C2 Big Block questions

[IH2LOSE]

I just recently took the 66 out for a spin 427/425 4 spped 4:11s and stock configuration with the exception of an MSD distibutor and box (I have this is the car as I am saving to have my distributor rebuild by Dave feilder) anyways I am slightly retarded on my timing so I can run pump gas.And I have radial tires on the car.

So I take the car out and allthough I am limited by traction,this car plants you in your seat, I mean you know you are driving a muscle car. I cant describe it but it makes you breath heavy,This car burns all gears No problem.and its scary fast.

Now I have my 62 that is also limited by traction and I am running a 454 ho gm performance crate motor that I thought had a simular HP and torque range of the L72 in the 66 and has the 700R4 trans in it with 3:54 gears in it and when I did some calculations (I forgot where I did the calculations or who posted the link to it) the 62 was geared lower in first and secound gear.

So now onto my question

As I stated the 62 is limited in traction but its just not scary fast like the 66.Its power just doesnt come on as strong. Now dont get me wrong the 62 goes good as a matter of fact so good it will burn 3rd gear with the sloppy automatic thats in it,

So I am just wondering what makes these 2 cars feel so different ? Is it the M21 4 speed compaired to the auto trans

I have to look at the carb on the 66 its the correct carb that I know is dual feed but I have to look if its mecanical or vacum secoundaires and thats what makes the 66 feel like its pulling so much harder then the 62.

I am just perplexed on this as both cars are rated at the same horse power.

Now if I never drove my 66 I would think the 62 was the quickest & fastest car I ever owned but when compairing it to the 66 its not as thrilling to drive

 

[studiog]

Hi Larry,
My theory: You are in total control of the thrill when you drive the 66 4 speed. In the 62 you are just pushing the go pedal and going along for the ride. I know that is over simplifying but I was never happy with any automatic Vette I owned, (just my personal preference).

 

[Viet Nam Vett]

It's funny tou posted this because my 502 is kinda like you discribed your 454.

I have yet to really jump on it in first..off the line .. but I have nailed it after the shift to second..and to be honest.. it doesn't come on like a dropped rock... I mean it pushes you back in the seat and hits the rev limiter real fast but it doesn't have that kick you would expect when you nail it.

I'm running the stock 3:36 rear and the Keisler with the 3:27 first. I'm going to order one of those spring kits for the Vaccume Secondaries and re-check the timing and advance.

I think it's just a case of revisiting the above and to make sure everything is set correctly. Is your 454 using the Holley with the Vaccume Secondaries..?? If so...a spring kit may be in the offering..

 

[Wilkinshc]

I wonder if it ain't the difference in power band, your crate motor should have a broader power band as opposed to the higher ( top end power) of the 427. Also did the c-2 seem to have better traction? I would think it would have better traction which would you feel in the seat of your pants.

Just my opinion.

Chuck

 

[Kid_Again]

It's funny tou posted this because my 502 is kinda like you discribed your 454.

I have yet to really jump on it in first..off the line .. but I have nailed it after the shift to second..and to be honest.. it doesn't come on like a dropped rock... I mean it pushes you back in the seat and hits the rev limiter real fast but it doesn't have that kick you would expect when you nail it.

I'm running the stock 3:36 rear and the Keisler with the 3:27 first. I'm going to order one of those spring kits for the Vaccume Secondaries and re-check the timing and advance.

I think it's just a case of revisiting the above and to make sure everything is set correctly. Is your 454 using the Holley with the Vaccume Secondaries..?? If so...a spring kit may be in the offering..

OK, you asked for it.....

ROLLER ROCKERS

 

[Viet Nam Vett]

OK, you asked for it.....

ROLLER ROCKERS

Roller Rockers...... Or a 572.....

 

[wallyknoch]

Several factors are different in the 66 L72 than in the 454 HO. To start with, gear ratio of a 4.11 in the 66 as to a 3.54 in the 62. The 62 may run a buck fifty, but the 66 will get there a lot quicker even with a faster shifting auto in the 62. But here is where you lose it. Camshaft, and compression in the L72 will eat up most 454`s with there lower compression and low winding hydraulic camshafts unless it`s a LS7 454. The L72 is nearly 3 full points higher than a 454HO in compression and a much better high winding solid lifter cam. As a result the L72 is a much better performance engine than most 454`s and even the 502`s thats the basic reason why the 66 is a much better runner.

 

[grumpyvette]

wallyknoch is correct! THE COMPRESION RATIO CAM TIMING , TYPE OF CAM,AND REAR GEARING are TOTALLY differant, between the two engines, you want that crate motor to sing the same tune ?? it will need a boost in compression, a cam change and those 4.11 rear gears, but if your going to do all that ID seriously suggest swapping in a 4.25" stroker crank to make that 454 a 482 or with a slight over bore a 489 or 496, which makes boosting the effective cpr to between 10.8 and 11:5 (for low octane gas)(it runs better with 12:1 cpr)easier with a lower piston dome height, and installing a solid lifter cam like a #3959180 chevy CAM

that was a very comon combo in the mucle car days that flat KICKED BUTT---with about 500ft lbs and 500hp, YEAH WATCH/CORRECT the CLEARANCES DURRING THE ASSEMBLY PROCESS, and DO some port and bowl clean up work on the heads

BTW heres the modern updated version (below and in a 496 the effective rpm range is noticably lower due to the increased stroke/displacement)

http://www.cranecams.com/?show=browseParts&action=partSpec&partNumber=134761&lvl=2&prt=5

 

[Wilkinshc]

Camshaft, and compression in the L72 will eat up most 454`s with there lower compression and low winding hydraulic camshafts unless it`s a LS7 454.

Don't forget your ZL1 and ZL1 Ramjet

#110

 

[vintagecorvette]

IH2LOSE,

I have followed your build and I have a question. You are a mechanical guy who just built a Rod from the ground up, Why would you send something as easy as a distributor out to be rebuilt. I am lucky and have an uncle who has a Sun distributor machine, but I am not certain if it really matters. i have seen pix of your 1966 and it is beautiful as are the rest of your rides, will this fellow really do that much to the distributor?

Just Curious. oWEN

(I have this is the car as I am saving to have my distributor rebuild by Dave feilder)

 

[IH2LOSE]

Owen.

There are some thing I feel are better left to a Pro, I dont understand how a TI system works. I dont have the test or diagnostic tools needed to test every thing. Thats why I chose to enlist the servies of a pro.

There are alot of things I will learn to repair/rebuild, but something like this (I wont be rebuilding a ti distributor ever again)I will never have to do again so its better for me to find the best guy I can use for the job.

I am not really too lazy to get an education on them,I just feel its not worth my effort because I will never have to rebuild one again Its the same thing with carburators,Yes I can do them but for me its always better to send them out to a "real" rebuilder

 

[IH2LOSE]

thank you all for the input. what your saying makes sence about the different motors, but isnt hp just hp and torque just torque. they boh seam to have the final power band/engine hp profile ?

I originally wanted to build a ls6 performance crate motor for his car but was told by an engine builder the block had issues

And yes Wally the 62 will get waay up into he triple digits real quick as a matter of fact alot quicker then the wifes C5,if you wer a nice guy Wally you would have shaired one of the many
L88 motors you have sitting under the bench in your shops's

And thanks for the specs grumpy,I will see I can send you he specs to my motor because when I do the swap to the tri power i want to re-cam he motor to add a little lope/rump to the car, right now the wifes suv sounds like it has a hotter cam in it

 

[wallyknoch]

L72`s are tough to Beat

Larry you dont need a L88 or a ZL1. In fact those are 427`s. You cannot expect too much from a low compression hydraulic cammed 454 or even a 502 for that matter. All my answer was, is to indicate just how really good a L72 powered Vette can be. One of the best mass produced single 4 bore engines by any company. Remember that originally they were rated as 450HP which was probably low so as not to really scare a new 66 Vette purchaser. This engine was also used in all the COPO, Berger, Yenko and the rest of the dealer installed Camaros and Chevys including myself.

By the way, Happy New Year

 

[67HEAVEN]

Larry you dont need a L88 or a ZL1. In fact those are 427`s. You cannot expect too much from a low compression hydraulic cammed 454 or even a 502 for that matter. All my answer was, is to indicate just how really good a L72 powered Vette can be. One of the best mass produced single 4 bore engines by any company. Remember that originally they were rated as 450HP which was probably low so as not to really scare a new 66 Vette purchaser. This engine was also used in all the COPO, Berger, Yenko and the rest of the dealer installed Camaros and Chevys including myself.

By the way, Happy New Year

Did you have to start this thread, Larry?

Way in the back of my brain sits that little ol' "180" ZL-1 cam from my 427. Actually, it's in the attic of my garage.

If there is one thing I miss about the old engine........it's the "feel" of that cam. Wicked is the only word that sums up the idle and "WOW!!!" is what happens when you get on it hard.

So, here I am getting ready to tackle my winter projects on the car (steeroids, windshield rubber, etc.) and now I'm thinking............."Hmmmm".

Like I said.......did you have to start this thread, Larry?

 

[Viet Nam Vett]

Did you have to start this thread, Larry?

Way in the back of my brain sits that little ol' "180" ZL-1 cam from my 427. Actually, it's in the attic of my garage.

If there is one thing I miss about the old engine........it's the "feel" of that cam. Wicked is the only word that sums up the idle and "WOW!!!" is what happens when you get on it hard.

So, here I am getting ready to tackle my winter projects on the car (steeroids, windshield rubber, etc.) and now I'm thinking............."Hmmmm".

Like I said.......did you have to start this thread, Larry?

Ok..Stop Right Here........... Call Stepinwolf....Get the name of his GM Dealer and have him get you a Price on a 572.......and stop with the..I'll Do This ..and I'll Do That.... Cam ..Shmaaaam....gack.

Just change out the Motor and be done with it...

 

[67HEAVEN]

Cam ..Shmaaaam....gack.

Just change out the Motor and be done with it...

My Dear VNV,

Apparently you've never experienced that ZL-1 cam (and related changes to take advantage of its capabilities ).

I do know what I had to do to my L-71 to make that cam work. Now, I'm wondering what I'd have to do to the ZZ-502. Hmmmm?

It never ends. :crazy

Happy New Year

 

[67HEAVEN]

I do know what I had to do to my L-71 to make that cam work. Now, I'm wondering what I'd have to do to the ZZ-502. Hmmmm?

Allow me to think out loud for a moment.

To use the ZL-1 cam in the L-71, I had to notch the 11.0:1 pistons. I also used the L-88 triple valve springs and larger valves while performing many hours of porting and polishing in the compression chambers and intake and exhaust ports on the cast heads. We also surfaced the heads, and with a thinner head gasket, got close to 11.5:1 compression. Those changes, combined with a Tarantula Torker intake and Holley 850 double-pumper......well, the change was phenomenal, to say the least. :crazy

So, what is required to achieve similar improvements with the 502. I'm convinced that the heads are plenty good already, including the valve train. Piston notching would not be required. I'm already running "plenty" of intake and carburetion.

There is the issue of returning to mechanical lifters.

Hmmmm. :confused

I've said this before, but it's true. The main thing I miss from the old 427 is the massive idle. I mean it. If you haven't heard a ZL-1 idle......think Super Stocker at the line. Just look at the specs for the 3959180 cam in the chart grumpyvette posted a page back.

The car already gets plenty of these ( :eek ) at every stop light.



I just want these.......

Help. Someone stop me. :cry

 

[Viet Nam Vett]

My Dear VNV,

Apparently you've never experienced that ZL-1 cam (and related changes to take advantage of its capabilities ).

I do know what I had to do to my L-71 to make that cam work. Now, I'm wondering what I'd have to do to the ZZ-502. Hmmmm?

It never ends. :crazy

Happy New Year

My Dear 67 Heaven....And A Happy New year to You..Too..
No..I have not had the pleasure of feeling the extra 20 to 50 what ever HP Increase from the ZL-1 Bump Stick... But I have had the pleasure of feeling what 650HP feels like a few years back in a friends car..

Now if you like ripping out the rad and related gack to get at the bump stick and you have time on your hands ..very cool. ..

When I started on my project I asked my self....Self....How much HP do you want... Self said... Heh 502 Cube-bies would be nice and what ever I get at the rear wheels will do. Now Self knows that more HP will be more gack that that you have to add to handle more power. So..self decided to limt the HP and not have to add Gonzo rear end components and related stuff.

I also know that you have done that so you are ahead of the game. So adding more HP will be fun.

Self ..also decided that down the road...in about what ever years when he gets tired of the 502... That self would rip it out and put in a bigger and better more HP drive line rather then piece meal parts to add the HP on the old Rat Wagon.

To some it all up... I look forward to your Bump Stick Insatll which I know you will Photo Document here. Also ...Some base line Dyno and after Dyno would be nice to see.

So..in a sense..you can say that your project will be the After Birth of The Rebirth Of A Legend....
:L

 

[grumpyvette]

If you read what I posted carefully.... youll see that ZL1 solid lifter flat tappet cam was suggested as correct for a HIGH COMPRESSION 4.25" stroker combo in the 482-496 displacement range, installed in your 454s block WITH the matching rear gear ratio ETC.
as always its about the total COMBO ,you can,t expect to install a cam like that in the low cpr 454 and get anything like a decent combo

 

[IH2LOSE]

Like I said.......did you have to start this thread, Larry?

You know I guess the cars are really never done. The motor portion of the project was a minor problem for me i had a Ls6 performance crate motor i was sitting on for years for this project and had to get the crate motor last minute after i found out the ls6 block had some issues.

I am going to do a cam change when I install the tri power set up. As we get closer to doing that I will look for some cam recomndations from the forum