#29547 - 12/27/07 07:49 PM
Custom Sissel 12 port head intake manifold 194-292 in progress
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Mean buzzen half dozen A.K.A. Hank
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Registered: 09/23/04
Posts: 4550
Loc: Ca
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#29551 - 01/19/08 02:23 PM
Re: Custom Sissel 12 port head intake manifold 194-292 in progress
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Randy S. Hager
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Registered: 10/31/06
Posts: 116
Loc: Venus, TX
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Hank: Is these for a Sissel head or did you take someone’s suggestion and make a 12 port out of an integral head 250? Someone started making NEW 3.0L heads for marine use but two welded together would be a little better breather than our siamese port heads. Yes they are made for a 4" bore but, since Douglas is drag racing a 250 with 4" bores well......
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#29553 - 01/23/08 02:17 PM
Re: Custom Sissel 12 port head intake manifold 194-292 in progress
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Randy S. Hager
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Registered: 10/31/06
Posts: 116
Loc: Venus, TX
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Hank: BUT he has 15:1 compression !!!! I'd say that would be a little stressfull on the thin bores. His seems to be holding up quite well. I'm looking into the 4" bore and having my crank stroked to 3.75". This would make a 283 cid engine. I only want to run 9:1 compression, not nearly as hard on those thin bores. I have a early 230 block which should have a lot thicker walls than a first year 250. (well, at least I hope so) Now if I can get the money saved up to get Edy's head and EFI intake up here to Texas..........
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#29557 - 02/13/08 09:41 PM
Re: Custom Sissel 12 port head intake manifold 194-292 in progress
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seiscanecos74
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Registered: 11/11/04
Posts: 176
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What about this Edy´s Head? Do you have some pics Randy?
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250 Chevy under tha hood, scratching tha foot
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#29558 - 02/13/08 09:51 PM
Re: Custom Sissel 12 port head intake manifold 194-292 in progress
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seiscanecos74
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Registered: 11/11/04
Posts: 176
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About the 4" pistons:
A engine builder & friend of mine said if you assemble it for street use lashing it 3 to 5 you won´t have any problem for years. But, otherwise, if you lash it 10 or 12 for track use, as it should be done, the block won´t survive much longer than 3 races.
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250 Chevy under tha hood, scratching tha foot
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#29562 - 02/18/08 12:04 PM
Re: Custom Sissel 12 port head intake manifold 194-292 in progress
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seiscanecos74
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Registered: 11/11/04
Posts: 176
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Yes, piston to wall clearence.
The machine shop usually lashes 0.003 or 0.004 for street use. Beyond that, for tracks, the lashing should be more due to the heating, piston material or whatever. If you lash a 4" piston in 0.012, the cylinder bores will be too big and then the wall to thin. Sometimes you can be lucky and nothing is going to happen, sometimes not.
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250 Chevy under tha hood, scratching tha foot
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#29563 - 02/18/08 10:15 PM
Re: Custom Sissel 12 port head intake manifold 194-292 in progress
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Randy S. Hager
Active BB Member
Registered: 10/31/06
Posts: 116
Loc: Venus, TX
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Good KB piston will run at .0015 to .002 so it would be easy to keep it tight. They do not expand very much and the high silcon will not let them scuff the cylinder walls. They can also be coated on the skirts to help out. 4" bore X 3.75" stroke = 283cid (rounded up)
seiscanecos74: You might know that Edy is using another head for his engine. He is not going to use the stock MEFI head and intake but it will take a lot of money to sent it here so I'll keep saving untill I have enough money to get it here. That set up will be a great conversation piece here in the states since we do not have anything like it.
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#42454 - 07/12/08 10:15 PM
Re: Custom Sissel 12 port head intake manifold 194-292 in progress
[Re: Randy S. Hager]
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ottoman
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Registered: 07/09/08
Posts: 6
Loc: WI
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Sorry for the late post but I am fairly new here and I am reading up on some of the older threads. Last time we bored one to 4 inch I sonic tested 4 or 5 blocks before I found one that was worth boring that far... and then I put in a 3/4 grout job. It worked well for the guy on a oval track for quit a few seasons. As a side note we now only leave a inch or so for water when we grout any type block... more strength and no cooling problems... street or track.
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#42465 - 07/13/08 11:04 PM
Re: Custom Sissel 12 port head intake manifold 194-292 in progress
[Re: Winter]
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ottoman
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Registered: 07/09/08
Posts: 6
Loc: WI
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Boy that was a few years ago... I think after boring the thinest parts were around .060. If I remember there was a lot of core shift in these blocks. I like to see at least .125 for HP street and more for race.
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