Will it run on pump gas?
Thread Starter
Drifting
Joined: Apr 2002
Posts: 1,716
Likes: 4
From: New Baden Illinois
Will it run on pump gas?
I am exploring the opportunity to install an engine from of a 1970 Camaro SS. It is the 350 with 300hp. Apparently this engine was rated at 10.25:1 CR. This was obviously before the transition to unleaded fuel. Will this engine be OK to run on today's pump gas, or do some mods have to be done to accomodate it?
I really don't want to have to buy a bunch of extra parts to convert it. The engine only has approx. 44,xxx miles on it, so I would like to just freshen it up.
Thanks everyone.
I really don't want to have to buy a bunch of extra parts to convert it. The engine only has approx. 44,xxx miles on it, so I would like to just freshen it up.
Thanks everyone.
Le Mans Master
Joined: Jan 2006
Posts: 8,319
Likes: 7
From: Wilmington DE, Drive it like you stole it, 68 327 4 speed coupe
Originally Posted by dgruenke
I am exploring the opportunity to install an engine from of a 1970 Camaro SS. It is the 350 with 300hp. Apparently this engine was rated at 10.25:1 CR. This was obviously before the transition to unleaded fuel. Will this engine be OK to run on today's pump gas, or do some mods have to be done to accomodate it?
I really don't want to have to buy a bunch of extra parts to convert it. The engine only has approx. 44,xxx miles on it, so I would like to just freshen it up.
Thanks everyone.
I really don't want to have to buy a bunch of extra parts to convert it. The engine only has approx. 44,xxx miles on it, so I would like to just freshen it up.
Thanks everyone.
Thread Starter
Drifting
Joined: Apr 2002
Posts: 1,716
Likes: 4
From: New Baden Illinois
How does the lead substitute work? Do you have to add a bottle at every fill-up, or do you just add it every so often?
Also, wouldn't the lead substitute compensate for the higher CR. If so, would it be able to run on the pump gas without the lead?
Also, wouldn't the lead substitute compensate for the higher CR. If so, would it be able to run on the pump gas without the lead?
Safety Car
Joined: May 2003
Posts: 3,814
Likes: 105
From: Dearborn Heights Michigan
I run Sunoco 94 in my 70 L46 (CR= 11:1) with no problems. There was a thread earlier about lead substitute. An extensive study by, I believe, Citicorp found lead substitute is not needed in pre unleaded engines and no harm will result from using unleaded. Do a search to find the thread. I have stopped using the sub in my 70 and 55 pickup as well.
Fred
Fred
Le Mans Master
Joined: Jan 2006
Posts: 8,319
Likes: 7
From: Wilmington DE, Drive it like you stole it, 68 327 4 speed coupe
Originally Posted by dgruenke
How does the lead substitute work? Do you have to add a bottle at every fill-up, or do you just add it every so often?
Also, wouldn't the lead substitute compensate for the higher CR. If so, would it be able to run on the pump gas without the lead?
Also, wouldn't the lead substitute compensate for the higher CR. If so, would it be able to run on the pump gas without the lead?
many varying opinions here, but your car will run on pump gas fine,
while some will say it makes no difference, my personal experiance with lead substitue it that my car runs better with it than without it, you will hav to see for your self?
Melting Slicks
Joined: Feb 2006
Posts: 3,428
Likes: 5
From: Japan
Just as a point of contention, when I first bought my 350/300 '70 back in 1997 (10.25:1 CR just like yours with 46k miles on it) it would ping on 92 octane pump gas unless I added some decent octane booster to it. There may have been some ignition timing issues there too, but with the additive it would run quite well. I have since bored it .030" and fitted 9:1 pistons; it now runs quite happily on 87 swill (but it's not gonna win any races...)
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Melting Slicks
Joined: Jun 2004
Posts: 2,077
Likes: 0
From: westmoreland N.H.
what i do for my 70 l-46 with 11.0-1 comp ratio is to get 100 low lead at my local airport, and add one gallon per fillup of 93 octain. it gives you a boost in octain (about 95) ,and give you the lead your engine needs. also a bit less expensive than lead substitute...
Safety Car
Joined: Aug 2000
Posts: 3,711
Likes: 43
From: San Antonio TX
You shouldn't need any tricks to get it to run on pump premium. That 10.25:1 compression ratio is the blueprint ratio and your ratio is likely under 10:1. The built ratios are closer to a half a point lower. If you do have issues, then you need to work on the tuneup and make sure the combustion chamber is relatively clean. You may find that by working the ignition total and centrifugal advance rate that you could probably make it run okay on mid-grade.