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Discussion Starter #1 (Edited)
Is it true that you can bore the 292 block .100 over and use 327ci pistons? I heard that somewhere. Also, what carburation would be best? Offenhauser makes several intakes for this engine for several different carburations. I´m looking for best bang-for-buck ´cuz I´m operating on a rather slim budget.
 

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I wouldn't be boring that block .100" over. About the only thing you can do for that engine is build it for torque, put a header on it and maybe a 4bbl intake on it. Head work (porting) would help a little, and milling the head would help compression. I don't think any pistons are available besides stock types.

tom
 

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Discussion Starter #5
why would you not recommend boring the block .100 over? I´m not trying to be a smart-a**, I´m honestly curious. If it could work I think it would be a great inexpensive upgrade. It would be easier to find pistons for a 327 than pistons for a 292. I remember reading once about a 292 that was bored over so and so amount and used pistons originally intended for an engine running on natural gas.
 

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are you sure it´s not inliner.org? I put in inliners.com and microsoft suggested inliners.org which looks like the same thing. Thanks. :thumbup:
 

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phelan said:
why would you not recommend boring the block .100 over? I´m not trying to be a smart-a**, I´m honestly curious. If it could work I think it would be a great inexpensive upgrade. It would be easier to find pistons for a 327 than pistons for a 292. I remember reading once about a 292 that was bored over so and so amount and used pistons originally intended for an engine running on natural gas.
A 292 is a 3.875 bore. boring .100 woulld make it 3.975. A 327 std bore is 4.00. If your asking if you can bore a 292 .125 over to make it a 4 inch bore, the answer is yes you can. Now if you want to know if you can use a 327 piston in a 292 bore .125 over, the answer is no. A 292 has a stroke of 4.120, a 327 has a stroke of 3.250, or the same stroke as a 307 and in the L-6 line, a 194 and a 230. You can use those piston interchangable with the correct bore. A 292 is all by it's self.
 

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I've built and raced many 292's at the 600HP level, and I can tell you that the cylinders are way too thin at the 4.000" bore size. A .060 over is about as far as you want to try to bore one, and you can still make plenty of power with that. The best method for increasing the HP is by having the head "lump" ported, and bumping the compression a little. You can have a pretty conservative 350-400 HP street engine, but it is a little more expensive than trying to get the same out of a V8 though. As already has been stated, the 292 is in a field all its own as far a piston swap goes, and any performance piston will likely have to be custom, but they are available from Ross or JE and most other premium brands.
 

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292 performance

OK guys im new here so go easy on me if im correct your talking about 292 performance Ive built a few L6s in my time and to be honest i love them i guess because im a little different if you want to build a bad *** 292 this is the recipe first find a good 250 block some 250 blocks can go 4.000 but very few and when they do there not street worthy the best way to achieve a 4.000 bore is to cut the block and have it sleeved for the 4 inch bore but if your only going for 292ci your not going have to do this next use a 292 crank small block chevy 5.7 rods and if you stay with the 3.875 bore use 307 flat top pistons if going with 4inch bore use 327 pistons now the top end use a 194 head witch-has a 60cc chamber cut them for small block chevy 1.94 intake and 1.5 exhaust if your going with a high lift cam use .100 longer valves put lump ports in your head now you've got a good breathing high compression 292 3.875 or 311 4.000
 

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gas_guzzler said:
Welcome new people :)

What do you mean by lump ports dixiegasser and CNC dude?
Gas_guzzler, the lumps are a technique developed by Kay Sissell which he used to form a ramp or lump in the intake ports to create a short side radius. In the inline heads such as the siamese Chevy sixes, the port floor is almost flat, and has virtually no short side radius at all. Sissell's method was to braze the lumps in the head using brass rods to build up and form it in the port, along with an oven and a lot of time. Today, a bolt-in lump is available that does not require the time exhaustive methods used by Sissell, and is much less expensive to do. A group of us over on Inliners have just done some extensive dyno testing with a 292 and many different levels of lump heads. The results generated so much response, that we are going to be doing a completely new engine and many more different components in February, so check it out. We tested (8) different cylinder heads of various valve sizes and chamber sizes. I can tell you that the 194 casting cylinder head is probably not the best head to use. Even though you do gain a slight amount of compression, the chamber shrouding with the 1.94" valves hurts the power more than you gain with the compression, and we consistently saw a 10 HP and torque lose with every combo we tested with it, compared to the large chamber head with the same size valve. Even with unshrouding around the intake valve, the 194 head casting is one of those "urban legends" that has been accepted for a long time, but since no one has ever done any significant testing with these engines, it has just always been assumed to be true. So much info has been gathered and learned, that a new series of books and performance manuals is going to be written about these engines, as well as several magazine articles. We have some really good engine recipe combos that im sure you guys down under would really like, so watch for the new tests coming up on www.inliners.org


Also, using a SBC rod in these engines creates a huge internal oil leak, since the SBC rod is .100 narrower than the original 6 cylinder rod, so you are setting yourself up for a big problem. A better choice is a Scat H-beam rod, that is application specific for these Chevy 6 engines, and provides the correct rod side clearances, or you can go with custom rods.

To give you an example of the type of gains you can experience with the lump ports, a stock siamese head with the stock intake port and a 1.72" intake valve will flow around 160 CFM, and with the bolt bosses removed and the bolt-in lump installed using a 1.94" valve, you will consistently see 240-ish CFM at .500 lift. Thats an 80 CFM gain for doing very little work. Many of Sissell's top shelf brazed heads will flow well over 300 CFM. There aren't many stock production heads that you will ever get that type of gain out of....
 

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if thurs a will thurs a way

i have to retract on my previous post one part by looking in my notes i made a booboo using the 292 crank with 5.7 rod in a 250 block you have to use a custom piston or should be the same as a 383 with 6.00 rod or 335 with 6.000 rod a compression height or rist pin height around 1.125 :confused: and cnc dude thanks for the info on the rods
 

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phelan said:
Is it true that you can bore the 292 block .100 over and use 327ci pistons? I heard that somewhere. Also, what carburation would be best? Offenhauser makes several intakes for this engine for several different carburations. I?m looking for best bang-for-buck ?cuz I?m operating on a rather slim budget.
Get a copy of this book. It'll answer a lot of your questions and do much to keep your project on track and budget.

http://www.amazon.com/Chevrolet-Inline-Six-Cylinder-Power-Manual/dp/1931128154

Bogie
 

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dixiegasser said:
i have to retract on my previous post one part by looking in my notes i made a booboo using the 292 crank with 5.7 rod in a 250 block you have to use a custom piston or should be the same as a 383 with 6.00 rod or 335 with 6.000 rod a compression height or rist pin height around 1.125 :confused: and cnc dude thanks for the info on the rods
No problem dixiegasser. I think the main thing is that these engines are often overlooked for the potential they really have.
 

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Thanks for the info CNC-dude. That's some really impressive gains! I'll definately check that site out

Over here 6 cylinder chevs aren't very common. a 202/3.3 holden (Australia gm) would much more likely be used. After market performance heads are available for these motors. (I'm unsure what they flow though)
 

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Gas_guzzler, back in the day, Duggan down there in Australia was the man for Chevy 6 stuff. He made the patterns for an aluminum 12 port head for the Chevy 6's, that were later purchased by Sissell.
 
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