So I just got a chevy 292 from a mate for free from an old grain truck (im in australia) and its a mexican one? I want to build an insane race engine for my car to take to the drags everynow and then. My ideas are NA at the moment and specs are : Heavily ported head with SBC valves, Lump port, BBC valve gear Block bored .030 or .040 Block o-ringed Either TWR pistons or custom JE pistons Stock rods with larger bolts, shotpeened etc etc. Lightened crank, balanced Lightened flywheel ARP bolts/studs alround MSD igniton Clifford 4 barrel intake or Custom made aluminium 3X4 (3X390/465)? Custom headers Clifford drag cam: Mechanical- .635/.647 lift ADV. duration- 310/320 duration at .050- 270/276 Hopefully run 11:1+ compression Any other options or opinions are welcome Thanks
I do not think that lightening the crank & flywheel is the way to go on a drag motor, the heavier assembly is good for launching if you are leaving at an RPM in the 1,500 and up range. Have the block align honed to the factory minimum bore size and have your crank ground to the ID of the bearing diameter- shoot for .0025-.0027 clearance. You may have to go with aftermarket connecting rods since the standard rod length is 5.7 (the same as a (194/230/250) but the additional block height was made up by a much higher piston with a 1.918 compression distance versus the 1.640 on the 250. There is always a chance you could rework a set of rods from another engine to get make up the +.338 difference but that takes a bit of research. If you shoot for .0015 to .0017 rod bearing clearance it will be OK if a different rod is a bit narrower than the standard rod. Volvo proved that rod side clearance can be enormous with no ill effect on oil pressure in their B230 engined that had the rod located by the pin bore and a ton of space between the rod and the rod throw fillet. That engine will have to have a good quality aftermarket balancer- we used 350 Chevy dampers and machined the crank collar down to get the damper close to the block like the standard balancer is. Since it is a drag motor and rotating mass can be an advantage when leaving and you have a real long stroke my recommendation would be the 8" balancer. Cast cranks by nature are very rigid cranks with little tolerance for flex like a forged crankshaft, that is why if a cast crank is not stable they will break. You will be the loser in a spitting contest with a snake if you run that engine above 5,500 RPM. This block demands torque plate honing with the main caps installed. When we would install the torque plate and main caps after boring the block the cylinders would go .002 out of round from the top to the bottom of the bores. I do not think o'rings on the block are needed but if you can find a 194 cylinder head they have a smaller chamber and you can get a more compression. We ran .620 lift and 245 degrees of duration at .050 on a short oval track engine and the pistons did not need any valve notches. The heads can be milled .060 with room left for clean up mills and have the deck milled also. Shoot for a 0 deck or bring the piston above the deck to tighten up the squench but if you end up with aluminum rods have the rod supplier tell you how much length the will pick up.
what are you planning to put this in? Normally you build a motor for a class or type of car your planning to run because everything you do to the motor revolves around that.
great info^ thanks mate. The motor is just a practice build for a GMC 302 when im older, hopefully i can put it into my torana (2100lbs) and go to the 1/4 mile sometime. Plus i have free dyno sessions at the end of the build so i want to do it right and beat my mates 318.4hp SBC haha also i thought the rods were 6.760? is that true or is it the stroke and compression height that is different? because if it is 5.7 couldnt i get SBC rods and machine them to fit? would it be better to find a 194 head and machine that or use the 292 head and work that except use domed pistons? At 11:1 compression and above id have to run AVGAS or someother high octance fuel ey?
Do you mean the 292 uses a SBC rod? I reading something saying the 292 stock rod is much longer,6.760
those are other inline sixes not sbc's, but, i too, thought the 292 rod was longer than the other sixes.
Thats what i thought. Thats why its harder to build a 292 instead of 250 right? I found BBC rods at 6.80 or 6.70 just would have to get cutom pistons, or i could get custom rods and use TWR 307 pistons or use the TWR 230 pistons- same 3.875 bore i think? I was going to get the block sleeved for 4inch bore and use cheap forged 350 pistons and get them machined to fit the bigger BBC wrist pin. But thats a very costly job, also time consuming. Would love to use H-beam rods and light forged pistons. Nothing cast.
You should get the book by Leo Santucci on building 292 engines.He's a drag racer but there's a lot of good info . He says the stock rods,unique type , are forged and can be shot peened,high quality rod bolts (SBC) and resized to deal with most street applications.
i would go the other way and run the small block pin (lighter weight) and av/gas isn't the way to go! think about getting it to breathe (head work) and if you want to drive it on the street you'll want to use pump gas the compression ratio will have to be max 10:1
If your serious about the race part, you might want to look into a aftermarket crank.....a friend has some parts left from his.....at one time it was in the 8's .....but when the crank broke, there were lots of paper weights made....lol. might check with scat
Yeah, in the future i will be casting/machining my own crank for my TAFE course (College for you in america) This engine won't be ran everyday, maybe a couple of times in the month and not above 5,500 rpm for more than 30 seconds at a time. And this isnt a street enigne, i want 12:1 comp and if i have to will run water/meth injection setup. Yeah i am getting his books, just AMAZON takes a while for it to get to Australia
Yeah, the previous poster was confused or something. The 194-250 engines use rods that are 5.700" in length, and are small journal SBC size in the housing bores, and uses 11/32" rod bolts just like the 283 SBC. The 292 rods are 6.760" in length and are large journal SBC in size, and uses a 3/8" rod bolt just like the 350 SBC. Both engine groups rods are 1.030" in width while the small and large journal SBC rods are .940" in width. All 194-292 rods use the same .927 wrist pin as do all the SBC engines. The common aftermarket rod length for the 292 engines is 7.250", which will help you get a much lighter piston. You will be better off getting a piston specific for the L6 and not using a run of the mill SBC piston because they have much different valve angles and valve locations relative to the piston, especially if you run a camshaft large enough to require valve reliefs. Using a bore of .060" over is quite common for these engines, and since you have a Mexican block, it still will be quite thick at that size. On down side is that no one currently makes an "off the shelf" rod for the 292, and there is no other rod that has ever been made that you can swap into it, custom is your only choice if you want something better than the stock rod. On the other hand, there are several aftermarket companies that offer H-Beam rods and even forged I-beam rods in both 5.700" and 6.000" lengths for the 194-250 engines. One note about camshafts, the 194-250's use a different camshaft blank than the 292 engines do, and can cause you some issues if you purchase a camshaft that is not made with the correct cam blank. The 292 camshaft has notches cut into the barrel of the cam for rod clearance, even on a stock production flat tappet camshaft, as well as the fuel pump eccentric being in a different location than that of the 194-250's camshafts, so be careful if buying an aftermarket cam, and make sure they provide you with the correct cam blank. If your only looking to bet your friends HP #'s you will be a little disappointed, you should easily be above the 400 HP level with your current list of goodies you mentioned.
Dude, if i end up with half as much knowledge as you I'm going to be stoked haha. Thanks mate, thats really great info. So shall i use TWR flat tops with custom rods? because with that and the 292 head around 70cc's right? that wont get above 11:1, am i right? Or would it be better to source out a 194 head, cause my neighbour and best mate has a farm where his late dad kept a heap of old chevy straight sixes from 1940's-60's trucks from the war and that. And the clifford cam is designed for the 292 so thats a bonus. 400hp+? really??!! holy shit, people didn't believe me when i said my goal was 340hp haha Bring on 2012. Keep up the info guys, truely great and greatly appreciated by a rookie
Now I am confused. How does an aftermarket rod (which nobody makes), that is about a half inch longer work with all other parts stock??
Your welcome Hulk. A group of us on Inliners did a very extensive set of dyno tests a while back on a 292(over 120 dyno pulls), and a 250(about the same, also did a turbo install). We tested/swapped 8 different cylinder heads(even a 194 head, which always made less HP than a compararably prepped open chamber head), 8 different cams(both hydraulic and solid lift), and several different intake and carb combos as well as headers vs. Langdon's cast iron manifolds. I think you will be more pleased with the open chamber(70cc head) with 1.94" intake valves and 1.6" exhaust valves for your project. With a true flat top piston(no valve reliefs or chamfer)you will have right at 11.4:1 compression with a .060 overbore, 70cc head, a .040" thick head gasket, and a .005" deck height. Keep in mind that if you need to cut valve reliefs or if you use aluminum rods(which you will need to lower your deck height an additional .010") will slightly drop just a little compression, but you still will have a hair over 11:1 if you have to do that. Sounds like your going to have a lot of fun with this engine build, make sure you keep us posted as you start it.
Sorry for any confusion, but no one makes an "off the shelf" rod for the 292's, but many aftermarket companies make "custom" rods(both aluminum and steel) for the 292 engine. Meaning you call them and tell them your needs and 6 weeks later you get them, as opposed to "off the shelf" meaning they have them in stock and you recieve them a few days later. You still will need to get your pistons made to accomodate the longer connecting rod length because there is only OEM replacement cast dish pistons available for the 292, all others types(forged flat tops, domed,etc.)will have to be custom made.
The link that Phil1934 posted is for the earlier edition of the The six cylinder power manual. His latest version is http://www.amazon.com/Chevrolet-Inl...=sr_1_3?s=books&ie=UTF8&qid=1320688337&sr=1-3 There is a board sponsored by a guy who runs a hot six in a Nova drag car that has a lot of info and is primarily drag race oriented. There is some good gofast discussion there. I lost the link when my old laptop crashed. Start by buying one edition or the other of the book that Phil1934 and I posted the links to. It wouldn't hurt to buy one of the low buck used ones on his link to start as they read just as good as a shiny new high priced one. And go from there.
Invest in a high quality harmonic balancer. Without one you will have tough time keeping a flywheel bolted on. Safety wire, locktite nor anything else will help either
Yeah, I just got the book from amazon, downloaded it to the computer and there is some really great info in it. But it seems like you guys could write another book! haha. I shall read it all and do some research then post my final build recipe The money isn't a worry, nor the time, its just the availability of parts and making sure they all fit. But either way should really test my skills which is what i love, I really love the old hot rodders who make their own heads and pistons. Like Kay Sissel, remarkable man
Hulk, one thing you'll find awesome is the 292's torque ability. Our very first dyno pull was with a stock 292 engine as a baseline(only headers and a 4 bbl added). By 2000 RPM it was already making 300 Ft lbs of torque and never fell below it till well over 4000. And every combo we tested had over 300 Ft lbs by 2000 RPM as well. I think you'll be pleased with your combo. Keep us posted.
Yeah, I have heard they are torque monsters, should be good for my 2 door gemini that is a very light car. The only thing that worries me with these motors is that they aren't very stable at 6,000 rpm and above. And I have sympathy for things so i really want to be sure it can handle high rpms. About the compression ratio, i need a clear answer on the recipe. I want to run TWR flat-tops with a 292 head, highly ported (lump port, bigger valves etc. etc.) To achieve 13:1 compression would i be able to do that be angle milling the head and using custom rods (SCAT) to move the piston up bit?I am going to run custom aluminium manifold with either 3x2 barrels or 3x4. Probably 3x390-500 holleys. Or 3x4 holley 465. The camshaft is a clifford, the biggest one i could get The bottom end is going to use ARP bolts and have the mains doweled. Custom extractors probably 1 7/8" maybe a little bigger (Thats what I run on my Holden 202 cubic inch inline 6) MSD Chevy 6 system Igntion system The head drilled and tapped for shaft mounted BBC rockers. SBC ATI balancer, best one i can find External driven high volume oil pump All of that is going to run infront of a Tremec T56 and a 3.90 or 4.11 Diff (Already in the car)
Hulk, the 292 isn't going to be a high revving engine. One thing that is always going to be present in this engine, moreso than a 250 or smaller Chevy L6's, is destructive harmonics above 6000 RPM or so. All of our dyno tests were also conducted with only 8.8:1 compression with the open chamber head, and 9.4:1 with the 194 head, the open chamber always providing the highest HP and torque. We were able to reach 300 HP and 330 Ft.lbs. of torque with basically pump gas compression, and only 4500 to 5000 RPM. The engine used stock 292 connecting rods w/ARP bolts, and custom Venolia dished pistons. To my knowledge, Scat does not offer any connecting rods for the 292, and they don't provide a custom service(meaning they do not make things on demand). Your only choice in a custom rod will be a company like Crower, Carrillo, Oliver, etc. for steel rods, or any number of numerous companies that offer aluminum rods if you intend on using the TRW piston. The 307 TRW piston is a perfect swap for the 250 engine, but as you can see, its going to be expensive to use it in a 292 because of the custom rod factor required. The 250 and smaller Chevy L6's are a higher winding and revving engine, and can safely rev to RPM's above 6000, but they still have points at which harmonics can threaten and harm them, so don't feel you have to twist the guts out of a 292 to make power. You should still be able to make 400 HP well below 6000 RPM and have fun doing it.
I found the GRP rods are basically perfect, so can you use TRW pistons with aluminium GRP rods? without cutting valve reliefs which will harm my compression. The scat rods were the BBC ones but after close look at the specs they wont work. Any type of compression above 12:1, but below 15:1 is good. So 250 flat tops with GRP OR 307 flat tops with custom steel H-beam rods?
Whether or not you have to cut valve reliefs is dependant on too many variables to say. You will just have to degree the cam in and check all that. It is going to depend on how much your block, head has been decked, if the valves have been sunk when the valve job was done, if you advance the cam when you degree it and a host of other things. If you do go with aluminum rods, you will have to talk to them and see how wide the small end is on their rods and see if they will fit between the pin bosses of the TRW pistons. If not they may have to trim them down for you so they will fit. Also be preppared to do some block notching for rod clearance, and probably some additional cam clearance, since flat tappet cams usually have a much bigger cam barrel than a roller cam does, and when using a roller cam in a 292 with aluminum rods you need to do that with them as well. Also, Venolia has a really good dome piston forging for these engines, so if you need to bump the compression up a little, you might as well go with a small dome to get all you can(within reason). I think a flat top is going to leave you to the low side of the compression you are wanting to get, especially if you do have to cut valve reliefs.
Ah yeah, might have to get in contact with Venolia. I will probably go with the Aluminium rods so thats another person i will contact, plus clifford. They don't tell you how much is involved in Automotive class haha
Since you are far away from cheap replacement parts you should be aware that the early forged steel crankshaft with two counterweights will set up harmonic vibrations at high RPM and will grenade the engine. I would suggest using only the later iron crankshaft with four counterweights and keeping the speed around 5,000 RPM. Change the rear end gears to take advantage of the torque. Don't try to build more RPM than a small block V8. OK, that is my unasked for advice.
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