I need help finding a manifold for a 250 inline 6. Haven't had any lucky when I google it. I believe its what you call a split maifold. Part of it is made on the head and the other half bolts to it. Wondering if I could replace the head with a different one? Any help or advice I would appreciate.......by the way cool forum.... <!-- / message --> <!-- / message -->
Not sure I understand what you are looking for. A split manifold is an exhaust manifold that would keep the spent gas from 3 cyliders separated from the the spent gas from the other 3 cylinders either by using two manifolds or having a partition in the casting of a single manifold. It sounds like you might have a cylinder head with an integral intake manifold built to meet smog regulations. I think you can swap this for an older non smog head without modifying the block. Got a photo ? that always helps. Oh , welcome to the board!
Intake is formed to the head and exhaust comes off. Here is a pic of one similiar...amplizine.com/featured/gm-250-cid-inline-6-an...
..........reading between the lines, sounds like you might want the exhaust manifold for the 250 with the integrated head. If not, figure out what it is that you want and enlighten us. A picture of your setup would be a great help. Anyhow, take a look at this, even if it don't fit your needs it'll be a short start on educating yourself with the differences................ http://cgi.ebay.com/ebaymotors/4-1-...r_Truck_Parts_Accessories?hash=item3a59c3c832
Some manufacturer - I think Nash - also did have an integral intake manifold where the top half that contained the carb mounting flange was fastened to the lower half of the intake. But I don't think any 250 Chev is like that.
Your intake is actually part of the cylinder head, and the exhaust manifold bolts onto the bottom of the intake part of the head. If the "intake" is cracked, you need to replace the whole cylinder head. You can convert the engine over to a more traditional cylinder head with separate intake and exhaust manifolds. You just need to find an older head and manifolds. 194/230/250/292 heads all interchange. When getting manifolds, Just be aware of where the exhaust outlet is, as not all of them were the same.
29nash is right. It is and integrated head. Can be swapped for and earlier 250 head. What you have is part of the exhust manifold is cast in the head. Lots of problems for me when I had one. Swapped out for and earlier head and used a 292 truck 3 bolt at flange manifold. Larger flow and 3 bolt, car manifolds used 2 bolt flanges. Been there, done that and still have the parts. PS make sure to get a head with hardened valve seats or have them installed when you have the head at the machine shop.
Those integrated inline six heads are junk. The junkyard guy told me if you ever let 'em get hot they're history. Cracks right across the crown of the combustion chambers in #2, #3, #4, told me he wasn't kidding. Then he told me used heads had a waiting list. I sold the car to my neighbor who turned it into a V8 car and drove it for the next 10 years.
Whatever the case if your head looks like this^ Even though you lose about 15 hp, it's better to junk it and get one like this. You can buy a rebuilt one for about $250, they are fairly plentiful. Of course, then you will also need different manifolds. There are a couple of aftermarket options, clifford and offenhauser that work, or the stock manifold for the one barrell Rochester.
Thanks everyone for the replies...29NASH right on the money. Do I just search rebuilt head for inline 6 250.
I don't remember if it's Patricks or Langdons that sells rebuilt late model style 194, 215, 230, 250, 292 cyl.inder heads for a very good price. I gave all my catalogs away when we went the V-8 route. Maybe someone else here has one of the catalogs and can elaborate. Butch/56sedandelivery.
Like a dumbass I just pulled my parts truck out and realized the engine HAS an integrated head! ARGHHH!@@@#@ Now I am looking for a head.
Thanks, them and Napa are damn proud of them tho. I will start looking locally. My engine is a good runner so I can bide my time until I run across one. I was really bummed out when I realized that this afternoon. Was ready to scrap the inliner altogether, then I ran it through my head. Went out to eat for Mothers Day and I am good with it.
another way to do it is to machine the intake off then make your own intake and exhaust. that way you have a 12 port head on the 6. another way is to cut the end cylander off of 2 sbc heads and weld them together. that makes a killer head for the 6. i have a pair of zz1 heads that lost a valve and luck would have it they are the ones that get cut off.
OK, now you got me interested! Sounds like you have done this with a machined head? New to the late sixes, how far off are the SBC water passages, bolt hols etc? I need to buy Santuccis book. I assume he covers this? thank you so much.
Anyone messin' with second gen Chev sixes (194, 230, 250, 292) should have Leo Santucci's book. Yes, it covers cutting and welding small block heads to go on a six block. Looks like it's fairly involved. You're not likely to run across a 194 head, they're pretty rare. Not sure you'd want it for a street motor, the chambers are very small and yield pretty high compression on a larger displacement motor. They were early sixties and as such wouldn't have hardened exhaust seats. And yeah, Clifford has all sorts of good stuff for these motors.
Ford Australia already did that with a factory 12 port cylinder head. Google "250 2V head". It came on the 250 CID six, with a removable aluminium inlet manifold and two barrel carby. This is now ancient technology. The later six cylinder double overhead cam engines were better. And the current 24 valve DOHC engines better still. If you really want to fly, that same 24 valve DOHC engine now has a factory turbo and puts out 415Hp and 415ft/lb of torque. Of course none of this exists in America, Ford only did it in Australia. http://en.wikipedia.org/wiki/Ford_Barra_engine
Santucci's book goes into a good amount of detail on several versions of the v-8 head adaptation.It would run pretty strongly in a light car. Yupper, it is involved, but the returns are probably worth it if you want an engine that everyone will say 'Okay, this looks like a Chevy, but the head's wrong...Is this thing really a Packard? From World war 2?' The version that would really screw'em up would be the one using the Ford Cleveland heads as cannon fodder. I personally think it'd be smarter to start with the bare World Products heads, and know for sure that you were starting with a good, clean product instead of a greasy salvage yard special. Less cleaning and mucking about...Clean cast iron is LOTS easier to weld on, anyway. Speedway Motors is where I got my copy, for about $15 USD, a couple years ago. Mike
the hybread head is covered in the book. it is a major not a done in an afternoon. another head would be 2 181 mercruser heads welded together the bolt holes and the push rods are better in that head. it too is in the book.
I just wish the intake manifolds could be had for reasonable prices. Even used ones are selling for $200.
I run a mid 70's 250 without inter. head (their junk) in my 29 ford roadster truck with a 350 turbo trans and a 373 gear. works great. Plenty fast and powerful. my motor has around 100psi compression and burns a qt. oil per 100 miles but never fails to start and is a blast to drive. It's getting a rebuild this winter. There's plenty of speed parts for the 250 also. cliffords, speedway are a few that have parts. I'm going with an offy 3 single barrel carb intake ( it will look more traditional) and a stock motor. Don't like 4 barrel intakes on a inline. I'm going to use rodchester monojet carbs a only use the middle one, the other 2 will be dummys. Look at the old gmc in line 6's and try to duplicate the look.