330 to 350 overbore?

Jetstarjockey · 05-21-2006, 01:29 PM

Hi fellow Olds lovers,

I have a 64 330 HC 2bbl in a Jetstar 88 Holiday Coupe. Can this block handle a bore to accept the 350 pistons ? It has #1 heads and the shaft style rockers. Are these heads capable of making good power or should I store them and search for later small block heads ? Thanks guys!

Rob

Oldsguy · 05-22-2006, 03:15 PM

Rob, I could only say that the 350 gets it's displacement from more than the size of the piston, as you probably know. I will check my reference tonight to see how close the bore is in a 350 vs a 330. As another option you might check this spot out and ask "Blownolds". He is on the site in the link below as well as other Oldsmobile performance sites. He might be able to help you out too.

http://www.jalopyjournal.com/forum/s...highlight=olds

Jetstarjockey · 05-23-2006, 09:32 AM

Hi Dan, Thanks for the reply ! I have researched the Olds Small Block design and have discovered that all small blocks have a 3.385 stroke. I am lucky to have a forged crankshaft version in my 1964. The bore for the 330 is 3.938 and the 350 is 4.057 . The compression height on both pistons is 1.615 . I am hoping that the 330 block can recieve an overbore of at least .119 to facilitate the use of 350 Olds pistons rather than a .030 over . I found one source that claims the 330 will accept a .125 overbore with no problem...and I am hoping that someone here can confirm this . I suspect perhaps the 350 piston may be more common than the 330 and I would also benefit from the extra displacement and oversquare B/S ratio. Also, I have found plenty of info on the later SBO heads but nothing on the #1 heads that I have on my engine. I have ported several sbc heads with good results and would like to try the same with the Olds, but would like some opinions on the potential of the #1 head to post decent flow values after porting. I am hoping for about 240 cfm intake port to enable a 400hp build-up? I have just finished building a 1970 455 with ported E heads and will be using that engine in my Jetstar until I find a 71 Cutlass convertable for the Big Block. The 330 will be going back in the Jetstar eventually and there is no hurry to get it done at the moment. What I hope to achieve is a stock looking small block with 400+ horsepower in a large "slow appearing" classic ! I Think I have been bitten hard by the "Olds bug" and look forward to chatting with others here, and sharing my discoveries as they unfold !

Thanks very much for your help Dan, I am heading over to the site you mentioned for a look !

Oldsguy · 05-24-2006, 04:52 AM

Sounds like you have already been doing some homework! If you massage the intake ports of the heads, radius a few curves, lower the deck a little and un-shroud the valve guide area some it should definitely help. I am curious about your big block now, tell me more about the camshaft selection and how you found those E heads. The 455 I am going to use in my '48 has a pretty nice set of C heads. Anyway, keep us posted.

mickey3d · 05-24-2006, 02:12 PM

Hey JetstarJock,
Regarding all the questions that you posed,I have a phone number that
will get you directly in touch with Joe Mondello,of Mondello's Porting
Service.His legendary fame goes back to the dry lakes flathead days.
Joe knows more about Olds engines than anyone I know.He can tell you
how much boring ANY V8 Olds will stand.I think he is the most knowlegable
of anyone breathing on Olds performance. "There is non higher!!!"(sic B&B).
Best of all,he will always take time to talk to an Olds enthusiast!
I would give you his email address but he hates email!
His direct phone is : 1-888-666-3355 (don't pass it around to everyone).
Be sure to ask him about his porting school. The best I know of.
It's a one week course that includes hands on porting and using his flow
bench. It's pricy...$3000 which includes lodging and lunches for the week.
Not really bad to study at the feet of the master.
Have FuN1
MickeyD

05-21-2006, 01:29 PM	#1 (permalink)
Jetstarjockey Junior Member Join Date: May 2006 Posts: 4	330 to 350 overbore? Hi fellow Olds lovers, I have a 64 330 HC 2bbl in a Jetstar 88 Holiday Coupe. Can this block handle a bore to accept the 350 pistons ? It has #1 heads and the shaft style rockers. Are these heads capable of making good power or should I store them and search for later small block heads ? Thanks guys! Rob

05-22-2006, 03:15 PM	#2 (permalink)
Oldsguy Administrator Join Date: May 2004 Location: Lees Summit MO Posts: 2,859	Rob, I could only say that the 350 gets it's displacement from more than the size of the piston, as you probably know. I will check my reference tonight to see how close the bore is in a 350 vs a 330. As another option you might check this spot out and ask "Blownolds". He is on the site in the link below as well as other Oldsmobile performance sites. He might be able to help you out too. http://www.jalopyjournal.com/forum/s...highlight=olds __________________ Dan '46 2 door

05-24-2006, 04:52 AM	#4 (permalink)
Oldsguy Administrator Join Date: May 2004 Location: Lees Summit MO Posts: 2,859	Sounds like you have already been doing some homework! If you massage the intake ports of the heads, radius a few curves, lower the deck a little and un-shroud the valve guide area some it should definitely help. I am curious about your big block now, tell me more about the camshaft selection and how you found those E heads. The 455 I am going to use in my '48 has a pretty nice set of C heads. Anyway, keep us posted. __________________ Dan '46 2 door

05-24-2006, 02:12 PM	#5 (permalink)
mickey3d Member Join Date: Apr 2006 Location: North Texas Posts: 37	Olds Info Hey JetstarJock, Regarding all the questions that you posed,I have a phone number that will get you directly in touch with Joe Mondello,of Mondello's Porting Service.His legendary fame goes back to the dry lakes flathead days. Joe knows more about Olds engines than anyone I know.He can tell you how much boring ANY V8 Olds will stand.I think he is the most knowlegable of anyone breathing on Olds performance. "There is non higher!!!"(sic B&B). Best of all,he will always take time to talk to an Olds enthusiast! I would give you his email address but he hates email! His direct phone is : 1-888-666-3355 (don't pass it around to everyone). Be sure to ask him about his porting school. The best I know of. It's a one week course that includes hands on porting and using his flow bench. It's pricy...$3000 which includes lodging and lunches for the week. Not really bad to study at the feet of the master. Have FuN1 MickeyD

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05-23-2006, 09:32 AM	#3 (permalink)
Jetstarjockey Junior Member Join Date: May 2006 Posts: 4	Hi Dan, Thanks for the reply ! I have researched the Olds Small Block design and have discovered that all small blocks have a 3.385 stroke. I am lucky to have a forged crankshaft version in my 1964. The bore for the 330 is 3.938 and the 350 is 4.057 . The compression height on both pistons is 1.615 . I am hoping that the 330 block can recieve an overbore of at least .119 to facilitate the use of 350 Olds pistons rather than a .030 over . I found one source that claims the 330 will accept a .125 overbore with no problem...and I am hoping that someone here can confirm this . I suspect perhaps the 350 piston may be more common than the 330 and I would also benefit from the extra displacement and oversquare B/S ratio. Also, I have found plenty of info on the later SBO heads but nothing on the #1 heads that I have on my engine. I have ported several sbc heads with good results and would like to try the same with the Olds, but would like some opinions on the potential of the #1 head to post decent flow values after porting. I am hoping for about 240 cfm intake port to enable a 400hp build-up? I have just finished building a 1970 455 with ported E heads and will be using that engine in my Jetstar until I find a 71 Cutlass convertable for the Big Block. The 330 will be going back in the Jetstar eventually and there is no hurry to get it done at the moment. What I hope to achieve is a stock looking small block with 400+ horsepower in a large "slow appearing" classic ! I Think I have been bitten hard by the "Olds bug" and look forward to chatting with others here, and sharing my discoveries as they unfold ! Thanks very much for your help Dan, I am heading over to the site you mentioned for a look !