L72 vs L36 What's a better driver?

[doug lyle]

I'm looking to buy a big block coupe and could use a little advice. What engine is better for steet driving? I've heard varying accounts of what motor is better. Some people tell me the L36 will run worse on pump gas than the L72. I realize I'll probably need a lead type additive to boost octane levels and will possiby need to add hardened valve seats. Besides fuel requirements I'd just like to know what motor is a better driver and why? I've read all the books and know about specs, solid vs. hydraulic cams, 4 and 2 bolt mains, etc. I would really appreciate hearing from people who own and drive with these engines. I plan on driving this car so drivability is very important.

And if you're selling one of these please contact me.
thanks, Doug 408-593-7375

[Joe L.]

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

Doug-----

I can tell you this: I was once the original owner of both a 1966 Chevelle SS396 with 360 hp (L-34) engine and a 1968 Chevelle SS396 with 375 hp (L-78) engine. The L-34 is virtually identical to the Corvette L-36 except for displacement. The L-78 is virtually identical to the Corvette L-72 except for displacement. I can tell you for absolute certain that the L-34 was a FAR, FAR better street engine than the L-78. Hands down. Absolutely positively.

[Joe L.]

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

Doug-----

I can tell you this: I was once the original owner of both a 1966 Chevelle SS396 with 360 hp (L-34) engine and a 1968 Chevelle SS396 with 375 hp (L-78) engine. The L-34 is virtually identical to the Corvette L-36 except for displacement. The L-78 is virtually identical to the Corvette L-72 except for displacement. I can tell you for absolute certain that the L-34 was a FAR, FAR better street engine than the L-78. Hands down. Absolutely positively.

[doug lyle]

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

Thanks for the input. What traits made the L34 better?

Thanks, Doug

[doug lyle]

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

Thanks for the input. What traits made the L34 better?

Thanks, Doug

[Joe L.]

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

Doug----

The profile of the hydraulic lifter camshaft used for the L-34/L-36 made for a better street engine than the much more radical solid lifter grind used in the L-72/L-78. Also, the oval port cylinder heads of the L-34/L-36 made for better torque in the ranges that would be used for street driving as compared to the larger rectangular ports used for L-72/L-78. Taken together, these 2 factors were the biggest reasons for the better driveability of L-34/L36.

[Joe L.]

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

Doug----

The profile of the hydraulic lifter camshaft used for the L-34/L-36 made for a better street engine than the much more radical solid lifter grind used in the L-72/L-78. Also, the oval port cylinder heads of the L-34/L-36 made for better torque in the ranges that would be used for street driving as compared to the larger rectangular ports used for L-72/L-78. Taken together, these 2 factors were the biggest reasons for the better driveability of L-34/L36.

[John R.]

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

Doug, I have an early 67 L36 coupe with A/C and can tell you from personal experience that it drives better around town than the L72. I have had no problem with pump gas, use the A/C in our hot summer weather without overheating and really enjoy the performance I get out of this engine. I also have no problem adjusting the carburetor to pass our Arizona emissions testing requirements which I did last week. Joe is absolutely correct about the original cam in this engine. I was a little disappointed when I first acquired the car that it was not an L72 but can now say without hesitation that I am delighted with the way it drives.

[John R.]

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

Doug, I have an early 67 L36 coupe with A/C and can tell you from personal experience that it drives better around town than the L72. I have had no problem with pump gas, use the A/C in our hot summer weather without overheating and really enjoy the performance I get out of this engine. I also have no problem adjusting the carburetor to pass our Arizona emissions testing requirements which I did last week. Joe is absolutely correct about the original cam in this engine. I was a little disappointed when I first acquired the car that it was not an L72 but can now say without hesitation that I am delighted with the way it drives.

[Barbara S.]

L36!

Back in the '80's, I owned a 66 L36 car and loved it. It was a great driver. Man, I miss that car!

Tony

[Barbara S.]

L36!

Back in the '80's, I owned a 66 L36 car and loved it. It was a great driver. Man, I miss that car!

Tony

[John M.]

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

Doug,
I drove a 66 L72 this past summer and it was an awesome machine. Get it over 3000rpm and hold on. I have a 69 L71 and it's very fast and quite reliable. It has let me down once since 1998, over 15,000 miles,and that was just the starter. The L36 is really nice too but if you want mean get the L72. The fuel is a problem in both but more so in the L71,72s

[John M.]

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

Doug,
I drove a 66 L72 this past summer and it was an awesome machine. Get it over 3000rpm and hold on. I have a 69 L71 and it's very fast and quite reliable. It has let me down once since 1998, over 15,000 miles,and that was just the starter. The L36 is really nice too but if you want mean get the L72. The fuel is a problem in both but more so in the L71,72s

[Duke W.]

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

The L-36 has a smooth 500 RPM idle and gobs of low end torque. The L-72 has a somewhat nervous 8-900 RPM idle and "comes on the cam" about 3500-4000. Overall the L-72 is a lot more "edgy" while the L-36, even with a 3.08 axle is docile and easier to drive in traffic.

These different characteristics define medium performance and Special High Performance engines, and the comparison is also applicable to the medium performance small small blocks versus their SHP cousins.

In our youth having a "big cam" made a macho statement, but as we age I think most of us appreciate the more tame characteristics of medium performance engines - or maybe we've been spoiled by modern engines with their near perfect driveability.

Case in point - I reindexed the cams in my Cosworth Vega three years ago, retarding the inlet 8 degrees and advancing the exhaust 8 degrees to eliminate the excess overlap that was designed in to control NOx. (The valve timing is now essentially identical to the L-79 cam.) With the high overlap the best idle I could get was 1200@12", and it sounded like a V-8 with a Duntov cam. Now the idle is 900@18" and it sounds like a tractor engine, but it is so much more docile and easier to drive in traffic with both more low end torque and more top end power.

NOx emissions doubled in my last test, but they are still only one-half the limit.

Duke

[Duke W.]

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

The L-36 has a smooth 500 RPM idle and gobs of low end torque. The L-72 has a somewhat nervous 8-900 RPM idle and "comes on the cam" about 3500-4000. Overall the L-72 is a lot more "edgy" while the L-36, even with a 3.08 axle is docile and easier to drive in traffic.

These different characteristics define medium performance and Special High Performance engines, and the comparison is also applicable to the medium performance small small blocks versus their SHP cousins.

In our youth having a "big cam" made a macho statement, but as we age I think most of us appreciate the more tame characteristics of medium performance engines - or maybe we've been spoiled by modern engines with their near perfect driveability.

Case in point - I reindexed the cams in my Cosworth Vega three years ago, retarding the inlet 8 degrees and advancing the exhaust 8 degrees to eliminate the excess overlap that was designed in to control NOx. (The valve timing is now essentially identical to the L-79 cam.) With the high overlap the best idle I could get was 1200@12", and it sounded like a V-8 with a Duntov cam. Now the idle is 900@18" and it sounds like a tractor engine, but it is so much more docile and easier to drive in traffic with both more low end torque and more top end power.

NOx emissions doubled in my last test, but they are still only one-half the limit.

Duke