Questions about 69 rocket

69rocket · 12-18-2006, 10:26 PM

Hey Guys I have a 1969 350 rocket small block (2barrel) I've heard acouple different things about this motor.. i was wondering if you guys could clear afew things up ive heard the rocket 350 2 barrels had 290 HP and 10:25compression ratio

is this all true ??

Oldsguy · 12-19-2006, 04:39 AM

Good to see you here, welcome to our site! The rocket is a moniker for the Olds engine that has been in use for maybe 50 years at least. I think they started using it in the early 50's maybe as early as '49 when the first V8 came out. It just refers to an Oldsmobile V8. Your 350 with the 2bbl probably isn't 10.25:1 compression ratio because with the 2bbl carburetor it was the base engine and didn't really need that super high compression. I would guess 9.5:1 cr. It is a good engine and many Olds enthusiasts prefer the SBO (small block Olds) to the BBO (big block Olds) for it's higher reving capabilities and potential. Just like any other flavor, you find those that like the SBO, those that like the BBO and even those that specify a particular displacement like the 350. To each their own, at least we all love our Oldsmobiles

. Oh, by the way I think 290 hp is just about right, I haven't checked it but it sounds close. I bet there will be others to reply on this thread with more specific data.

69oldsguy · 12-19-2006, 08:44 AM

The '69 350-2 was a 250hp motor with a CR of 9:1. If this is what you have. Check all of your numbers on the block and heads to be sure of what year engine you have. If it is a '69 motor the good news is that the heads are the same for both the 9:1 and the 10.25:1. The difference was piston only. This applies to non W-31 motors. You could have a 10.25:1 motor with a 2 BBL carb on it. A lot of people chucked the Q-jet in favor of the 2GC's thinking they would get better mileage.

Either way, it is very easy to bring the 250hp motor alive. It just depends on what you want.

69rocket · 12-19-2006, 10:35 AM

I'll have to have a closer look for numbers thanks for the responses guys, I know we took the motor out of a 1969 4 door cutlass that an old granny had sittin for awhile the motor doesnt even have 50,000k on it which is pretty good, me and my pops took it out like 3-4 years ago before i really knew much about cars.. i know it came iwth a 2 barrel, we cleaned it all up put a Edlebrock RPM highrise intake and a comp cam, rebuild a Q-jet 4 barrel pretty sure its a 850cfm, nice 4 core rad, .. so where abouts are these #'s i should be lookin for again? on the heads?

12-18-2006, 10:26 PM	#1 (permalink)
69rocket Junior Member Join Date: Oct 2006 Posts: 3	Questions about 69 rocket Hey Guys I have a 1969 350 rocket small block (2barrel) I've heard acouple different things about this motor.. i was wondering if you guys could clear afew things up ive heard the rocket 350 2 barrels had 290 HP and 10:25compression ratio is this all true ??

12-19-2006, 04:39 AM	#2 (permalink)
Oldsguy Administrator Join Date: May 2004 Location: Lees Summit MO Posts: 2,859	Good to see you here, welcome to our site! The rocket is a moniker for the Olds engine that has been in use for maybe 50 years at least. I think they started using it in the early 50's maybe as early as '49 when the first V8 came out. It just refers to an Oldsmobile V8. Your 350 with the 2bbl probably isn't 10.25:1 compression ratio because with the 2bbl carburetor it was the base engine and didn't really need that super high compression. I would guess 9.5:1 cr. It is a good engine and many Olds enthusiasts prefer the SBO (small block Olds) to the BBO (big block Olds) for it's higher reving capabilities and potential. Just like any other flavor, you find those that like the SBO, those that like the BBO and even those that specify a particular displacement like the 350. To each their own, at least we all love our Oldsmobiles . Oh, by the way I think 290 hp is just about right, I haven't checked it but it sounds close. I bet there will be others to reply on this thread with more specific data. __________________ Dan '46 2 door

12-19-2006, 08:44 AM	#3 (permalink)
69oldsguy Junior Member Join Date: Dec 2006 Location: Wyoming Posts: 23	The '69 350-2 was a 250hp motor with a CR of 9:1. If this is what you have. Check all of your numbers on the block and heads to be sure of what year engine you have. If it is a '69 motor the good news is that the heads are the same for both the 9:1 and the 10.25:1. The difference was piston only. This applies to non W-31 motors. You could have a 10.25:1 motor with a 2 BBL carb on it. A lot of people chucked the Q-jet in favor of the 2GC's thinking they would get better mileage. Either way, it is very easy to bring the 250hp motor alive. It just depends on what you want. __________________ 69 Cutlass S 350-2 TH350 Buckets - Console 52,000 original mi.

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12-19-2006, 10:35 AM	#4 (permalink)
69rocket Junior Member Join Date: Oct 2006 Posts: 3	I'll have to have a closer look for numbers thanks for the responses guys, I know we took the motor out of a 1969 4 door cutlass that an old granny had sittin for awhile the motor doesnt even have 50,000k on it which is pretty good, me and my pops took it out like 3-4 years ago before i really knew much about cars.. i know it came iwth a 2 barrel, we cleaned it all up put a Edlebrock RPM highrise intake and a comp cam, rebuild a Q-jet 4 barrel pretty sure its a 850cfm, nice 4 core rad, .. so where abouts are these #'s i should be lookin for again? on the heads?