Wait. 25 mpg in an FJ40?
Offenhauser intake manifold on the 2f engine, (1 Viewer)
- Thread starter Landcruiserfj45
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I bought the Man-A-Fre combo #2 back in the day, and as I recall I got from 9 to 12 mpg. I can't really tell you if there was much of a difference from stock in mpg or performance. Of course that was forty six years ago.
- Thread starter
- #23
Hi,
very cool think.
But did it really produce 50 hp ?
That would have easily been 185 hp.
You must have clearly felt that...
- Thread starter
- #24
OK...i just see it was 46 years ago,a really long time...i was just 5 years old.
But if it really produced 50 hp,as described,it was definitely a very cool thing...
But if it really produced 50 hp,as described,it was definitely a very cool thing...
The only thing I clearly felt was the additional and excessive floorboard heat from the header.Hi,
very cool think.
But did it really produce 50 hp ?
That would have easily been 185 hp.
You must have clearly felt that...
- Thread starter
- #26
Hi guys,
a friend tell me that there use to be a conversion kit to a double carburetor system for the old f engines.
I've asked Google a little bit about this, but haven't found anythink about it yet.
Do any of you know something about it and maybe even have some information or even photos ?
I'm a little curious and would really like to find out more about it just out of interest...
Have a nice Sunday...
a friend tell me that there use to be a conversion kit to a double carburetor system for the old f engines.
I've asked Google a little bit about this, but haven't found anythink about it yet.
Do any of you know something about it and maybe even have some information or even photos ?
I'm a little curious and would really like to find out more about it just out of interest...
Have a nice Sunday...
Hi guys,
a friend tell me that there use to be a conversion kit to a double carburetor system for the old f engines.
I've asked Google a little bit about this, but haven't found anythink about it yet.
Do any of you know something about it and maybe even have some information or even photos ?
I'm a little curious and would really like to find out more about it just out of interest...
Have a nice Sunday...
Here is a link.
This would be the aftermarket intake manifold you were talking about. It was a limited production done by Man-A-Fre in the late 1960's and would be one of the first products produced for Land Cruisers by Man-A-Fre before the company transitioned from Carburetor Adapter Plates to Land Cruiser Parts. There is an original Man-A-Fre worker that is located in Nebraska that still rebuilds the old Man-A-Fre Carburetor Adapter Plates. This intake would have ran dual Rochestor 2G 2-Barrel Carburetors.
middlecalf
SILVER Star
Wow, didn’t know there was a Man-A-Fre dual carb setup for F135s.
Here’s the Offenhauser dual carb setup.
I know nothing
Here’s the Offenhauser dual carb setup.
I know nothing
Green Bean
SILVER Star
Somehow the term "speed kit" doesn't seem to go with the Toyota 40 Series Land Cruiser which have the aerodynamics of a concrete block. But I freely admit I have not complete my exhaustive research... Perhaps one of these trucks was the pace car at Indy. 
JohnnyC
Long ago TLCA# 2231
middlecalf
SILVER Star
The most important information about a dual carb setup is illustrated in the Offenhauser article’s first picture of Carl Offenhauser standing next to a motor tester: i.e. both elements are necessary to make the dual carb setup truly a functional improvement over stock.
Even though there’s this in one of our barns…
…I still know nothing.
While Carl’s ‘64 motor with 18k miles might like what’s been done to it, my ‘64 motor with a lot more miles has yet to realize that more fuel to the fire is not necessary nor necessarily better. Kind of like a teenager who thinks more money will be the answer to their problems.
Even though there’s this in one of our barns…
…I still know nothing.
While Carl’s ‘64 motor with 18k miles might like what’s been done to it, my ‘64 motor with a lot more miles has yet to realize that more fuel to the fire is not necessary nor necessarily better. Kind of like a teenager who thinks more money will be the answer to their problems.
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They aren't really speed equipment.Somehow the term "speed kit" doesn't seem to go with the Toyota 40 Series Land Cruiser which have the aerodynamics of a concrete block. But I freely admit I have not complete my exhaustive research... Perhaps one of these trucks was the pace car at Indy.
Speed equipment is built in a machine shop, not bought in a catalog.
These are dress up kits.
People still to this day put dress up kits on their cars. Usually they run worse afterwards, and often they won't pass a smog with the kit. In my experience as a mechanic I've never seen an instance where someone replaced a single carb with dual carbs and had it run better.
Dual carbs make the same air travel through a wider set of holes which reduces its velocity and it's ability to fill the cylinders completely at low RPM.
F engines don't run at high Rpm due to their stroke, so you need to concern yourself with low RPM power.
Low rpm power is what gets you crawled safely out of obstacles. Low RPM power is the landcruisers strength.
Let's recap:
No dress up kit in the world is going to make the F into a high rpm engine.
More carburetor decreases air velocity at low RPM.
If you're trying to 4wheel the thing, I'd hang the fancy intake on the wall, run stock.
If you just drive around town and to car shows, put the dress up kit on it and show off.
middlecalf
SILVER Star
^ yup!
And my hardheadedness keeps trying to tell my out-of-shape fat cylinders to get off the couch, get pumping and that they need more CFM, but they just ignore me. “Here you go slouches, eat more air and fuel. Take that!”
And my hardheadedness keeps trying to tell my out-of-shape fat cylinders to get off the couch, get pumping and that they need more CFM, but they just ignore me. “Here you go slouches, eat more air and fuel. Take that!”
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Good that you read not to install a Weber 38/38. Not because it is a bad carb, I’ve ran them for over a decade and not once have I had a single issue. That said, the 32/36 AND 38/38 were made for engines no bigger than 2.3 liters. The accelerator pump shot is not sufficient for an engine bigger than 2.3l, and a lean sag will be experienced that can not be tuned out. This is why many claim that Webers like lots of advance, which is hog wash. The extra advance is helping a very lean air/fuel mix to better combust, that is all. Also, most end up jetting the idle circuit pig rich to compensate as well.
A 4 barrel is not too much carb for the 2F. The primary’s on a 4 barrel are smaller than a Weber 38/38 and Holley 350, and the secondaries will only open when a restriction is present. At least, if you are running vacuum secondaries. CFM calculators should be thrown out the window when sizing a carb for a straight six. The intake stroke pulses the carb, this can be seen when running multiple carbs where each throat feeds it’s own cylinder. The 2F requires 700 cc’s to be filled per intake stroke, a Chevy 350 requires 712. At any given rpm it takes the same amount of time and volume to fill the 4.2 l6 as it does the 5.7 v8. Therefore if a v8 of similar cylinder volume requires or runs best with a 600-650 cfm carb, the same can be said for the l6.
This has been shown with 650-750 cfm carbs on Ford 300s and also Chevy 292s. If using an “average” cfm calculator on a straight six, your cfm will show you need a much smaller carb and will become a restriction to the engine.
All that said, if no change is made to the cylinder head and exhaust, and the restriction occurs elsewhere, any benefit from the larger carb will be greatly reduced.
Anyway, I do believe Offy will still make the C series manifold upon demand. They are listed on Summit Racing, and have a ship date so…….
Lastly, the C series specifically states to run a 500+ cfm carb. The DP states 500cfm or less.
A 4 barrel is not too much carb for the 2F. The primary’s on a 4 barrel are smaller than a Weber 38/38 and Holley 350, and the secondaries will only open when a restriction is present. At least, if you are running vacuum secondaries. CFM calculators should be thrown out the window when sizing a carb for a straight six. The intake stroke pulses the carb, this can be seen when running multiple carbs where each throat feeds it’s own cylinder. The 2F requires 700 cc’s to be filled per intake stroke, a Chevy 350 requires 712. At any given rpm it takes the same amount of time and volume to fill the 4.2 l6 as it does the 5.7 v8. Therefore if a v8 of similar cylinder volume requires or runs best with a 600-650 cfm carb, the same can be said for the l6.
This has been shown with 650-750 cfm carbs on Ford 300s and also Chevy 292s. If using an “average” cfm calculator on a straight six, your cfm will show you need a much smaller carb and will become a restriction to the engine.
All that said, if no change is made to the cylinder head and exhaust, and the restriction occurs elsewhere, any benefit from the larger carb will be greatly reduced.
Anyway, I do believe Offy will still make the C series manifold upon demand. They are listed on Summit Racing, and have a ship date so…….
Lastly, the C series specifically states to run a 500+ cfm carb. The DP states 500cfm or less.
I should be picking mine up from the shop this week - ended up pulling the offy manifold and Holley 350 and taking it back stock (well, with headers staying put). Very interested to see how she runs in comparison (and maybe listing for sale the old set-up here soon).
Too bad you didn’t put a proper 4 barrel on the Offy. I may be picking up a C Series and slapping a QuickFuel Slayer 600 on her. Fully adjustable idle feed restrictors, air bleeds, secondary jets and accelerator pump. Oh and, a simplistic screw adjustable vacuum secondary
If you decide to sell the Offy please let me know.
Interesting…..I’m just one of those backwards thinking types that thinks most anything changed out on a Toyota that doesn’t also say Toyota isn’t really an upgrade. Talking out of both sides of my mouth, though, as I am keeping the headers.Too bad you didn’t put a proper 4 barrel on the Offy. I may be picking up a C Series and slapping a QuickFuel Slayer 600 on her. Fully adjustable idle feed restrictors, air bleeds, secondary jets and accelerator pump. Oh and, a simplistic screw adjustable vacuum secondary
If you decide to sell the Offy please let me know.
I think Toyota did/does a lot of things right but there are things they could have done/did better.
I wouldn’t say backwards, in many cases stock is rock. However, running Yukon gears, Grizzly lockers, and RCV axles will greatly exceed off road performance and strength far beyond what Toyota originally built.
I also run GM HEI with a Toyota electronic dizzy, as IMHO, it is the highest performing most reliable setup I can achieve. Not to mention replacement parts are dirt cheap.
I have no loyalty to Toyota brand, instead like to take the best of all things available to me. Interestingly, our straight six motors were based off of GM Stovebolt engines
Regardless, I changed carbs because I could not manage to find jets for the darn thing. Looked everywhere, all I found were rebuild kits. I’m at 9000 feet and have big elevation changes to deal with, so I went with something that was far simpler to tune, to obtain jets for, etc.
