Folks, I am trying to mount a Nicson Intake Manifold on a 53-55 Corvette Exhaust Manifold on a 261 cui Chevy engine. The Nicson appears to have a 216cui bolt pattern on the heater block and does not line up with the Corvette manifold holes. Is there an adapter to make it fit? It's for a Chevrolet Fleetline Aerosedan project. Thanks. 1947 Chevrolet Fleetline Project
Looks like the Vette's exhaust manifold is for a 235, which the Corvettes had and which is why the holes are slightly off. You need a 235 intake or use Fenton headers.
Bummer. Probably not worth the risk or expense, but I wonder if you could fill the bolt holes on the intake with weld then redrill and tap to match the exhaust?
I don't know of an adapter for the heat riser. Don't forget 216 have smaller ports and use smaller rings than a 235/261. I think your best bet is to trade 216 Nicson Intake Manifold for a Nicson 236/261. I may know someone with a 235/261 Nicson. Please fell free to contact me. A little show and tell, my Sharp and Corvette Exhaust Manifold going on my 261 in my Model A truck. A link to the build- http://www.jalopyjournal.com/forum/threads/my-261-chevrolet-6-in-an-east-coast-model-a-truck.976419/
The Vette engine was a 235" Blue flame. I seriously doubt that Nicson had Corvette in mind when they cast the intakes as the corvette came stock with twin pots. I guess that I would do one of two things with that setup, I would either modify it to fit or I would sell it to someone else and come up with the proper matching setup. Given my options I would much rather have an original Corvette setup with the side drafts and proper exhaust than the Nicson. Nothing against Nicson they produced as good an intake as anyone from the era it is just quirk for me.
Hi. My thoughts on this is that an adapter will raise one manifold and then the ports of the intake & exhaust will no longer be on the same plane. For an adapter you might have to mill the manifolds surfaces thinner to make room for the thickness of the adapter so you can keep the ports on the same plane. Can you simply ream the holes so the bolts will align? Then all you would need to do is either modify or make an new heat riser gasket. If this will work it would be the easiest fix. My Clifford intake shown in my Avatar of my 1957 235 uses hot water in a lower chamber for heat risers and the intake & exhaust manifolds do not connect at all. But because of the added lower chamber the only exhaust manifold that will clear intake is the shorty tube headers. Fenton's & stock exhaust manifolds will not clear. Post back with a photo of whatever solves your problem. Good luck, Jimmie
Thanks for all of the replies. I'll definitely read through each reply. Did they make Nicson intakes for 235/261? Sent from my SM-G925V using Tapatalk
Be aware the 216 & 235/261 heat riser flanges are machined at different angles .... why not just buy an intake that fits ?
I'm sure it exists. I used to have a nice in manifold for an International. It was cool wall art and totally useless to me otherwise her wise
I think it's tough to find a aftermarket 235 intake, other than Offy or Fenton, because the Mouse Motor was release one year after the full pressure 235 engine so naturally, Speed manufactures started producing parts for the Mighty Mouse. That's my 2 pesos.
It's hard for me to say. Most of the intakes I've seen are for 216s. If I were in your shoes, I would just make sure it's for a 235. I always go by the carb mount spacing. 235 is slightly larger than the 216. Your other choice is to go with a new Offy (both the 216 and 235 are available) or the Fenton which is for a 235.
Also keep in mind that a 235 dual intake will be for 2x 235 carbs, which are better for a 261 built for racing and high rpm. My 261 is built for the street with a 254 cam and uses a McGurk intake which came for either 216 and 235/261 ports but always used 2x 216 carbs. They also had a baffle in the center which distributed the fuel more even to all cylinders. I think the only other 235 dual intake using 216 carbs was Tattersfield. Look for either one of these if it's for a street engine, or 2x235 carbs will never work right.
My Nicson has 235 runners and uses the 216 carbs. I have a Sharp as well. Not sure what it uses though. I'll measure and let you know. Is there an advantage to running the Corvette manifold? Better performance? Different exhaust note? If not then I'd slap the Fentons on it. Why not use what you have? You'll save time and money.
My friend designed an adapter between the two manifolds. I got it 3D printed for prototyping and it's looking very good. I plan to machine a final aluminum piece. Thanks for the feedback
You are correct, but I have seen '54s with two ( more than one at the same show). I never made the correlation until just now, I wonder what the deal was with that? I looked and never gave it a second thought.
This guy has a new 235 Fenton intake for $179. I don't see why you wouldn't buy a new manifold and sell the old one, and get one that fits. http://www.ebay.com/itm/FENTON-DUAL...OLET-235-INLINE-6-CYL-W-LINKAGE-/291654878007
" '54s with two". Most likely the car was a '54 with a stock air cleaner - they're stamped sheet metal with 2 round pot looking elements ...
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