I need any advice you guys can give as to a good choice for an inline 6 I can make into a mean tire turner... What chev motor has the best performance potential the 235 family or the 250-292 family???
The later chevy 6s have more potential for power. Do a simple search - lot's of info around here. Also check out the inliners forum .... http://www.inliners.org/ubbthreads/ubbthreads.php/ubb/cfrm
If you want crazy horsepower for a Chevrolet go with the 292. If it was a Ford i'd go with a 300. If you were going to put it on a track and needed to run it at high RPM for hours one end, i'd go with a shorter stroke Ford 240. Check this video out for 292 Chevy performance. www.mighty6.com http://www.youtube.com/watch?v=C1CPD17Pwzc www.inliners.org has a racing pictorial section... some pretty wicked inliners there...
thanks for the info guys! I was thinkin a potential B-ville project so I'm looking for some good Hi revving but still streetable power... I know i know you gotta choose street or race but how about the best you can give me for an ideal mix...
I've got a 250 in the 48 and am replacing it with a 292 but it isn't set up for extreme speed. just a strong reliable motor that I can cruise at freeway speeds for hours on end without problems. There is a lot written on inline sixes you might start here http://www.inliners.org/
inliners.org - as has already been mentioned has many good articles and a wealth of information in their forums sections. parts vendors for inline sixes: http://www.cliffordperformance.com http://www.stoveboltengineco.com http://www.speedwaymotors.com pre 1959 chevy truck information, tech section... some of the engine stuff may or may not be helpful: http://www.chevytrucks.org/tech/index.htm tech tips section of stovebolt.com : specifically the engine section has various articles: http://www.stovebolt.com/techtips/ if you check out the 'forums' and the 'hi-po shop' there is a lot of information in older posts there for getting power out of inline sixes. -W
I have built several and been involved in others at the design and machining level. The 250 is a very practical & powerful motor when done. It lends itself to a very inexpensive biuld since it can use the 307 pistons for a compression gain . head work is where to spend some time. Valve size can be too big and cause shrouding (ie 2.02) I use 1.88 or 1.84 . Built one for Len Collins 39 chevy coupe. It has a 350 turbo trans. Len replaced a V8 with it and told me it is faster and far better on fuel. Say he gets rubber in all three gears and yet can drive to TO and back without buying gas. He has a Stovebolts intake , twin carbs and split manfold on it. I have worked on and done the early chev sixes as well. nothing wrong with them but the 250 is a much more modern engine . The 292 is a torque monster but with the 250 being such an inexpensive and reliable build it sems hard to justify the extra expense to me. Others of course may feel different. Have done Ford 300s too. Best engine Ford ever built in my opinion. Bob Gauley of ONDR has been running one we screwed together in 1993. He even ran it this weekend. It is in an old style t bucket altered and despite being a bit heavy runs mid-high tens. Me i am a slant 6 man of course. Also though I am a huge fan of the Jag six especially those from the 60s and have built one for a friend as well. They are an exremely well designed and exoticly built engine with a huge potential for power. Always thought a Morris Minor gasser with a Jag six would be really cool. Don
...and then there's this from the 292 camp: http://www.customdesignperformance.com/leo/leo.html A (the?) definitive book on making serious power and torque gains with the 194-230-250-292 Chevy sixes - Chevrolet Inline Six-Cylinder Power Manual - is arequired read for anyone contemplating a first-time Chevy inline build, IMO. With fairly mild build and a turbo, I'd expect a street-trim 292 to pretty easily hit 300 horses...maybe more. Coupla guys here on the HAMB sell hop-up parts....try talking to tlowe since he runs a turbo'd 292 in his street El Camino and sells copies of the manifold he built the car with.
Having run at Bonneville in the XO and XXO classes it would be my advise to look for a 302 GMC. The 235-261 Chevy is to small to run in a 325 cubic inch class that will have 320 inch GMCs in it. The late Chevy, while a very good motor, runs heads up against any V8 in it's cubic inch class. The V8s have quite an advantage in aftermarket support. If you don't care about all that then the 250-292 late model is a better engine. The 235-261 engine is plenty cool. Inliner #0009
So then whats up with the GMC stuff i.e. the 270, 302... are they not as stout a platform? The 302 does have the advantage of square displacement (4in bore 4in stroke) These are more the era I was hoping for but is their power potential less than say the later 250-292 family?
Well there was a lot of progress made in engine design in the 25 years or so between the series starting. Lots more port area in the late model. 7 mains as opposed to 4. More modern combustion chambers. Just time marching on.
I don't get anyone using a inline 6,less your racing in a class that said you must. 4 less $ ya can have manytimes the power with a V8. I worked on many 6's for class racing and won lots,none of them have heads that breath much no matter what ya do,so cams and inside work are a big wast dollar for dollar,yet some can look nice with carbs,headers and chrome,passed that your trashing your $. Just have some fun with it,if your going 6. We laft at 4 and 6's in the 1950 and 60's.
6inarow thinks it sounds like I'm saying early motors have 7 mains and late motors have 4. I don't know where he is reading that, but it is a good indication of what can happen if you fool around with 270-302 GMC motors to long. After a while you don't much care how much power someone can buy from the Summit catalog. You just like GMCs. Don Ferguson went over 300 unblown on the salt with one. Not to shabby for an old dump truck motor.
bellhousing mounts are the same. Right side motor mount is in a different spot on the 292 versus all the others, because the distributer is in a different spot on the 292. The Jimmy's are the way to go if you are looking at Bonneville. A 250 if you want something different on the street.
dana barlow the 194-292 heads and be made to breath Pretty well.A 194 head with a 1.94 valve can flow OVER 250 CFMS I know we set a New record last yr in Bradenton with that head on a 250 the car ran 9.16s @ 142 plus
So it sounds like a 250 for a cheap street motor and one of the jimmy's for a higher top end setup... What about turbo set-ups? Anyone on the up and up there?
id say the gmc 270 with the lumped piston and large port H-head,3carb set-up and turbos set to 25-30 psi of boost for the best power...i gots it ....Kick ass!!! is all i gotta say
run a short stroke 235 with a high duration cam and a 12 port head for high revvin. Aluminum slugs work best as well.
I would have to consider the 250 Ford. Mostly because of head availability. There is an aftermatket cross flow head and the Aussie head The 240/300 have lots of good speed parts available but suffer from breathing problems. Even a light cleanup on the ports will really pay off. I have read about some home made heads by cutting apart 400M heads and furnace brazing the pieces together. There is a crossflow in the making for the 240/300 but it seems to have bogged down when it went back to the casting foundry a year or so ago to get purdy.
If you really want to be different, there's always a Hudson 303. Build it with an Edmunds 2x2 intake and a factory aluminum head. Probably not cheap that way, but it would sure be different.
If you are going to show the car the L6's get more attention than anyone's V8 or even flatheads. They look like they belong under an old hood. I don't know how many people have remarked that my car has the original engine. I just kind of nod and say its (292) similar to the original (232).
Golan engines screws together a couple of strokers off of Jeep 4-liter cores that really pour out the torque. The regular AMC 6 has seven mains and plenty of parts support.
Fords 300 will put out big numbers and live through a 7K blast. there have been some articles on how to build and I read a blog about turboing an EFI.