Will today's premium gas handle this?

[67HEAVEN]

Until recently, I intended to "toss" my ZL-1/LS-7 "180" cam because of the realities of today's gasoline.

However, recent discussions have led me to believe that it may be possible to use it in my project after all.

Although I fully recognize the insanity and "ridiculousness" of using this on the street, I'm willing to suffer the slings-and-arrows of horrible driveability and the requirement of playing with the throttle at every stop light if it can be made to work on today's gasoline. Seriously! Driveability is not an issue. I don't mind working!!! I yearn to ride-the-monster again, if only on the street.

Those of you with SHP or HD big block experience........your opinion please on the likelihood of popping a hole in a piston using this cam, with approx. 11:1 compression, and well-ported open-chamber aluminum heads with today's pump premium.
SPECS HERE

Opinions?

 

[396 RAT]

Just curious, what are you building?
427? 454? 468? 502? 533?..............
Cant help with the cam question.
Have an L72 in mine, as the 65 396 cam
has not been around since the 60's.

 

[67HEAVEN]

Just curious, what are you building?
427? 454? 468? 502? 533?..............
Cant help with the cam question.
Have an L72 in mine, as the 65 396 cam
has not been around since the 60's.

Hi Mark,

We're close to decision time and it beginning to look like it'll be a 540.

 

[396 RAT]

Well, for what its worth.
The larger the engine the less radical the cam (feels)
You may get away with it?
Sounds like a real torque monster (540)
Sure your gonna spin it into the 6000-7000 rpm range?
I mean, that cam works best at higher rpm? dosent it?
How fast can you spin up a 540?

 

[RedRagTop]

My brother uses Sunoco 94 in his 427 1968 and adds both octane boost and lead additive. Seems to work OK and he has the high-comp heads...

 

[67HEAVEN]

My brother uses Sunoco 94 in his 427 1968 and adds both octane boost and lead additive. Seems to work OK and he has the high-comp heads...

That's one thing I don't want to do anymore. My years of running carting cans of AV. Gas and mixing Octane Boost are long over.

 

[67HEAVEN]

Well, for what its worth.
The larger the engine the less radical the cam (feels)
You may get away with it?
Sounds like a real torque monster (540)
Sure your gonna spin it into the 6000-7000 rpm range?
I mean, that cam works best at higher rpm? dosent it?
How fast can you spin up a 540?

Mark,

I'm serious when I say, I don't mind working it through traffic. At my advanced age, I won't be doing any stop-light running, so if the fart-can Honda next door pulls me across the intersection, I'll just smile.......that's if he can get over his car vibrating beside me during the red. :Silly

Most of what I'm doing, this time around, is purely for the senses anyway.
Feel........rattling those back teeth at idle.
Hearing.......YIKES.....what an idle!!!!
Sight.......Holy Crap, how wide are those tires on that '67? :eek
Smell.......that rubber burning.

Now, if I can just keep from stalling.

 

[PTighe]

The gas station down in town sells "Cam Two" 110 octane racing fuel, I bet that would work. The pump only has a 3 foot hose to pump it into a can though. At $3.50 a gallon, there doesn't seem to be a shortage of customers for it. :s

 

[Hib Halverson]

Those of you with SHP or HD big block experience........your opinion please on the likelihood of popping a hole in a piston using this cam, with approx. 11:1 compression, and well-ported open-chamber aluminum heads with today's pump premium.


Opinions?

If you plan to run this engine near or at WOT, likelihood of that happening is certain.

You need to either lower the compression a full point, use a conservative spark curve and keep the coolant temperature around 180-200 or you need a mix of pump and racing gasoline to have 95 or so octane.

 

[67HEAVEN]

Re: Re: Will today's premium gas handle this?

If you plan to run this engine near or at WOT, likelihood of that happening is certain.

You need to either lower the compression a full point, use a conservative spark curve and keep the coolant temperature around 180-200 or you need a mix of pump and racing gasoline to have 95 or so octane.

Here's the current availability in this neighbourhood:

Sunoco Ultra: 94
Sunoco Supreme: 92
Sunoco Plus: 89.5

Formula Shell Gold: 91
Formula Shell Silver: 89
Formula Shell Bronze: 87

Esso Supreme: 91
Esso Extra: 89
Esso Regular: 87

PJ67........110 octane!!! Lemme see. At $US3.50 a gallon that's $CA5.40 a U.S. gallon......approximately $6.50 a Canadian gallon. YIKES! And, at approximately 8 miles per gallon..........10 hour trip from here to Carlisle....... :crazy

 

[396 RAT]

I run stock 11-1, with the stock Ti retarded on "Ca". prem 91
Works OK. No knocking or pinging.
But agree 10-1 may be a better bet.
And not sure if your 540 can take advantage
of your cam unless it can spin into the
5000-7000 rpm range.?
(not sure, as in- I don't know)
They sell 100 octane down the street
at the 76 station for a mere $4.89 a gallon.
Add a few gallons now and then, but cant
Keep the car on a steady diet of it.
It does seem happier though?

 

[66427-450]

My replacement engine, a 468, has a true 10.7 static, alum heads, .036 quench, all sharp edges removes from piston faces and chambers. cam dur is 256/266@50, 850 DP jetted 82/84.

I'm planning on using pump gas. Key items: alum heads, tight quench, no sharp edges, radical cam

And plenty of guys run higher compression than 10.7 with pump gas and a similar setup. It can be done.

 

[iron cross]

Until recently, I intended to "toss" my ZL-1/LS-7 "180" cam because of the realities of today's gasoline.

However, recent discussions have led me to believe that it may be possible to use it in my project after all.

Although I fully recognize the insanity and "ridiculousness" of using this on the street, I'm willing to suffer the slings-and-arrows of horrible driveability and the requirement of playing with the throttle at every stop light if it can be made to work on today's gasoline. Seriously! Driveability is not an issue. I don't mind working!!! I yearn to ride-the-monster again, if only on the street.

Those of you with SHP or HD big block experience........your opinion please on the likelihood of popping a hole in a piston using this cam, with approx. 11:1 compression, and well-ported open-chamber aluminum heads with today's pump premium.
SPECS HERE

Opinions?

93 or 94 will work just fine. The compression ratio would limit the octain. 11-1 is still ok with pump gas. 12 or over you will need some special gas. A true crate LS7 is over 12-1 as is the L88`s.

 

[67HEAVEN]

Thanks for your input, everyone. More opinions welcomed.

I found an interesting page related to this discussion. Here's a teaser...

" The two flames collide causing an explosion and the infamous "pinging" noise so familiar to us. (Note: The pinging noise is the result of the cylinder wall vibrating like a guitar string due to the explosion)."

I confess to never fully understanding what the pinging sound actually was. Cylinder wall vibration....... :eek

http://www.aera.org/Members/EngineTech/engine.htm
-------------------
And, another link with another teaser......

"So what are the benefits of all this squishing and quenching? The benefits are small, but often important. Pump-gas engines that run on the ragged edge of detonation, for example, can greatly benefit from a tighter piston-to-head clearance to reduce rattle. That sounds contradictory since increasing compression should lead to increased detonation. All the engine builders we spoke to mentioned that tightening the quench (reducing the piston-to-head clearance) to get it under 0.050 inch will increase the static-compression ratio, but this tighter clearance also creates a more powerful squish effect. This additional turbulence creates a more homogenous 'soup' in the chamber, reducing the harmful effects of lean air/fuel ratio pockets. With all other variables being equal, this contributes to creating an engine that is less prone to detonation."

http://www.chevyhiperformance.com/techarticles/94138/
-------------------

Keep the info coming.