Hi, I wanted to know if anybody had any pictures of of modified stock chev 250 intake manifolds? I think it can be done, but need some pictures to convince my machinist to help. For those who have read my previous posts I had to give any hopes of getting newer chev 250 parts. In Guatemaula they did not have any chev 250's.

There is an internal cavity surrounding the single bore opening in the intake, and enlarging the bore to accept a 2 bbl will break into this cavity. So it probably wouldn't be a good idea to try it. It would involve having to fill the cavity with some sort of epoxy and will likely cause you to loose your intake heating from your exhaust manifold. Plus, don't know how the epoxy would last in the long term.

How about using an '81-'83 250 truck intake?? already a 2bbl.

Not exactly the same but here is a modified Johnson intake:

http://i965.photobucket.com/albums/ae131/strokersix/DSCN3475.jpg

Machining and modifying the cast iron OEM manifold from a one barrel to a two barrel configuration. The attached original photos would not pull up for me now.


https://www.inliners.org/ubbthreads/ubbthreads.php?ubb=showthreaded&Number=63274

The varajet carb was only used on the integeral head. just to make sure, I have done a cross country jy check for a 2 bbl manifold; no luck. Periodicly I check online for used manifolds no luck. I have now acumalated some stock manifolds.

Sent PM with pictures as I could not figure out how to post pictures on thread.

I thought it was you that had modified an intake for a 2 bbl carb. Not sure if he could do it with a factory 1 bbl intake though because of the cavity surrounding the carb area. If he could find one of those intakes like you have there that would be his best bet.

I,D GET A OFFY 1X4BBL EASY TO GET WHAT YOU NEED THERE

I am sure that the 4 barrel Offy would be straight forward... But I don't have one. A semi retired foreman at work has a home machine shop, where he trys to reinvent the wheel. Hope fully Nobby can do something for less than a flat of beer.
There is a swap meet coming up, I will check for more suitable manifolds then.

...Oh also the Nova will only see fair wheather so less heat shouldn't be to bad, (with a machined stock intake).

Hi, thanks for the thought but your pics didn't come thru.

I'd like to see the pics too.

Here are some before and after pics of the stock 1bbl manifold that I modded.

Backstory, I wanted to retain the factory manifold but have it flow better for my turbo application. So I milled the factory 1bbl hole larger to fit the opening area of a Holley 2300 2bbl. Yes, to my surprise, there is a sleeve and cavities. At this point I had to fill the cavities, so out comes the JB Weld! I made some forms on the filled with JB Weld.

Milled:


I check it after around 500 miles or so, to see if the "fill" was maintaining shape and not deteriorating. It looked the same as the day I put it in. Since then, I ran over 2000 miles on it, before I swapped it for an Offy.

Current:

Thanks for posting the pics. This manifold looks like it would work ok. Did you notice the loss of heat? How come you swapped it out for the Offy?
Thanks Jason

I noticed no difference with loss of heat. My setup is a little different than a N/A though. I am running a turbo, blow thru carb... So I removed the heat riser in the exhaust manifold to get maximum flow.

While this manifold flowed twice the stock one, because I am turbocharging, I wanted to get max flow on the intake also. The Offy's spread opening allows that. Other than the opening, the manifolds look exactly the same.


Boucher'

Hi Boucher, thanks for the info. I am thinkingthat the stock manifold will work just fine considering my application.
Jason

nice engineering pal

250 eng update: A while ago I scored an offenhauser manifold, with their adapter plate & spread bore adapter for $150. I am planning on putting on putting on the varajet carb that I have. Still have to assemble eng to complete the rebuild with head studs & new balancer.