I bought a Elderbrock intake 2711 an Elderbrock carb 8101 to be installed on my 79 cutlass with the 260 V8 . Is it possible that I can change my old intake that was leaking to this setup with the Elderbrock intake an carb ? I sold these cars when they were new an now I'm restoring a 79 cutlass with a few changes . I would appreciate some one to help me with this change over !

 

Only a 260 intake will fit a 260.

260 intakes have smaller ports and a slightly different configuration, and are the only intake that will bolt up to 260 heads.

260 intakes will only accept the DualJet half-a-QuadraJet carburetor.

If you wish to modify or improve a 260, the only way to do it is to replace it with a different engine.

- Eric

 

X2 won't fit

 

We'll the 2711 Elderbrock did bolt up to the head an the mechanic said that the ports were only 2cm difference an the new pan gasket metal would make up the difference . We will know tomorrow if it will work

 

2cm is about ¾".

We are all very interested in hearing how that engine runs.

- Eric

 

what are you goals for this set up with the 260 if you don't mind me asking ? the 2711 are recommended for 307 and up small blocks but anything is possible with a bridgeport mill and a die grinder. Good luck with the fitment and performance your hoping for .

 

Well my cast iron intake was leaking so I thought I would replace it with a new alum intake an 4 bbl carb. If this doesn't work out.....does any one have a good 260 cast iron intake for sale. I was hoping to drive it a lot this summer an go for a BBO later.

 

I may be mistaken, but I believe that all 260 intake manifolds were aluminum.

- Eric

 

I am new to this forum but not to oldsmobile I have been a salesman most of my life . I'm not a mechanic so I asked the guys I know are Chevy fans. All I have been doing was get my 79 cutlass restored. I painted it in December an done all the mechanical things getting it running. Been setting for 7 years. I got that done in November an than painted it diamond white with black top an interior an was butting my sport 15 wheels with BF Goodrich radials. We'll hast makes waste so I will be looking I'm sure for a cast iron intake for the 260 V8. I did go to car-parts.com an they ask if it was alum or cast iron ...no alum but had 3 cast iron intakes. I will know tomorrow ! Thanks again for your help I'll keep U posted .

 

A port mismatch, especially if the ports in the head are smaller than those in the intake, will create a dramatic flow disruption that will pretty much negate any performance benefit from the upgrade.

 

http://www.hotrod.com/techarticles/1...e_260_olds_v8/

 

Unfortunately, that Hot Rod article provides essentially zero information.

Also, the photos in it are of 307 heads.
Photos of 260 heads would be far more enlightening.

- Eric

 

I went by my mechanic an he got it running an had no issues but that was early this morning. They said it ran smooth an was finishing hooking up lines etc. tommorrow I will check it out. Like I said earlier my intake leaked an wanted an up grade carb. My old intake was alum but was deterating so I choose the cheaper way. If it is a waste I will change to a GM replacement Motor with 3 yr/ 100,000 mile warranty. What do U think ?

 

Please refer to the INTAKES thread here for photos of the #1 casting iron 260 intake used in early production. PN 550559
MANIFOLD, Intake Manifold, Iron, 2-bbl, Casting ID = "1"
1975-76 260 2-bbl [faux 4-bbl "Dual-Jet"] with puny ports
1st year of issue- before AL "A2" intake developed
Heater Fitting Threads LARGE [3/4" NPT]
CD PNM: PN same as Casting Number.

Most were the AL version which is A2, PN 22503085

As for options, I would imagine the A5 common 307 puny port intake would make a great 260 4-bbl intake, and scrap priced.

Next best bet would be the otherwise useless old Edelbrock SP2-P intake with small runners, but it may have larger ports at the head.

 

Anyone could make a mistake is the 260 a 305,307 or what if your not mechanical inclined U would think the 260 was a small block 307? But is it . Just a common Joe would think. I remember selling these Cutlass an they where hot sellers. By the way I have owned 7 oldsmobile in my life time an love them an are usually trouble free. So what do we call the 260? We always referred to these motors as 327 or 350 . I can't remember anyone say it's a 260 !

 

[QUOTE=pdqbob;682721] So what do we call the 260?




A dam good yacht anchor I had a 260 in the first 1976 oldsmobile cutlass supreme I purchased back in 1982 . I was 16 my first car no power but it never left me stranded. Paid $2800. for the car and it got me thru my 5 years of apprenticeship as a Toolmaker.

 

Chris, I don't want to sound like an idiot, but I've searched for this thread using both the VBulletin search and Google search, with various terms, and still haven't found it.



I'm sorry. It may just be me, but this entire post makes no sense to me.
I mean, I literally can't understand what you mean.

Olds never made a 327. That was Chevy. So was the 305.
The 260, 307, 330, 350, and 403 were all Olds smallblocks.

We call the 260 the 260. Unless I'm missing some obvious meaning, your question is nonsensical.


What Olds motor does GM make and warranty nowadays? I mean, really, none of this makes any sense.

- Eric

 

[QUOTE=76olds;682732]Yer givin' it too much credit. It'd be a damn good rowboat anchor, as a yacht anchor it's barely usable. I also had a 260 in the '77 Cutlass S 4-door I drove for about a year ('78 - '79). No power, bad gas mileage, really the worst of both worlds. Worst. Engine. Ever. End Of Story.

 

Thanks but I have a oldsmobile brochure for 1979 an it says the engine size 4.3/260/V8, 5.0/305/V8 it's not a 307. That being said the there has been confusion over size. I sorry I only was referring to the normal Joe blow calling them small blocks

 

The 305 is a Chevy engine, not an Olds engine.

In 1979, GM mixed and matched engines among divisions.

Parts will not interchange between Olds and Chevy engines, but most parts will interchange between most Olds engines, and especially among each of the engine subsets of small and big blocks, with the exception of the 260, which has almost no parts that interchange with other Olds engines, even though it is essentially the same block.

- Eric

 

Do see what confusion there is! When I sold them we called them 5 liter or 5.7 liter. Now when I order my intake I was thinking I was getting an intake to upgrade an replace my old intake that was corroding away. I only wish I would ask first here before I got the 2711 Elderbrock intake . I thank you for your knowledge an this forum. I'm glad to be a part of it. We drive Oldsmobiles because of there great cars that our fathers drove!

 

Yes the edelbrock intake will bolt up ,but the ports as mentioned will be a mismatch.Imo as i have no facts to back it, the 260 was GMs way of meeting the feds emission requirements and keeping the current at the time v8 engine.Nick

 

The 260 was a way of getting straight-six power and economy (they hoped) with V-8 smoothness. (The 250 straight six was originally rated at 150hp, while the 260 was rated at 110hp).

- Eric

 

Your an idiot.
:-)

Lame search here for "intake thread" [with quote marks] brings up
https://classicoldsmobile.com/forums...=intake+thread

Also, there was a Chevy "307" V8 offered in the late 60's or early 70's, maybe in the Nova? I remember seeing that fender emblem in a boneyard long ago...

 

What size carb is the 8101? Please report back on how it runs. Guys have used the discontinued SP2P and the can't give it away A5 aluminum swirl port 307 intake with some port matching on the 260. Low compression, weany ports, tiny cam and cubic inches make even Olds fans dislike the 260. Good part is it doesn't make enough power to hurt itself. That 2711 intake manifold has good resale value when you go BBO. Don't discount the Olds 350 or 403 as potential power plants, both can perform very well and are a direct bolt in. The 455 can have clearance issues with the A/C box and needs the A/C bracket modified to work properly.

 

I resemble that remark!


Okay, so it's called "Oldsmobile Intake Thread."

Got it. You'd think search would have turned that up with settings to look for "Intake" in the title.

Here are the A1 and A2 260 manifolds from the top.
I still don't have any bloody pictures of this intake's ports.

_A1-916_260_INTAKE_zps1b0d6ecd.jpg

_A2-085_260_INTAKE_zps9a7563c0.jpg



Yes, the 307 was made in the late '60s to early '70s ('68 to '73, I think), had a bore and stroke of 3.875" x 3.25", and was rated at 200hp / 300 ft/lbs.
We've got one sitting in a corner of the barn, that we pulled out of a Nova years ago.

For comparison, the 305 was made from '76 to '92, had a bore and stroke of 3.746" x 3.48", with a rating of about 130hp.

Remember that Chebby also made a 262, 265, and 267 V8, so there've been lots of tiny GM V8s over the years.
Of course, F_rd has GM beat with the 136ci 36hp V8 and the 221 and 225ci 85hp and 125hp V8s.

- Eric

 

Well I drove it home today an it is find. The 260 is just what it is a small V8 with no real horse power . It came with this car an is just a nice smooth cruiser for now . I but my 15" sport wheels with B F Goodrich TA . It looks bad but I will be looking later on this summer up grading to a nice 350 an then I will be finished. BTW it was 2 mm not cm difference in the ports . Thanks again for all input ! Oh by the way does anyone know where I can get a oldsmobile hat?

 

Try here: http://www.ebay.com/sch/i.html?_trks...at=0&_from=R40

or here:

http://www.amazon.com/s/ref=nb_sb_no...dsmobile%20hat

for starters.

Will also be a lot of them for sale at the Oldsmobile Homecoming in Lansing, MI on June 14th .

 

So, how's the 260 running, and are you SURE it's a 260 and not a 307?

- Eric

 

It is what it is .....260 4.3 liter. It runs fine no real power but smooth V8 Olds. It's fine for now but will put a 350 later this fall . I have tried to down load my photos but only been able to do only one at a time. How do U like my wheels?

 

Nice wheels.

Shame your mechanic didn't take any pictures of the surprising difference in size between the intake and the head ports. I've searched for photos, myself, and haven't found any.
I just remembered there was a guy in the Netherlands a year or two ago who took one apart and photographed it, but I just tried and couldn't find the thread.

If you're happy with it, that's all that matters.

- Eric

 

Where this post is 100% correct, the use of the word "Performance" when talking about a 260. Yeah that made me LOL

A major benifit to the 260 is, it's an Olds engine and will be an easy swap for any Olds block into that car

 

It is rare that Joe ever posts anything that doesn't make sense. And his last post is no exception.
However, In regards to intake/head port mismatch on a sbo 260, I must say it does defy the odds.
1977 Cutlass.
Using a 350 intake on a 260 with a q jet from a 307. Big mismatch but the car made noticeably more power than it did with the 2bbl dual jet.
I don't recall which intake gasket was used though, it was twenty years ago.
Mileage and driveability never changed. We actually expected to have negative effects in power delivery, but they never manifested.
That setup is still going strong today. No doubt the vortex type flow characteristics would show up at higher engine speeds as lost power..... but its a 260 that doesn't make any thing but noise past 4800.

 

So, this sums up as "go ahead and use whatever intake, the port mismatch will not be an issue."

Right?

I'd still think the puny-port A5 4-bbl intake would be the BEST available choice.

I guess y'all are going to make me go out and take photos of the PORTS of all the intakes now?

 

Bottom line...don't bother doing anything to the 260....you can put on 330 heads, I guess, but it's still gonna be a turd....

 

You know we love photos, Chris!

- Eric

 

 

[QUOTE=Octania;686528]So, this sums up as "go ahead and use whatever intake, the port mismatch will not be an issue."

Right?


I was simply passing on a known combination that gave improved overall performance. The small port(307) type intake may give better performance, but again its a small valve engine so use whats available to you.
The 260 was built for efficiency much like the Pontiac. Calling it a pos is like calling the 455 a gas guzzling boat anchor. The 455 was built for torque and power, different animal.