

The best recipe for reducing pinging is to convert to aluminum heads. The faster heat dissipation really pays off. Also pay attention to getting the right quench area, which is related to combustion chamber shape and piston-to-head clearance. This lets you run higher compression "closed"-chamber heads and still avoid detonation- there's almost certainly a recipe for doing this with a Ford Lima. I'm generally familiar with the technique and recipe for BB Mopars, but there's a similar method for Limas I'm sure.

Cam overlap and duration also play into it, but if you get the chamber and quench right it lets you tailor the cam more for the power curve you want with less worry about detonation. Don't get greedy with static compression even with aluminum heads- 9:1 (real) static CR is about as high as I'd go for pump gas. You don't need tons of compression for a towing engine anyway- you need mid-range power.

And by the way- if you use short-skirt hypereutectic pistons, get coated skirts. I used a set of older non-coated KB hypereutectics in the 440 build for my 66, and it sounds like a 7.2 Powerstroke when its cold from all the piston slap... and we even tore it down and RE-CHECKED the clearances to make sure they were tight enough per KB recommendations. The coating is the key to making them quiet. I've put over 20k miles on it (and thrashed it really hard at times) with no issues other than the noise, so its not a reliability worry.

 

[Clevy]

Originally Posted By: JHZR2
Wow a 460 and a 4000 lb trailer? Those cars must have been pickup trucks with car bodies attached!

Dont have any tips, but sounds awesome.


My dad had a 76 Lincoln. I remember sitting in the center on the armrest as a kid.
Dad had those mirrors that attached to the front fenders to see the trailer.
Our trailer was 24' long. Dad had put airbags in the rear to pick up the back end once it hooked up.
I was pretty young. 2 or 3 so I'm not sure exactly what it had for an engine however I do recall that trailer being attached and seeing the speed indicator at 90 mph. That car was built prior to the metric system speedo being bigger than the English.
That ole Lincoln had a back seat so big I remember my sister and I wrestling in the back, prior to all the seatbelt nonsense.
Good times.

 

[440Magnum]

Originally Posted By: JHZR2
Wow a 460 and a 4000 lb trailer? Those cars must have been pickup trucks with car bodies attached!

Dont have any tips, but sounds awesome.


Back in the 70s when my folks were somewhat into trailer camping, *most* people towed their rigs with big-block cars. Vans were considered excellent tow vehicles too, but pickups were almost only used for 5th wheel rigs. True quad-cab pickups were rare so it was hard to carry the family and trailer. For a long time only Dodge even offered one, and they did kinda own the tow market for a while with their 440-powered D/W series 3/4 and 1-ton Trailering Special.

As for cars, the general campfire wisdom was that 460-powered Fords (LTDs and Mercury station wagons mainly, Lincolns were too heavy and soft-sprung) were among the best tow machines. Cadillacs were considered poor, because even though the big 472 was a fantastic engine and the TH400 would hold together through a lot of abuse, the rear suspension was just too soft and lacked lateral stiffness and led to a lot of trailer sway. That was a complaint with most of the big coil-spring/trailing arm GM cars of the day, but less-so with Pontiacs, Buicks, Olds, and Chevies than Caddys. The big C-body Mopars (Monaco, Polara, Fury, Newport, New Yorker) were generally well-liked, but because they were unibody there were good and bad aspects. On the good side, they were lighter than similar sized Fords and GMs, so more weight could be in the payload. The 440/727 combination was every bit as tough as the 460/C6, or 455/TH400. On the downside, load-equalizing hitches for them were considerably more expensive because they had to tie in across the entire rear partial-fame in order to properly distribute the load to the unibody. If done right, they were awesome because the rear leaf suspension had great lateral stiffness. It really was pretty much a pickup truck suspension, after all.

And pretty much everyone threw the factory tow ratings out the window and designed their own tow package to their needs- it was much more of a gearhead hobby than it is today. Campgrounds were filled with the loping sounds of tow-cammed, carbureted, free-exhausted, big-block gasoline engines: Olds 455s, Chevy 454s, Ford 460s, Mopar 383 and 440's... even in the motorhomes. The GM motorhomes were front-drive 455 Olds powered (using the Toronado drivetrain). Winnebagos were all Mopwer-powered (360s up through 400 and 440s, Itascas were Chevy 350-454 powered. A diesel motorhome or tow rig was very rare, and was always someone's home-conversion using a Cummins or Cat, usually in a big GM pickup.

 

[OVERKILL]

These heads:
http://edelbrock.com/automotive_new/mc/cylheads/ford/bb_perf_rpm.shtml

Plus a roller conversion with a mild towing cam and whatever pistons Edelbrock recommends to get you to about 9:1 would work extremely well.

 

[sasilverbullet]

Originally Posted By: 440Magnum
Originally Posted By: sasilverbullet
I'm going to rebuild the engine in my 70 Lincoln Mk III. It's a 460 rated at 365 hp and 500 ft lbs torque. It's rated stock at 10.5:1 and it's a totally original engine w/97k miles on it.

To keep it from pinging I've been having to run premium along with a bottle of Amsoil Octane boost (one bottle for 15 gals) and having the timing retarded to 0 degrees. I have a Pertronix II replacing the points and the carb is a fairly new Edelbrock 1604.

My goal for this rebuild is to end up with at least the stock rated hp and torque and that it run on premium with no pinging. (with the timing set correctly of course)

I'll also be towing at 4,000 lb trailer with it.

Recommendations please on how to achieve my goals.

Details like: what cam to use? pistons? valves and valve seats? Valve springs? Should I go to roller cam?

Of course I'll be replacing the cam, lifters, oil pump, all bearings, valves, valve seats, valve springs, valve guides, timing chain/gears, and having the crank turned.

I want to do this right - I'd like to drive this car a LOT for the next 10 years and not have it apart every other week for engine maintenance!

The best recipe for reducing pinging is to convert to aluminum heads. The faster heat dissipation really pays off. Also pay attention to getting the right quench area, which is related to combustion chamber shape and piston-to-head clearance. This lets you run higher compression "closed"-chamber heads and still avoid detonation- there's almost certainly a recipe for doing this with a Ford Lima. I'm generally familiar with the technique and recipe for BB Mopars, but there's a similar method for Limas I'm sure.

Cam overlap and duration also play into it, but if you get the chamber and quench right it lets you tailor the cam more for the power curve you want with less worry about detonation. Don't get greedy with static compression even with aluminum heads- 9:1 (real) static CR is about as high as I'd go for pump gas. You don't need tons of compression for a towing engine anyway- you need mid-range power.

And by the way- if you use short-skirt hypereutectic pistons, get coated skirts. I used a set of older non-coated KB hypereutectics in the 440 build for my 66, and it sounds like a 7.2 Powerstroke when its cold from all the piston slap... and we even tore it down and RE-CHECKED the clearances to make sure they were tight enough per KB recommendations. The coating is the key to making them quiet. I've put over 20k miles on it (and thrashed it really hard at times) with no issues other than the noise, so its not a reliability worry.


Thanks for all the input - gives me much to think about! My budget won't handle the aluminum heads, I'm thinking dish pistons with a thicker head gasket should give me the lower compression I need. Will keep researching - where in Texas are you?

 

[OVERKILL]

You can often pick up a used set of aluminum Cobra Jet heads for pretty cheap. That's another option if new is out of the budget.

 

[punisher]

I honestly don't know why one would invest money in aluminum heads and roller cams for a tow engine.

1970, last year of the old high compression engines for GM and Ford. 10.5-1 is is high for that engine due to piston and combustion chamber shape. You will ping with it using regular unleaded, and figure in any carbon in the combustion chamber/piston crown, and pinging is almost an inevitability. 10.5 compression back then is not the same thing as 10.5 compression today. Newer combustion chamber shapes, piston shapes etc tame a lot of that.

Before I spent a penny on non essential performance parts, I would do a tear down. Inspect the heads, valves, VALVE SEATS, and wear items. Even a wiped out cam lobe can cause pinging sometimes.

The stock iron heads, properly rebuilt, with a newer profile cam shaft, will wake that engine up. Match your cam profile to the reduced compression of new pistons, and select cam timings that are realistic for your proposed RPM and purpose (towing). No need for roller cams as your spring pressures won't come anywhere near requiring one. I had a roller in my 468, but then again it went past 7K RPM semi regularly with steel valves and triple springs.

Build it smart and you can easily get a nice flat torque curve over 500 ft/lbs at any useable RPM range during towing. It ain't that hard. Pay extra attention to cam timing (don't get me started on Ford timing sets and the ?????? about retard/advance). As far as the heads, if they are cracked in the chamber somewhere, it alters your decision tree.

Good luck, I do love those old 460s. Gonna go hug my 460 in the RV.....maybe not.

EDIT: Read above about thick head gaskets....just don't. Usually counterproductive.

 

[SS1970chrysler]

It's been a long time since I tore into one of those, but everyone I did needed to have the block line-honed due to warpage.

 

[eljefino]

Are you near an airport? Could you get some 100LL?

Just cut 91 octane 1:10 with the stuff.

 

[sasilverbullet]

Originally Posted By: SS1970chrysler
It's been a long time since I tore into one of those, but everyone I did needed to have the block line-honed due to warpage.


Really? 70's 460 block? But I've been surprised before!

 

[sasilverbullet]

Originally Posted By: eljefino
Are you near an airport? Could you get some 100LL?

Just cut 91 octane 1:10 with the stuff.


Yep, great for around here driving, but I plan on touring the country!

 

[Merkava_4]

Originally Posted By: punisher

Good luck, I do love those old 460s. Gonna go hug my 460 in the RV.....maybe not.


LOL!!

Excellent one-liner.

 

[Trav]

I am not familiar with the engine at a rebuild level but in general my main areas of concern with older engines is the cam and making sure the valves and seats are no lead fuel compatible.

I would definitely look into a roller cam conversion, hardened seats (I don't know if they still use stellite but it was the best at one time for conversions), SS valves.
The less boring and turning of internals the better. You may not need the crank turning, you need a good machinist and someone competent with high end measuring tools.

The standard .xx over and turn the crank .xx and line bore is mickey mouse, if anyone hits you such a thing without measuring first run. A good machinist can make or break the build.
Old engines like this are great because the iron is aged and much stronger than when it was made. The tens of thousand of heating and cooling cycles have made the iron itself much stronger and more stable.

Personally I would keep the old iron heads and have them properly done for this engine, I don't like mixed alloy engines in general.
Iron block and heads or aluminum block and heads either way is fine but mixing them creates a lot of stress on gaskets.
Even an aluminum intake can cause sealing problems with iron heads more so on a V engine, aluminum expands at over twice the rate of iron and wants to tear the gasket apart.