L72 vs L36 What's a better driver?

[Steve Pettit]

Re: L72 vs L36 What's a better driver?

Doug.

I've got a 66 L36 and if you follow the timing map specifications in the archives you get very good results with pump gas, very good driveability with wonderful low end torque and it does haul a**. I've driven both, but it has been a long time since I drove the L72, and it was a real screamer at revs, but a pita going through town. I'd love to have one of each, but wouldn't trade my L36. This is one of those good problems, no wrong answer.

Regards
Steve

[Steve Pettit]

Re: L72 vs L36 What's a better driver?

Doug.

I've got a 66 L36 and if you follow the timing map specifications in the archives you get very good results with pump gas, very good driveability with wonderful low end torque and it does haul a**. I've driven both, but it has been a long time since I drove the L72, and it was a real screamer at revs, but a pita going through town. I'd love to have one of each, but wouldn't trade my L36. This is one of those good problems, no wrong answer.

Regards
Steve

[doug lyle]

Re: L72 vs L36 What's a better driver?

This is all really great information. Thanks to all that have posted. I don't know that I want a motor that makes it's power and torque in the higher RPM's. Maybe the L36 is better for street driving where most of the time the RPM's will be in the lower RPM's.
Doug

[doug lyle]

Re: L72 vs L36 What's a better driver?

This is all really great information. Thanks to all that have posted. I don't know that I want a motor that makes it's power and torque in the higher RPM's. Maybe the L36 is better for street driving where most of the time the RPM's will be in the lower RPM's.
Doug

[Everett Ogilvie]

L72 Hands Down !

I have never understood the claims that the L72 is harsh or too "peaky" for around town driving - this is nonsense. I have owned three, two with 3.36 gears and one with 4.11 gears. You tell me if this is "peaky" - I could put it in 4th gear and slow down to near idle speed (about 1200-1500 rpm), and get into the throttle hard and it would not bog (any of the three cars, regardless of the gears). It pulled pretty hard from 1500 rpm, and of course came on really hard as revs built. I am talking about a car pulling hard from 35 mph to 100+ mph, in one gear. This is a fairly extreme test of the carb set up, lugging it down to 1200 rpm. If you drive it "normally" you would never consider it problematic - the engine is so tractable that you can short-shift all the time, or even skip 2nd gear. The ONLY drawback to the L72 is if you retain the 11:1 compression you need some help with good (expensive) fuel. For those with L72s that don't make power at or below 2000 rpm - it either has the wrong cam, the carb is poorly set up, or the ignition timing and curve are not optimized.

[Everett Ogilvie]

L72 Hands Down !

I have never understood the claims that the L72 is harsh or too "peaky" for around town driving - this is nonsense. I have owned three, two with 3.36 gears and one with 4.11 gears. You tell me if this is "peaky" - I could put it in 4th gear and slow down to near idle speed (about 1200-1500 rpm), and get into the throttle hard and it would not bog (any of the three cars, regardless of the gears). It pulled pretty hard from 1500 rpm, and of course came on really hard as revs built. I am talking about a car pulling hard from 35 mph to 100+ mph, in one gear. This is a fairly extreme test of the carb set up, lugging it down to 1200 rpm. If you drive it "normally" you would never consider it problematic - the engine is so tractable that you can short-shift all the time, or even skip 2nd gear. The ONLY drawback to the L72 is if you retain the 11:1 compression you need some help with good (expensive) fuel. For those with L72s that don't make power at or below 2000 rpm - it either has the wrong cam, the carb is poorly set up, or the ignition timing and curve are not optimized.

[Michael H.]

Re: L72 Hands Down !

Everett, I agree 100%. The myth that a 425 HP is difficult to drive around town is incorrect. I've driven mine in just about every kind of driving situatition there is in the last 20 years and have never had a problem. We drove that car from Chicago to the Hoover dam and back for the NCRS event in 84 and never even opened the hood other than to check oil every 500 miles. I drive around town in traffic in temp's of 95 deg and it's never overheated. (close a few times tho) Absolutely dependable and trouble free. The cam in a 425 is not radical at all but still has that great sound at idle. Not for everyone but certainly not the flaming beast that some have made it out to be.

Michael

[Michael H.]

Re: L72 Hands Down !

Everett, I agree 100%. The myth that a 425 HP is difficult to drive around town is incorrect. I've driven mine in just about every kind of driving situatition there is in the last 20 years and have never had a problem. We drove that car from Chicago to the Hoover dam and back for the NCRS event in 84 and never even opened the hood other than to check oil every 500 miles. I drive around town in traffic in temp's of 95 deg and it's never overheated. (close a few times tho) Absolutely dependable and trouble free. The cam in a 425 is not radical at all but still has that great sound at idle. Not for everyone but certainly not the flaming beast that some have made it out to be.

Michael

[Duke W.]

Re: L72 Hands Down !

It's all relative. Both L-36 and L-72 have the same advertised peak torque, but L-36 reaches that level at 3600 versus 4000 for L-72, so L-36 makes more torque/power up to somewhere in the high 3000s and is definitely more docile in low speed driving. Above 4000 the L-72 is clearly stronger. The same applies when comparing medium performance and SHP small blocks. SHP engines both SBs and BBs should pull smoothly from about 1000, but they don't really get strong until over 3000. Medium performance engines will pull from under 1000 and are stronger up to the mid to high threes.

You and I prefer the characteristics of SHP engines, but they aren't for everyone, and many who have them and did not get hooked on them 40 years ago might prefer the operating characteristics of medium performance engines since their operating characteristics are closer to what we have come to expect from modern engines.

Duke

[Duke W.]

Re: L72 Hands Down !

It's all relative. Both L-36 and L-72 have the same advertised peak torque, but L-36 reaches that level at 3600 versus 4000 for L-72, so L-36 makes more torque/power up to somewhere in the high 3000s and is definitely more docile in low speed driving. Above 4000 the L-72 is clearly stronger. The same applies when comparing medium performance and SHP small blocks. SHP engines both SBs and BBs should pull smoothly from about 1000, but they don't really get strong until over 3000. Medium performance engines will pull from under 1000 and are stronger up to the mid to high threes.

You and I prefer the characteristics of SHP engines, but they aren't for everyone, and many who have them and did not get hooked on them 40 years ago might prefer the operating characteristics of medium performance engines since their operating characteristics are closer to what we have come to expect from modern engines.

Duke

[John M.]

Re: L72 Hands Down ! Right on, Everett! NM *NM*

[John M.]

Re: L72 Hands Down ! Right on, Everett! NM *NM*