Author Topic: Anyone run the LT1 (178) cam in their DZ302???  (Read 6970 times)

aaronz28

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Anyone run the LT1 (178) cam in their DZ302???
« on: July 17, 2009, 09:38:31 PM »
does anyone actually run the LT1 cam in the 302?

After going back and forth between day 1 and day 2  for my 1969 z... i've decided to keep it day 1 appearing..

the only thing i might consider is the slightly smaller LT1 cam as i've read that it was optimized for the logtype manifolds on these cars, whereas the 30=30 wasn't.

my car has wideratio muncie and 4.10s... but i want all the GO i can get..

i ran several Engine Analyzers programs using as accurate of info that I could find, and in every instance... when using stock heads, stock intake, and most importantly stock manifolds, with a restrictive exhaust... the LT1 showed the best torque and top HP (only beating the 30-30 by a few HP at 6500 rpm) 

i've run the 30-30 enough times to know how much improved it is with headers, but i'm just not thrilled with its performance when using exhaust manifolds...

I spoke to Wayne Guinn about this about 5 months ago, and he said that the LT1 was definately the way to go, but I wondered if anyone actually had any real "behind the wheel" experience with this cam..

according to the specs, it is 242-254 on a 116... so it shares the same exhaust lobe as the 30-30 but has a smaller intake lobe and is spread out to a 116...

thoughts?

i've read the 20% more torque and only a few hp off the top.. which is exactly what EA said, but i'd like to know from anyone who actually uses the cam?

Thanks

68Zproject

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Re: Anyone run the LT1 (178) cam in their DZ302???
« Reply #1 on: July 17, 2009, 10:29:51 PM »
It's up to you.  My car had a 69 DZ in it when I bought it and I got the CE engine with it too.  The 69 had the LT1 cam in it and I drove it for a while until it threw a rod.  Not too bad, it had some torque but didn't seem to have much pull at higher RPM. I then put a CC 282S in the CE engine and ran it.  Big difference.  The CE engine would smoke the DZ I had.  There may have been other factors involved as it wasn't a straight cam swap in the same engine and I'm no expert.  I can just tell you that the difference was night and day.  I have 3.73's and an M21.  My cam has plenty of torque to take off with, but really screams to 7k.  The LT1 engine was a dog compared to the CE one.  If you want to keep it as it was built I would get the 30-30.  You have plenty of gear with the 4.10's and M20 to take off with, but again it's what you want.  I do have headers though, but my exhaust is still stock from there and I would guess pretty restrictive.
68Z28

Stingr69

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Re: Anyone run the LT1 (178) cam in their DZ302???
« Reply #2 on: July 18, 2009, 09:45:57 PM »
I tried the 30-30 both with cast iron manifold and with 1-3/4" headers. The rest of the exhaust was factory style chambered exhaust so it was not the best. Not real thrilled with the results either way.

The car runs a LOT better for me now that I switched to the Crane F-278. The opening and closing points are almost identical to the LT-1 cam BUT the lift is higher so it is like an LT-1 grind with a little bit more. VERY nice improvement in the low end and it still pulls hard at higher RPM. I doubt it leaves much on the table. I have no plans to swap it again any time soon. I guess Crane is no longer in the business but maybe you could have one ground with the same specs?

I think John H. runs the LT-1 cam in his 302. Maybe he will have something to add.

-Mark.

JohnZ

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Re: Anyone run the LT1 (178) cam in their DZ302???
« Reply #3 on: July 19, 2009, 02:46:36 PM »
I think John H. runs the LT-1 cam in his 302. Maybe he will have something to add.

-Mark.

Nope - my '69Z has its original "30-30" cam; I've used the LT-1 cam in other project cars, however, and the improvement in low-end torque is noticeable.
'69 Z/28
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aaronz28

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Re: Anyone run the LT1 (178) cam in their DZ302???
« Reply #4 on: July 20, 2009, 01:09:49 AM »
yeah, I knew John had the 30-30 in his car, and i've run it at least a dozen times... the only time i used the LT1 was in a 327-365 and it didn't run very well at all, but that car had reduced compression and timing curve was way out of whack...

my Z has 11+compression,  wide ratio, and 4.10s... plus the motor is blueprinted and everything is spot on... before I rebuilt my Vette motor.. god only knows what it was up too LOL..

i currently have the 140 in the car an when it had headers on, it was very very nice to drive and enjoy, but i've put the stock manifolds and exhaust back on as I want to run the car in the Purestock drags.... while the LT1 cam isn't 100% technically stock for a 1969Z28, it isn't any bigger as the 140 is, so i'll be ok there.

i've gotten cam swaps down to an afternoon science in my car, so if i don't like the LT1 cam... 40 bucks worth of oil and gaskets, and about 4 hours, and i'll be back in business with the old 30-30 if the LT1 is disapointing.

i'm hoping the theory is true with regard to the LT1 cam being optimized for the Logtype manifolds on these cars... the 30-30 cam was designed for the L76 327 corvette engines which had 2.5 inch ramshorns... a far superior design.

So we'll see.

A

tryconcom

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Re: Anyone run the LT1 (178) cam in their DZ302???
« Reply #5 on: July 27, 2009, 12:52:36 AM »
arron; I am currently running an LT-1 cam in my fresh Dz 302 motor. I have 3:73s in the back and a wide box. The lt-1 cam has excellent low end in the 302 and pulls like gangbusters to 7000+ . I have had 30/30s in 302s in the past and they were dogs off the line till about 3-3500rpm. The lt-1 starts its  magic immediatly off idle(minimal clutch slipage) and is very flexable in traffic. IMO, it should be the definative installed cam in street driven (3:73 geared) cars.

aaronz28

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Re: Anyone run the LT1 (178) cam in their DZ302???
« Reply #6 on: July 27, 2009, 01:23:33 AM »
i actually got the car out on the street this week with the new LT1 cam... although it is advanced.
the C/L are 110/122 which make it 6degrees advanced, and i have it installed another 2 degrees.

i have to agree that it really makes up a world of difference down low, and I didn't notice any loss of top end compared to the 30-30.

Often, with a torquey cam, you loose the "seat of the pants" effect because the "bigger" cam has no bottom end, and when it finally comes on, it feels great.
this LT1 seems strong right out of the get, and you definately feel it "come on" but it still pulls like gangbusters till 7k.

can't wait to get it on the track to see how a bias-ply stock machine with manifolds, smog, and full exhaust run... i have the wide ratio and 4.10s. 
should be interesting

Aaron