I have a 1972 Lincoln 460 rebuilt to og. specs bored 30 and polished crankshaft.
What happened in the 1972 460cid to decrease so much hp and tq. I understand in the 1972 the hp is 212 and tq around mid 300 vs. the 1969 - 1971 the hp was 365 and the tq was 500.

They both have the same bore 4.36 and stroke 3.85, 4 barrel carb. The 1972 has a compression of 8:5:1 and the 69-71 has 10:5:1

My question is how can i make the same hp and tq as the 69-71 engines and possibly a little more. Ideally i would like to make 390- 420hp and keep my tq up near 500 with no blowers or nitro added on and keep the c6 trans.

Any strong suggestions would be great!
THANX

 

You can thank smog regs & the detuning of the venerable large version of the beloved 385 block. I had a 1970 Town Car with the 460-4V. Compression ratio was in the 11:1 range with spark timing to match and a 92 octane fuel requirement. What a go-mobile for around 5000 pounds and still with a 2:73 rear axle! Gas mileage 14-17 MPG.

Sometimes regret selling it.

For more power? You will probably need to increase compression, port & polish intake runners, change camshafts, go to a roller valvetrain - all the usual stuff. Top it off with a high energy spark system and a new high quality carburetor. Depending on where you want the power, stroking the engine might also be of benefit.

dn.

 

Most of the compression in the 771 and older 460 was due to the heads if you can find a set of 71 or older heads you will increase your compression I would recommend any of the DOVE heads if you can find them

 

someone can correct me if i am wrong, but around 1972 mfg's began rating engines using the SAE net method. they starting testing the engines at the rear end, not the flywheel, using all the original factory equipment. this, along with the previously mentioned decrease in compression and increase in smog equipment is why the numbers decreased so dramatically. the engine compartment tag for the 460 i have in a 70 lincoln has numbers like 360 hp @ 4600 rpms.

there are plenty of aftermarket pistons which will raise compression using your existing heads, but your heads need exhaust port work...and if your going to pay someone to do that, have them put in bigger valves while your spending your hard earned cash. a good aftermarket intake will also help to remove some un-needed weight and improve intake air flow...cheers, garsten tucson,az

 

The three primary differences are 1) as mentioned above, the change to "net hp ratings; 2) a timing set that direly retards the cam timing ; 3) the D2VE cylinder heads, considered by far the worst of the cyl. head choices.

The older C8VE, C9VE, and D0VE heads are very similar to each other and will as stated raise the compression nicely (though they won't change the deck height, which is excessive on a stock engine); the 1973 D3VE heads are similar to the C8VE, C9VE, & D0VE heads with a considerably larger combustion chamber and a reduced short-side radius on the ports. Any of these would be better choices than the D2VE heads if that is what you have. Note, however, the D3VE heads won't raise the compression, unless you also change pistons, probably not your first choice with a recent rebuild.

 

Are the older heads as you stated a direct bolt on or will i need to make any changes with valves or any porting?

 

are the older heads as you stated a direct bolt on or will i need to make any changes with valves or any porting,

 

no they will bolt on and you shouldn't need to change anything unless you happen to get ahold of CJ heads. As stated they will increase your compression but not as much as the earlier engines because in 71 they also increased the deck hieght of th eblock

 

They are, more or less, a direct bolt-on. You will want to check your pushrod length to verify valvetrain geometry.

If you are going to install earlier heads, it is worth the trouble to blend the bowls of the ports and remove the Thermactor boss, or shape it. This can be worth 20-30 hp if done correctly and is relatively easy to do. The exhaust ports are not particularly good as cast but have potential. The stock exhaust manifolds are pretty dismal as well; use headers if possible..

The earlier style timing set, an aftermarket or recurved factory distributor, and a decent cam will all help quite a bit, too. If you have some more $$$, add an Edelbrock Performer and a Holley 750 vacuum secondary carburetor, if they will fit under your hood. The stock intake is not really too bad at low revs, but is all done by 4000 rpm.

Hope it helps- Mike

 

Everybody seems to have forgotten that there was one more BIG reason that the ratings fell on the newer blocks and that was that the deck height was lower on the 68-71 460's along with HP heads made for a smaller combustion chamber therefore raising the compression ratios(approx. 9.0 to 1 thru 10.7 to 1), etc....

 

Ive done some searching and on the early 420/460 from 1968-71 the combustion chambers were 75cc and on the 1972 and up the chambers were 95cc. how will this affect my 1972 Lincoln MarkIV if i were to replace the current heads with a 1968-71 head or will the exchange not work well or should i have the combustion chamber increased.

Lets say i find a 1970-71 head should the combustion chamber be enlarged?

THANX EVERYONE FOR THE HELP!

 

Hot Rodders have been putting on heads with a smaller combustion chambers for years and it works very well. If you are using stock heads like C9VE's they will do just great but you will want to clean up the ports and remove the stock obstructions. Any reputable Engine Shop should be able to do them for a reasonable price. One last thing make sure that you have Induction Hardened Valve Seats and Stainless valves installed in the exhaust side of things so you don't burn out your valves, unleaded fuel can do some real damage to your engine if you don't take the right precautions when you rebuild.

 

Is there a block hugger/shortie exhaust header out there to fit a 460 under a lincoln hood? And does anyone know the specs on the stock cam out of the 1972 and 70-71 lincoln 460cid

 

Early castings on a 72 block with stock pistons will net about 9.5 to 1 C/R and about 9.3 to 1 on the 73 and ups as deck height was increased in 72 and in 73.

The heads are a bolt on but require the rail type rocker arms that came with them. The sled fulcrum stamped steel rocker will not work with the early castings.

http://www.reincarnation-automotive....omparison.html

The exhaust short turn is much higher in the later castings than the pre 72's and is a decent shape but needs to be lowered and rolled for best flow.

The ratings of 365 gross were optimistic and a more realistic number was about 320. hp as installed.

72 and up HP was measured at the end of the transmission with all accessory drives installed. The intake air temps were higher too.

Finally as the others have said: The exhaust ports on "EVERY" iron BBF sucl period. They are so bad that a baboon could make them better. Suffice to say with good port work intake and exhaust my ported D0VEs make 700 HP so they are a damned decent passenger car head once the emissions designed exhaust port is addressed.
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Be sure to use the earlier (pre-emissions) timing chain set. They put the timing "straight up" instead of retarded. You can't raise the ignition timing to counteract this. It's like degreeing a cam. Long story but trust me and go with the early style. You can find about 30-40hp there according to articles I have read.