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292 chevy l6

66K views 22 replies 10 participants last post by  CNC-Dude 
#1 · (Edited)
292 chevy l6 advice

Does anyone know if there is a 292 stroker out there? or another straight 6 crank that would increase stock stroke?

I want to make this engine as strong as I can on a budget, but still have something I can depend on. Give me some suggestions on a cam, intake (4BBL or 3 carb), compression, Should I mill the head or buy pistons, ect.
I'm shooting for at least 300+ HP~ 1HP per CI
I want a good daily driver that can occasionally burn rubber, but I don't want to go the SB route just because everyone has one and I want to stand out a little. I've seen 292's that can easily do a 10 sec 1/4 mile... OH, this is replacing the stock 216 from a 1949 chevy 3/4 ton pickup
 
#2 · (Edited)
I was recently involved in a very thorough 292 dyno test over on Inliners. We tested (8)different cylinder head combos in various stages of porting and valve sizes. 300 HP will be very easy for you to achieve. We started with a bone stock 292 to establish a baseline, and even in bone stock trim(160 HP) yielded 300 ft. lbs of torque right from the 1800-2000 RPM on up in a straight line across the RPM range. All of these tests were done with a "pump gas" compression ratio of 8.8-1, and all parts were off the shelf components. The best HP combo was with a Clifford intake and a 4 bbl Holley carb, and all combos were still easily streetable, this combo also yielded 330 ft.lbs also. Stroking isn't necessary, and any rod other than a stock one is going to have to be custom($$$$), since it shares absolutely nothing in common with any other engine to do a swap with. Plus the bearing journal overlap on the crank is not very good on the stock crank anyway, and stroking it is only going to reduce it futher. I've built many of these engines for Comp Eliminator guys and have made over 600 HP with the 292 N/A, so you have plenty of power potential without having to stroke it. There is a guy on Inliners right now that has a Turbo 292 in his race truck that makes over 700 HP/800 ft lbs of torque, so there is plenty of ways to go to get power out of these engines.

The main key to power in these engines is in the head prep. You will have to consider large valves(1.94 intake) and removing the intake port bolt bosses and installing some bolt-in lumps. You can easily increase the flow from the stock port with 160-ish CFM with a 1.72 valve, to around 270 CFM with a 1.94 valve by doing this simple modification. Race heads can be made to flow 330+ CFM with even larger valves and more aggressive porting.
 
#3 ·
QParker said:
Does anyone know if there is a 292 stroker out there? or another straight 6 crank that would increase stock stroke?

I want to make this engine as strong as I can on a budget, but still have something I can depend on. Give me some suggestions on a cam, intake (4BBL or 3 carb), compression, Should I mill the head or buy pistons, ect.
I'm shooting for at least 300+ HP~ 1HP per CI
I want a good daily driver that can occasionally burn rubber, but I don't want to go the SB route just because everyone has one and I want to stand out a little. I've seen 292's that can easily do a 10 sec 1/4 mile... OH, this is the stock 216 from a 1949 chevy 3/4 ton pickup
Pick up a copy of Santucci's book "Chevrolet Inline Six-Cylinder Power Manual". This is a super good read for anybody looking to the Chevy inline 6 for power. Reviews at at Amazon, http://www.amazon.com/Chevrolet-Inline-Six-Cylinder-Power-Manual/dp/1931128154

As CNC said and as you'll read, the trick, or at least a big trick is in the head. Years ago we were happy with taking out the boss in the middle of the intake passage. As you'll see in the book, Kay Sissel came up with a gadget to change the contour of port floor to give a better entry on the short side radius to the valve.

Always think of the piston as part of the combustion chamber as with any engine build. Squish and quench are friends that let you run more compression per octane of fuel you're buying. While a lot of configuration details come into play making it hard if not impossible to predict the engine's ability to control detonation, the general rules are to keep the squish/quench deck with a steel rod in the range of .040 to .060 inch at TDC. If you need to increase volume above the piston use a piston that is dished only under the valve pocket, do not use pistons with circular dishes. If you can, use a flat top piston, if you must reduce chamber volume use a dome but as little of that as possible. If you use a domed piston, Singh slots cut into the piston rather than the head are useful for getting the flame front over the dome.

300 hundred horse from a 292 is easy to accomplish. Once the head and piston selection is set up, like any-other engine, it comes down to the cam, carbs and exhaust. balance and damping on the front of the crank are important to get an inline to live a long time at high power outputs. In line blocks are not as stiff as V design blocks, so keeping odd moments of inertia from developing on the crank to be transmitted thru the bearings into the block is an important undertaking for long term reliability. In lines tend to be sensitive to crank harmonics, so damping of vibrations is of significant importance.

Bogie
 
#6 ·
QParker said:
Can anyone recommend a mild cam for the 292?
How would the Clifford 264 cam be? Here's the specs on it:

*Our 264 cam is ground at .206 @ .050 with a big valve lift os .518. This is .112 higher valve lift than stock. Stock being .406 valve lift.
That Clifford cam is a good one, but you'll still be a long way away from your goal of 300 HP with it. You will also have to do some pretty extensive head work also to help get you to your goal HP as well. A Clifford intake will also be helpful, the Offy intake will fall short of getting you there also. A set of long tube headers with 1-5/8" primary tubes will help too.
 
#8 ·
How much power could I get from the 292 while still keeping it streetable with a mild cam and keeping the RPM's below 6000?
Everyone talks about HP, but if I have a 300-350HP 292 what would the torque be? That's what these engines are famous for, Right?! :thumbup:
 
#9 ·
One of the best combos we recently dynoed made 330 Ft Lbs of torque and was 300 HP. The RPM was well below 6000. The torque curve was almost a straight line from 2500 to 4200 or so. I looked at the Engle link, but didn't which grind you were meaning specifically. I'll look back at some of the dyno sheets and see what cam we used for the best peak HP and TQ #'s we got.
 
#17 ·
Oh, I thought you were referring to the street engine cylinder heads we were discussing for street useage. The best cylinder head used on the Comp Eliminator 292 race engine that made over 600 HP flowed as much as 349 CFM, and required many hours of brazing and port modifications to achieve this level of performance. Too bad they didn't last as long as it took to port them.:mad:
 
#20 ·
Does anyone know if there is a 292 stroker out there? or another straight 6 crank that would increase stock stroke?

I want to make this engine as strong as I can on a budget, but still have something I can depend on. Give me some suggestions on a cam, intake (4BBL or 3 carb), compression, Should I mill the head or buy pistons, ect.
I'm shooting for at least 300+ HP~ 1HP per CI
I want a good daily driver that can occasionally burn rubber, but I don't want to go the SB route just because everyone has one and I want to stand out a little. I've seen 292's that can easily do a 10 sec 1/4 mile... OH, this is replacing the stock 216 from a 1949 chevy 3/4 ton pickup
Go to Cotton Perry Ringold Ga website it will give you all the specs brand name of parts oversize and performance numbers he was a national record holder and he ran a 292 6 cyl cheyy and a 301 gmc inline 6 ,check it out
 

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#23 ·
It was a real awesome experience to have been able to be exposed to such racing icons as Jim and Cotton. It also was a daily surprise to see what well known racer would walk thru the door also and go to lunch with us just like one of the guys. Guys like Charlie Lee, Sonny Ray, David Rampy, Floyd Cheek, the late Bobby Hamilton, Larry Pritchett and of course all the Labbous'....I could write a book on all the racers that came in there on a regular basis. It sure was a sad time when Jim passed. His son Sandy and myself ran around, so I think your racing days were quite a bit before my time. Im sure I would recognize your name or face though. What memories....
 
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