1970 LT1 [Archive] - Team Camaro Tech

: 1970 LT1


MJM
Mar 1st, 05, 05:12 AM
Does anyone have the specs such as cam type, compression, cyl heads etc. for the 1970 1/2 LT1 Z-28 Camaro engine? I have seen this rated at 350hp, 360Hp, and 370Hp. Which is right? Thanks.

pdq67
Mar 1st, 05, 08:22 AM
360hp Camaro and 370hp 'Vette/350 motors,

Good old -178 solid cam, 11 to 1 CR. (And the mule Motor got the 370hp rating from a -346, 30-30 Duntov Fuelie cam)..

There is a 350 hp/350 motor too but I think it uses the -969 hy-cam if not mistaken

And the later, lower Cr. versions that used the -178 solid cam were 330hp??

Hope I have this right b/c I'm more a First Gen. motors guy.....

pdq67

f370vette
Mar 1st, 05, 12:01 PM
Vette and Z motors were identical. Vette was rated at 370 horse because of a better exhaust system. Compression was 11/1. If I remember correctly, the 350 horse was a hydraulic cam with a 750 carb, while the 360 and 370 horse versions had 780 cfm carbs. Real stormers I owned a 70-1/2 Z.

MJM
Mar 1st, 05, 01:34 PM
Is the 370 HP the same cam as the 302 or modified for the 350? Was going to build a 383 for my 69 but I have the chance to buy at a really good price a HP 1970 350 from a z I figure if I bring it up to the 370 HP specs It could be a lot of fun to drive and have that nice solid lifter sound and probably save myself a fair chunk of change.

f370vette
Mar 1st, 05, 03:36 PM
I haven't been able to find my old books with cam specs. If I find them I'll list the specs. Regardless I wouldn't use an old design in a 383. I'd call Crane or Comp and give the details of the car and how it's to be driven and let them make a recommendation. Both have always been right on with their recommendations. Even special grinds are reasonable with CNC cam grinders.

zdld17
Mar 1st, 05, 04:12 PM
Direct from the GM HP parts books,,, 70 Lt 350 cam specs were I .458/ E .485 lift at Zero lash. Valve timing:Intake
Open BTC 42 deg@ .40
Clos ABC 94 deg@ .20
Duration 317 deg
Lash .24
Exhaust:
OpenBBC 112 deg @ .50
Closing 53 deg @ .23
Duration 346 deg @ .46
Lash .30
GM part # 3972178.
This was almost same cam as earlier Z28 cam with less duration and split pattern
Hope this helps

pdq67
Mar 1st, 05, 04:20 PM
Like I said, the 370hp/350 motor dyno number came from GM's Mule motor that had the 290hp/302 and 365hp/375hp/327 solid cam in it!

All production motors came with the -178 solid cam b/c they could run it with A/C AND an automatic whereas the old 30-30 solid cam just didn't like A/C and automatics!!

I'd go with a good old CC 282S or even a 294S solid in a strong 383 as long as it is right at 10 to 1 CR, imho...

pdq67

Small block solid cam spec's:

1. –097, little Duntov solid, (287/287 per GM and 272/272 per Pat K.)/228/231, .395”/.383” net, .401”/.383”net, 110.5/108. A GREAT LITTLE CAM, IMHO!!! I ran it in my junk 301 for a couple of years..

2. –178, 330/350 solid, 242/254, .459”/.439net,.485”/.455”net, 116/110.

3. –346 big Duntov or 30-30 solid, (346 per GM, 314 per WBR and 304 per Pat K.)/254/254, .486”/.456”net, .486”/.456”net, 114/112. The cam that gives the 302 it's distinctive sound!!!

4. –140, Z-28 Off Road solid, 257/269, .493”/.469”net, .512”/.486”net, 112/108. More "balls-out"!!

Small block hy-cam spec's:

1. –151, 350/327 hydraulic, 222/222, .447”/.447”, 114/110. Runs great in an L-48 295hp/350 motor!! I ran one for several years in my stock, 295hp/350 motor..

2. –962, 350/350 hydraulic, .450”/.460”, 115/114.

rszmjt
Mar 1st, 05, 04:26 PM
Corvette 370 HP also had TI ignition, while the camaro used points. I had heard that this made up the extra 10 hp rating.

Just my .25 worth.

zdld17
Mar 1st, 05, 04:32 PM
pdq67,,you forgot one ,, 3965754
.512 intake
.536 exh
324/334.

even more balls!
And lets not forget the one that started it all
55/56 "077" 265 ci notch cam

MJM
Mar 1st, 05, 07:39 PM
If I go with the 383 modern roller cam. Great input on a cam for the 70 1/2 Z 350, as much as I like the old school solid cam I also like the 435HP-450 ft lbs of torque from a mild 383. The 350 hi-pro engine (CTB) is a lot cheaper..what a decission!!! :confused:

pdq67
Mar 2nd, 05, 02:52 PM
Right you are there!! Money is one reason why I am staying "Old-School" in my "Old-Age" sorta deal.

Seems that the high-zoot, modern stuff just costs a lot more for not all that much more bang for my hard-earned buck...

But, again, I'm a tight-a--, --er, eh, "frugal" is all...

But I do know that a good street solid roller will make alotta POWER!!

pdq67

MJM
Mar 2nd, 05, 03:22 PM
RIGHT-ON graemlins/beers.gif