I have a newly rebuilt Chevy 250 straight 6. I had to replace the old intake manifold and went with the Offy (5416) which is designed for a quad carb. The problem with this manifold is that it seems to be designed to require the carb to be side mounted which means I would either have to get an adapter plate to rotate it 90 degrees, or even worse I need to get very creative with new linkage (cables and pulleys running all over the engine compartment) which I really don't want to do for a variety of reasons. I see they make tons of adapter plates but none of them spells out whether they cure this problem and most if not all of them look like they stick to the sideways orientation. If you are familiar with this manifold, you know that the screw holes for the carb mounting plate are just slightly off square so you cannot simply rotate the existing mounting plate. I have seen from some of the comments on Summit Racing that others have had this problem but no one has mentioned a solution. Right now I have a Rochester 2G on an adapter mounted with only two diagonal bolts because I can get those aligned and tight without a vacuum leak but I doubt I can do the same for the Edelbrock 1405 which I already bought not anticipating this problem. Thanks!
I think you need to supply some pictures,I know that manifold and a four barrel bolts on.linkage may have to go to cable instead of mechanical
Oh it bolts on no problem if I turn it sideways but then the existing linkage is perpendicular to the carb. If I can bolt the carb on the way I want to with the front of the carb facing the front of the car (like on a SBC), then my existing linkage is in the perfect location to just hook it up and go. I thought about taking pictures but it means removing the Rochester and I just got the damn thing going !
Same issue with the Clifford intake manifolds. But, I believe THEY make an adapter to remount the carburetor "correctly". That might solve your problem if their adapter will fit the Offy. I am Butch/56sedandelivery.
Not super helpful but here is a picture of the offy and a picture of the bottom of the carb. Imagine that the mani is bolted to the motor and is positioned as it is in the picture. The mechanical linkage comes out of the firewall right at the right corner of the mani, pointing in same direction as the length of the mani. As you can see from the bottom side of the carb, the mounting holes are orientated so it faces sideways when aligned on top of the mani and the two linkages protruding from the ends of the carb also point in the same direction with the length of the mani. This means in order to make the accelerator open, the linkage must come at the connecting point on the carb from a perpendicular direction. OR I could rotate the carb so the point of connection and accelerator action is orientated in the same direction and location as the existing linkage.
I just looked at the Clifford on line catalog and they have an adapter but I just cant tell if it will let me rotate the carb. It looks to me like it won't.
Well that makes sense. However, I wonder if the performance would really suffer enough for me to notice since I am just running it as street.
seems like one bell crank and a section of small rod or switching to a cable would solve the issue. What am I missing?
That's the setup I am planning on putting on my 292 and while I am running a cable linkage I would think that there is linkage available to get it to work. Looking at the intake in adds it looks like there is a bellcrank in the kit plus rods and rod ends to fab linkage but I'd think you may have to do some of the linkage fabricating on your own but that is part of hot rodding. As others said the balance between the front and back cylinders at an idle seems to be a lot better with the carb mounted sideways rather than the traditional mode.
Is that an adapter that is already screwed to the manifold? If so, could it be removed and an early small base 4 bbl carb used? I'm unfamiliar with inline stuff. Just wondering
Your suggestions got me looking at the Lokar stuff and it is probably the solution. I guess the problem for me is that if I could turn my carb, the existing linkage is a perfect setup and if I can't turn the carb, then there is very little room to add brackets and mount cables to the pedal, but not impossible. Thanks!
I have a 292 with a Clifford manifold, carb turned sideways and cable throttle. works fine. no pics though.
The four barrel on the 235 in my '51 Chev is mounted in conventional position (like a V8) to a Clifford intake. I've had no problem. I asked Clifford about the sideways versus conventional mount and they said so long as you run engine coolant through the manifold, the fuel and air will atomize properly. You do not always have to mount the carb sideways. I do have a cable throttle connection. Here's a photo:
When I ran a single 4 barrel, I bought a 1 inch aluminum carb spacer an drilled and counter sunk it to fit the carb running front to back. It has to be solid aluminum, not cast with voids as in the cheapies. don`t know about heat transfer as my 292 doesn`t see street duty. I think the major reason for the carb mounted sideways is to get better fuel distribution on a street type application which is a problem I have encountered in a low velocity application
You really don't have to get too "creative" with the linkage. You just buy the linkage from Offy. it is just a bell crank setup. Same as they use with a 2x4 V 8 setup that uses sideways carbs. There is no reason to reinvent the wheel, the linkage from Offy won't cost you any more than a carb adapter. I ran this same basic setup on the 292in 'my '41 Chevy way back when only with a small Holley and loved it.
Just an observation, the Offy manifold for that application is really restrictive. Consider a Clifford if you can. They are on E-Bay all the time... Good luck.
Went with the Lokar cable and bracket. Was siprisingly easy and already had a suitable hole in the panel for mounting it. Had to 180 the carb pointing front towards valve cover to make it work but it was definitely worth the trouble. Runs great! Now I need opinions about needle/seat calibration.
I'm running an Edelbrock and a Clifford on my 250. No water heat, and just the out of the box settings, etc. I used a cable and pedal from Speedway (the Problem Solver?), and like I said, just bolted it on and went down the road.
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