4brl Intake for a 260....Does anyone make one? Am I crazy?

[silent_orchestra]

Ok, I was wondering if anyone made a 4brl intake for the 260 Olds? If so who? And where can I get one?

I'm looking to dress my engine up a bit in my '80 and think a nice Aluminium intake with a small Holley or Demon would look great with a set of Offenhauser Valve covers, and maybe headers and a nice exhaust too.... Not going crazy at all, just looking to free up a few extra and much needed ponies, and clean up the engine compartment a bit.

Thanks for the help!

 

[Oldsmoletick]

Unfortunatly there is not an aftermarket 4bbl intake for a 260, there is a way to put one on, but that requires swapping heads out, machine work to the heads, 260 heads have very small combustion chambers, so any other head would have to milled in order to retain the 8.0:1 ratio. So it is possible, but the cost of doing it would probably out weigh the results. It would wake it up a bit but, you may be further ahead swapping out the 260, for a 350 or 307 (it may be a bit cheaper to swap engines if you find a good running donor).

 

[n33no]

I'm not sure. But I think this might work.

http://www.jegs.com/i/Edelbrock/350/3711/10002/-1

 

[dan2286]

I'm not sure. But I think this might work.

http://www.jegs.com/i/Edelbrock/350/3711/10002/-1

It will bolt on, but won't be an upgrade. I believe the 260 ports are very small and will not work well with any other small block intakes.

Remember, the 260 is worse than a 307. They are not worth trying to get power out of. If you want a cheap power upgrade, get a 307. Most people will give one away for free or less than $100 :lol:

 

[joe_padavano]

I'm not sure. But I think this might work.

http://www.jegs.com/i/Edelbrock/350/3711/10002/-1

It will not. The 260 has unique intake and and coolant ports. No four barrel intakes will seal properly and even it you did manage to make one work, the port mismatch at the head surface would cause turbulence that would likely result in DECREASED flow. As noted, it makes zero sense to do anything to the 260 except to replace it with a 350.

 

[silent_orchestra]

If I wanted to swap engines I wouldn't even bother with a 307 or a 350... I've got a 425 and a 455 that need homes (the 425 was going to be for my truck, but me and the truck aren't having a good relationship right now) I just figured if I could easily get a little power from it that'd be cool...But I'm not really to worried about that.

What about an exhaust? It's just little to quite....Okay it doesn't make any noise at all... A little would be nice.

 

[kustomkyle]

True dual exhaust, headers and glasspacks. Probably the best thing you can do for performance. You can do more with bigger engines, even 307s, but who cares. Maybe you can modify the 2-barrel to add some horsepower. I've got a book on Rochester carbs that has tuning info. on Dual-Jets. I'm not a mechanic, but I've been slowly gathering ideas for the 307 in my car here. Basically if you mention 260, 301, 305, 307,etc on this website you will get responses with "swap to a 350, 400, 403, 455", and so on. You will have to skim through it all until someone gives some decent advice on the engine you are asking about. Some of the B.O.P. purists have the best advice.

 

[tboles]

General Information

Buildup
4 BBL Modification
If you want to use a 4 BBL on this engine, you must change the heads to 5A castings as found on 307 Olds motors. If you mill them .030-.040, then you'll gain back compression. Then you can bolt on the Edelbrock Olds performer intake. A set of Mondello heat riser plugs installed in these heads will make more power. Just drill a 1/4" hole in each plug to get back just enough carb heat. The Mondello 15-100 cam works great in those little 260's.

The heads on the 260 are designed for the 260's small displacement. So, in order to increase torque (I'm assuming) the intake runners are 1/2 the size of conventional runners. Unfortunately the way the accomplished this was to fill the bottom half of the runner with material - BIG flow stopper! Not to mention a good spot for fuel to puddle.

Being undaunted by this (plus I had already purchased the intake and carb) I went forward with the installation. What I found was that the 260 required me to do a LOT of tuning to the carb to keep it from bogging out of the hole.

I had the motor tied to a TH-350 and 3.42's. After getting the carb staightened out, had to rejet and fiddle with secondary opening rate, the combo ran noticibly different. Part throttle was very similar (slightly stronger) but where the big difference was, was in the top end. I had put an "RV" type cam in it, PAW special, and it definitly liked the 4 barrel over the 2 barrel. Unfortunately never had the car to the strip either before conversion or after, but it did make a very marked improvement. Gas milage was about the same for both combos as long as I kept my foot out of it (aprox. 17mpg).


didnt know if you had found this info already

 

[KrisW]

Okay, now has anyone taken the early small port 307 aluminum quadrajet intake and port matched it and the 260 heads to use that? That and a stock late 70's smogger 350 or 403 cam is a great budget combo for your ride. Those cams are absolutely useless in their original engines, but your 260 will benefit from just a slight increase in cam that they provide. You can run a 500 Carter AFB or Edelbrock, and you only have to do a little modification to your 307 aluminum intake to make it work without an adapter. If you have plenty of hood clearance, then use a 1" spacer/adapter. Ever little bit helps! I also made an EGR block off and plugged the exhaust crossover. I didn't drill through to allow any exhaust to get in and I was fine, since my choke worked. You can also use a quadrajet designed for the 301 4bbl firebird or 305 4bbl firebird from 1980-81 (or really any small block smogger quadrajet) and then change the jets and metering rods to match if you like quadrajets better.

My 260 in my X-body Omega could squeeze out 20mpg with that. You can use the 1 5/8 headers designed for the 307 or olds 350 in the G-body for exhaust.

The port matching of the intake and heads is really required. I suppose you could use a 350 intake and just gasket match the 260 heads so that you eliminate reversion but you would most likely lose a ton of port velocity and your engine would be a dog. I suggest the small port 307 intake with mods.

Good luck!

 

[olds307 and 403]

Another possibility is the Edelbrock SP2P intake, there is a guy who will sell you one on ROP/OP. He bought the intake sight unseen. These intakes have small triangle shaped ports and are low profile. The make excellent part throttle torque and fuel economy. My 350 Qjet overwhelmed full throttle but part throttle was excellent, like port fuel injection. Definitely add the Mr gasket 1" phenolic Qjet spacer. A Canadian non CCC 307 carb would be perfect for that motor. I had one, that when headers were put on it had a lean backfire, part throttle.