Crane Cams is BACK!!!

[Clem Z.]

Re: Crane Cams is BACK!!!

Comp Cams' advertising guys would like you to believe that they invented and developed the beehive valve spring, but they didn't. The beehive springs were developed by Mahle - we used them as OEM on the Viper V-10 beginning in 2002.

i had heard they were developed by GM back in the 80s as the LS engines have had them since 97. comp cam claim is they use oval shaped wire for better spring life and higher lift. i remember 40 years ago they had a beehive shaped spring BUT they used them upside down so you could use a larger diameter spring without cutting the spring pockets in SBC heads

[Joe C.]

Re: Crane Cams is BACK!!!

i had heard they were developed by GM back in the 80s as the LS engines have had them since 97. comp cam claim is they use oval shaped wire for better spring life and higher lift. i remember 40 years ago they had a beehive shaped spring BUT they used them upside down so you could use a larger diameter spring without cutting the spring pockets in SBC heads

The spring pocket OD on the 461 head needs to be enlarged by .004 in order to accommodate the 26918 spring. Obviously the designers of the early double humps were anticipating the arrival of this spring, used for the LS engines.

You are absolutely right about the oval cross sectional wire, and this particular spring will safely accommodate (1.850 - 1.260) 0.590 lift. At max allowable lift before coil bind, it is only 302 pounds over the nose.

[Gene M.]

Re: Crane Cams is BACK!!!

What is all this talk about twisting a 327 to 7 grand? We do not run our expensive toys to these extremes. A short blast to 6 grand is about all they would ever get. As in winding out first or second gear. So having a cam to wind 7 grand is unrealistic. Street engine Corvettes are (based on our ages) driven with some respect.

This is my opinion as I wouldn't beat on my cars. They are not race cars they are enjoyed on the streets. So camshafts designed for wide torque curve in the 2000 to 5500 grand range are my interest.

[Dick W.]

Re: Crane Cams is BACK!!!

What is all this talk about twisting a 327 to 7 grand? We do not run our expensive toys to these extremes. A short blast to 6 grand is about all they would ever get. As in winding out first or second gear. So having a cam to wind 7 grand is unrealistic. Street engine Corvettes are (based on our ages) driven with some respect.

This is my opinion as I wouldn't beat on my cars. They are not race cars they are enjoyed on the streets. So camshafts designed for wide torque curve in the 2000 to 5500 grand range are my interest.

I am just the opposite Gene, I twist the h**l out of my engines, they were made to run, they have good parts in them, enjoy them. I have never put one of my cars on a "pedestal" just to look at. If it redlines at 6,500, it should turn at least 7,000 if not 7,500 rpms.

I love the sound of a small block at 7,500 rpms in the morning

[Duke W.]

Re: Crane Cams is BACK!!!

What is all this talk about twisting a 327 to 7 grand? We do not run our expensive toys to these extremes. A short blast to 6 grand is about all they would ever get. As in winding out first or second gear. So having a cam to wind 7 grand is unrealistic. Street engine Corvettes are (based on our ages) driven with some respect.

This is my opinion as I wouldn't beat on my cars. They are not race cars they are enjoyed on the streets. So camshafts designed for wide torque curve in the 2000 to 5500 grand range are my interest.

It depends on the owner. Some owners of SHP/FI small blocks want "more power". Power is the product of torque and revs and since torque is basically a function of displacement and CR, the only way to get "more power" is to make the engine aspirate better at very higher revs. (You could also follow the Doc's method of just stuffing 500 CID into a numbers matching 283 block, but it's pretty pricey way to go.)

This is what the "327 LT-1" is all about. Massage the heads, install high strength connecting rods and a LT-1 cam, and it makes about equal low end torque to a Flint-built L-79 with more top end power than a Flint built 30-30 cam engine. Peak power arrives at about 6500 with only a slight rolloff to 7000 and the first signs of valve float with the OE springs occurs at about 7200, so I established 7000 as a practical redline. The upgraded rods eliminate the Achilles Heel of these early SBs, so you can buzz it to 7000 as often as you like without any decrease in OE reliability.

One owner - a young commercial pilot - revs his to 7000 everytime he drives it, and once cranked the speedometer off the scale (with a 3.36 gear and W-rated tires). Been there, done that, but I came to grips with my mortality twenty years ago.

In our youth most of us craved this type of engine and probably engaged in some insane driving, but now that most of us are middle age or older, a bit more docile engine is more suited to our driving preferences and style.

The 300 HP engine is very docile and has stump pulling low end torque. That's great, but it runs out of breathe at 5000.

So I came up with the "Special 300 HP" configuration with the "McCagh Special" camshaft, head massaging and upgraded rods similar to the "327 LT-1". It still idles butter smooth at 500, has stump pulling low end torque, but makes Flint-built L-79 top end power and revs, so you have the best of both worlds in a bulletproof package.

You can have it anyway you want - a high rev screamer that will still easily pull from 1000 revs in top gear with a 4.11 axle, or a stump puller that will still be pulling strong at 6000. Your choice.

Duke

P. S. One of the "327 LT-1" engines that originally started as a L-79 received the NCRS Top Flight award, and a "McCagh Special" cammed engine received a Duntov award.

[Gene M.]

Re: Crane Cams is BACK!!!

Duke say it realistically, 6 grand is what a NCRS street 327 turns, after that it's just a bunch of rev's and noise. Power and torque are well out of the 327's power range at 7 grand.

The stock rods are a hope and prayer at 7 grand. Your just flirting with a boat anchor at that rpm.

Any body that wants to twist their vette to the stratosphere is welcome to. Have at it. Do what you want. But don't tell me it's worth while doing.

[Duke W.]

Re: Crane Cams is BACK!!!

Hello?
Is there anybody in there?
Just nod if you can hear me.
Is there anyone at home?

-Roger Waters, "Comfortably Numb"
from The Wall album by Pink Floyd, 1979

[Donald O.]

Re: Crane Cams is BACK!!!

Hello?
Is there anybody in there?
Just nod if you can hear me.
Is there anyone at home?

-Roger Waters, "Comfortably Numb"
from The Wall album by Pink Floyd, 1979

And this aids in the discussion of Crane Cams how?

Don

[Duke W.]

Re: Crane Cams is BACK!!!

The Crane cams discussion ended at post #12. Ahhh, let's see... Your post is #54 and this one is #55.

Duke