SoCal Jet Boats

Tech Talk => Engine Mechanical / Electrical => Topic started by: coors909 on November 08, 2015, 08:56:28 PM

Title: BBC heads
Post by: coors909 on November 08, 2015, 08:56:28 PM
I wanted to know which number tells me what heads I have?  These are the numbers I found gm11T or A2170


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Title: Re: BBC heads
Post by: GT Jets on November 08, 2015, 10:42:49 PM
I wanted to know which number tells me what heads I have?  These are the numbers I found gm11T or A2170


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Probably foundry and a date.

The number you want to use for identification is the casting number. Typically cast into the head under the valve cover.

GT
Title: Re: BBC heads
Post by: coors909 on November 09, 2015, 06:38:32 AM

Probably foundry and a date.

The number you want to use for identification is the casting number. Typically cast into the head under the valve cover.

GT

Ok. Those were the two numbers on the head under the valve cover. Maybe there is another one under there somewhere


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Title: Re: BBC heads
Post by: GT Jets on November 09, 2015, 07:03:52 AM
Are they GM heads?

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Title: Re: BBC heads
Post by: crewchief22 on November 09, 2015, 06:32:38 PM
Going to be a 6 or 7 digit number.  Two very common cylinder heads found on Jet boats are 353049 oval port and 6272990 rectangle port.
Title: Re: BBC heads
Post by: coors909 on November 09, 2015, 07:00:00 PM
3964290 is what I have


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Title: Re: BBC heads
Post by: GT Jets on November 09, 2015, 07:25:18 PM
3964290 is what I have


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3964290....69-70...oval..CLOSED..396, 402, 427, 454, 101cc chamber
Large or small hex spark plugs used.
Title: Re: BBC heads
Post by: brian777 on November 09, 2015, 08:47:50 PM
What are 6272292?


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Title: Re: BBC heads
Post by: GT Jets on November 09, 2015, 09:10:07 PM
What are 6272292?


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Lol


6272292....70-78...oval...OPEN...402, 454
Title: Re: BBC heads
Post by: brian777 on November 09, 2015, 09:18:33 PM

Lol


6272292....70-78...oval...OPEN...402, 454
thanks gt so are these worthless like the rest of my motor?😭


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Title: Re: BBC heads
Post by: GT Jets on November 09, 2015, 09:50:36 PM
thanks gt so are these worthless like the rest of my motor?😭


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Not necessarily worthless.

Good heads for low rpm range horsepower. Would respond well to a good RV grind cam if your compression ratio was high enough (thinking 9.5:1).

For the demands of a jet pump, probably not the right head. Work good in an I/O.

GT
Title: Re: BBC heads
Post by: brian777 on November 09, 2015, 09:52:32 PM

Not necessarily worthless.

Good heads for low rpm range horsepower. Would respond well to a good RV grind cam if your compression ratio was high enough (thinking 9.5:1).

For the demands of a jet pump, probably not the right head. Work good in an I/O.

GT
ok I'll toss them in the scrap pile too!


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Title: Re: BBC heads
Post by: 69kona on November 10, 2015, 06:58:14 AM
I'll take them ..lol


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Title: Re: BBC heads
Post by: Six-Oh-Nine on November 10, 2015, 09:17:40 AM
ok I'll toss them in the scrap pile too!


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Well since you're gonna scrap them out because they are "worthless"... I'll take your junk and make it a little treasure for someone else... Thanks for the donation! Where can I pick them up? :thumbup: :thumbup:
Title: Re: BBC heads
Post by: 69kona on November 10, 2015, 12:30:07 PM

Well since you're gonna scrap them out because they are "worthless"... I'll take your junk and make it a little treasure for someone else... Thanks for the donation! Where can I pick them up? :thumbup: :thumbup:

That's what I'm saying I take them "worthless " heads lol


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Title: Re: BBC heads
Post by: Six-Oh-Nine on November 10, 2015, 05:12:35 PM


That's what I'm saying I take them "worthless " heads lol


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I've made some decent power on jet boat motors with those "worthless" heads... So I'll take all of them out of everyone's trash barrel! Lol!


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Title: Re: BBC heads
Post by: rush1 on November 10, 2015, 06:59:49 PM
I'm looking for a set of those heads
Title: Re: BBC heads
Post by: brian777 on November 10, 2015, 07:26:43 PM
Well these r pretty good heads if matched with the right Pistons to create higher compression they cc at 110 just not big enough for the power I want might be up for sale soon


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Title: Re: BBC heads
Post by: Towtruk69 on November 10, 2015, 07:27:20 PM
I have a pair of 049 heads that need to be rebuilt if anyone is interested. $50
Title: Re: BBC heads
Post by: coors909 on November 10, 2015, 09:21:44 PM

I have a pair of 049 heads that need to be rebuilt if anyone is interested. $50

Where are you located?


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Title: Re: BBC heads
Post by: Towtruk69 on November 10, 2015, 09:32:27 PM
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