I just put my 1970 350 LT1 motor on the dyno.
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1970 350 LT1 Dyno Test
69z28freak
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Hi Tim you are correct. We used a 4 bolt main truck block with original bore. Not sure what happened to the original block, but my builder said we would be better off with this one. I left the original stamp on the block so that everything would be up front. I am not going to restamp it or try to pass it off as a DZ block to an LT1 block. However you would be surprised at how many people suggest I should have done that. If this build does not snap my neck, I will look at another option next winter. So far it has been a great learning experience. I am looking forward to applying my knowledge in the future.Mike,
Great result, this build has a good vibe
From the block pad stamp, looks like a 1975 truck application :thumbsup:
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What paint did you use on your motor. It looks great. Also what harmonic balancer and what water pump did you use.
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How much for the trans?
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Paint is vht chevy orange,In a rattle can. Water pump came from napa. The harmonic balancer was from summit.It wasn't the best ,but was better than stock. I can't remember the brand name,but I think it had summits name on the box. I think it was rated for 500hp.
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Car looks awesome.
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It looks like we are on the same program. I have been working on mine for almost 3 years now. Hopefully we both get done sooner than later. I hope to have mine on the road this summer.
My shortblock is a 70 Z28 LT-1 clone too
Added Crane HR 119841 cam .539/.558 lift 234/242 Dur, 112 LC
Canfield 197cc heads 23-500-65 Untouched as the as cast ports are gorgeous!!
Works well too.
I have a 69 Z28 intake and matching 780 carb if I wanted to use them.
Added Crane HR 119841 cam .539/.558 lift 234/242 Dur, 112 LC
Canfield 197cc heads 23-500-65 Untouched as the as cast ports are gorgeous!!
Works well too.
I have a 69 Z28 intake and matching 780 carb if I wanted to use them.
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Hey Tom that sounds great. Can you post any pics of your car and motor?
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I upgraded to 1.6 roller rockers and got a bit more power. Here are the latest results. Motor revs a bit higher and sounds a bit tougher. Acceleration is also smoother and more responsive. It was a cheap change, but a valuable one IMO. MAde a small change in the jetting as well. Running a 71 in the front and 72 in the back. Seems to like motor likes that combo the best. Plugs looked great, temp and oil pressure right on the money. Glad I went the dyno route to dial it in. Well worth the money spent, for peace of mind and getting it right for first fire in the car.
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Thats exactly the same power as the last one I did. My customer actually had me use the same 492 angle plug heads also, you could overlay the power graphs.I just put my 1970 350 LT1 motor on the dyno.
1970 LT1 350 Dyno Part 15 - YouTube
1970 LT1 350 Dyno Part 16 - YouTube
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Good question Gary. What cam is the L78 cam?
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What year was that the stock LT1 cam. I thought the 30/30 was the stock cam in the 1969 302 & 1970 LT1, and the upgrade was the 140 cam?
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The "178" was the cam the 70 lt-1 was released with in the 70 z/28, and 70 lt-1 corvette. It has less intake duration( 242 vs 254) on the intake, and 2 degree wider lobe seperation. This was so the motor could be used behind both an automatic, and 4 speed. Original tests on the 70 lt-1 at G.M. engineering used the 30-30 cam.
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Thanks Harry, that is good info. My motor seems to like the 30/30 in the current configuration. I am still curious however how the motor would perform with the 140 cam.
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