Author Topic: 140 cam, manifolds, and cross ram????  (Read 11513 times)

aaronz28

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140 cam, manifolds, and cross ram????
« on: June 22, 2006, 02:39:27 PM »
i'm seeing alot of z's restored with the new crossram, 140 cam, and exhaust manifolds with smog.

i love the idea, but can't believe that it runs better than the 30-30 cam with single 4bbl on the street with manifolds.
I've got the stock parts on my car and have been thinking of doing the crossram swap, but curious to know if others have gone this route and kept the manifolds on the car?

can anyone speak to this?

thanks

aaron

JohnZ

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Re: 140 cam, manifolds, and cross ram????
« Reply #1 on: June 22, 2006, 03:18:43 PM »
The cross-ram setups are great for "bling" at cruise-ins, but are very difficult to tune for street use, especially with the -140 cam, and have even less low to mid-range torque than a stock DZ with the "30-30" cam, which doesn't have much to start with. Seems like a LOT of money for "show-off" points, especially with the driveability compromises it brings. To each his own, but I wouldn't bother.
'69 Z/28
Fathom Green
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aaronz28

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Re: 140 cam, manifolds, and cross ram????
« Reply #2 on: June 22, 2006, 07:33:10 PM »
john.
since i have to remove the heads anyway, i was thinking of swapping cams while im at it. do you know of another cam that will work better than the stock cam ? considering that im keeping my manifolds and smog.

ive never abeen a fan of the lt1. but people seem to like it. aside from the LT1 cam. what might you suggest? or would you leave it alone?
thanks
aaron

3Zs

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Re: 140 cam, manifolds, and cross ram????
« Reply #3 on: June 22, 2006, 10:35:18 PM »
Aaron, I agree 100% with John Z.  If you are going to do much driving, you will find that the "140" cam and crossram is "all show and no go".  This set-up has no vacuum, no power under 4000 rpm and will be constantly in need of tuning.  The stock exhaust manifolds will only make the problem worse.  I have two Zs with the "140" cam and cross-ram, but both have headers and non-restrictive exhaust systems.  In addition, they both have "K-66" ignition.  Both cars are very tempermental, hard to start, won't idle under 1200, and would probably be outrun on the street by a good-running single four barrel car with a 30-30 cam and stock exhaust.  But they sure look and sound cool!  These cars are rarely driven, so I wouldn't consider putting them back stock.  My two cents.  Tex Timberlake

red69

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Re: 140 cam, manifolds, and cross ram????
« Reply #4 on: June 23, 2006, 02:18:17 PM »
Tex
What are you running for fuel in your crossram cars? I had fits with mine until I fed it good gas. Never will have low end but idles and runs great. Pat

JohnZ

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Re: 140 cam, manifolds, and cross ram????
« Reply #5 on: June 23, 2006, 03:05:39 PM »
john.
since i have to remove the heads anyway, i was thinking of swapping cams while im at it. do you know of another cam that will work better than the stock cam ? considering that im keeping my manifolds and smog.

ive never abeen a fan of the lt1. but people seem to like it. aside from the LT1 cam. what might you suggest? or would you leave it alone?
thanks
aaron

The factory LT-1 cam will produce about 20% more low-to mid-range torque than the "30-30" and gives up very little at high rpm. The beauty of the factory cams (other than the -140) is that they all use the same grocery-getter stock valve springs (3901168) as grandma's 307, and the stock valvetrain is proven bulletproof; no need for "Godzilla" valve springs, no problems with wiped cam lobes.
'69 Z/28
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aaronz28

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Re: 140 cam, manifolds, and cross ram????
« Reply #6 on: June 24, 2006, 04:41:34 AM »
so i can't imagine how these guys run the -140 with manifolds LOL...

aside from the Lt-1, which i have had experiance with, is there another cam that anyone uses in a DZ motor that has a similair idle to the 30-30 yet runs better?

i thought about just putting the 140 cam in and keeping the stock intake and carb, while boosting the compression, but i'm sure that would be worse than the 30-30, aside from the wicked idle...

do you really loose that much low end from the 140 to the 30-30 if keeping the stock intake and carb?

my car is geared with 4.10s and a M-22, but i'm considering an M-20 for better off the line street manners..

any thoughts?

Aaron

JohnZ

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Re: 140 cam, manifolds, and cross ram????
« Reply #7 on: June 24, 2006, 05:32:57 PM »
The -140 cam SUCKS for a street-driven car, especially with stock manifolds; it was designed for only one thing - running at WOT above 4000 rpm with headers and open exhausts, period. I'd stick with what you have.
'69 Z/28
Fathom Green
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aaronz28

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Re: 140 cam, manifolds, and cross ram????
« Reply #8 on: June 25, 2006, 01:56:28 AM »
yeah..., i had a friend with a Rallye Green 68 Z that had the 140 in it, with headers, stock intake and carb, 3.73 and m-21.... i didn't like it untill about 80 mph LOL...

i'm going to keep the 30-30, perhaps advance it 2-4 degrees, and enjoy it.

thanks

Aaron

dab67

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Re: 140 cam, manifolds, and cross ram????
« Reply #9 on: June 26, 2006, 04:57:38 PM »
JohnZ:  What would be the GM part number for the LT-1 cam? is it 3896962? or the 24502476?
db67

plumL78

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Re: 140 cam, manifolds, and cross ram????
« Reply #10 on: June 26, 2006, 09:43:00 PM »
I will admit that it likes to run in the high rpm range but I am speaking from only my experience. I have a cross ram and 140 cam with headers and stock dist.  and have driven stock z28s and they don't have the response and pull of mine. It starts and idles  like it shoud and runs like it shoud. I credit my brother who is a motor head for the tuning.  We've had it for 35 years.

JohnZ

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Re: 140 cam, manifolds, and cross ram????
« Reply #11 on: June 27, 2006, 04:12:50 PM »
JohnZ: What would be the GM part number for the LT-1 cam? is it 3896962? or the 24502476?
db67

The LT-1 cam is available from GM as P/N 12364054 (cam and lifter kit, manufactured by Crane), or from Federal-Mogul/Speed-Pro as their #KC-1145R (cam and lifter kit) or as #CS-1145R (cam only), or the cam only from Crane as their #969551.
'69 Z/28
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