Crossflow in an early Bronco?

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hucklburry
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Crossflow in an early Bronco?

Post #1 by hucklburry » Sat Aug 20, 2016 1:08 pm

I have been searching, has anyone actually installed an aussie block with crossflow head in an Early Bronco?

I am heading that direction, and don't see where it has been done. I am not scared, just wondering, particularly about the exhaust, do the "extractor" headers fit ok or use the manifold??

The rest of my research makes me believe it will work well, with an unknown on the oil pan still.

--Jim

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rocklord
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Re: Crossflow in an early Bronco?

Post #2 by rocklord » Sat Aug 20, 2016 2:26 pm

They did make Crossflows with rear sumps.

viewtopic.php?f=3&t=65422
Dan

Currently Own
1965 Mustang, 200CID, 3Spd
1964 Corvair Coupe, 164CID, 140HP, 4Spd
1961 Corvair Lakewood wagon, 145CID, 80HP, 2Spd Powerglide Auto.
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hucklburry
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Re: Crossflow in an early Bronco?

Post #3 by hucklburry » Sat Aug 20, 2016 4:02 pm

I will keep that in mind, thank you. This bronco is a grocery getter, not a wheeler, so it doesn't need the articulation that would drive the front axle up that far, I don't think. Its something I will have to see once its mocked up and decide from there, its nice to have options!

jimmyv65
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Re: Crossflow in an early Bronco?

Post #4 by jimmyv65 » Fri Aug 26, 2016 9:53 am

Huck,

You may want to consider the 300. There is a ton of mis-information about the 250 vs. the 300. The 300 weighs the same and is only 1 inch longer. It would take some fab work on the motor mounts and maybe an adjustment to the radiator mounts to bump that slightly forward.

The 250 with a crossflow head gets very expensive quick. The 300 is a very inexpensive motor. It has tons more options for intakes, headers, etc, etc. It would be less expensive. Parts are easier to find. Much better situation for carb and/or efi.

I went with the 250. Hindsight, I should have done the 300. I am all in on the 250 at this point.
1966 Bronco-'78 250-Meagsquirted TBI, DUI, Header, Cam, Hydroboost & Front Disc, Uncut, 1" body lift, 2.0" suspension lift

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rocklord
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Re: Crossflow in an early Bronco?

Post #5 by rocklord » Fri Aug 26, 2016 1:46 pm

jimmyv65 wrote:Huck,


The 250 with a crossflow head gets very expensive quick. The 300 is a very inexpensive motor. It has tons more options for intakes, headers, etc, etc. It would be less expensive. Parts are easier to find. Much better situation for carb and/or efi.

I went with the 250. Hindsight, I should have done the 300. I am all in on the 250 at this point.


The engine hucklburry is looking at is an actual Australian 250 Crossflow, block and all.
Granted, almost everything has to come from Australia, but there is a lot of "go fast" parts for the Crossflow.
Intakes - you can get ones to fit 2Bbl, 4Bbl, or triple weber carbs; there is also a stock EFI intake that looks similar to the 300 one.
Headers - you can get long tube, shortie, or duals.
Cams - you can get hydraulic, solid, or full roller from mild to wild.
They also make double chain cam gears (no need to machine a 302 set to work), and deep sump oil pans.

Australia didn't abandon the 250 inline six in the late 70's like the US did, they improved on it and kept it in production until this year (2016) where it now displaces 4.0L, sports dual overhead cams, and is rated over 250HP.

Don't get me wrong, the 300 is a great engine that will last forever, but the 4.1L Crossflow has a lot going for it too.
Dan

Currently Own
1965 Mustang, 200CID, 3Spd
1964 Corvair Coupe, 164CID, 140HP, 4Spd
1961 Corvair Lakewood wagon, 145CID, 80HP, 2Spd Powerglide Auto.
2017 BMW X3, 3.0L Dual Turbo, 300HP, 8-Spd Auto

hucklburry
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Re: Crossflow in an early Bronco?

Post #6 by hucklburry » Sun Aug 28, 2016 7:35 am

Thanks Dan, didn't hit any rain, she is safely tucked into the garage that I need to finish re-arranging before I start pulling engines.

Regarding the 300, I have a friend putting one in. I haven't researched them, but my friend was notching the front frame crossmember under the engine for it to fit. I don't know if that is required, but not for me. The 300 weighs between 100# and 160# more than this aluminum headed aussie 250. The dimensions on this aussie 250 block are almost a drop in like a 200, the block is narrower at the engine mounts than the US250 and the head is shorter making it not as tall as a US250. I don't have to change the Bronco to drop it in except maybe the clutch linkage. If I blew this motor up, I could get a US250 or a 200 and drop it in with bellhousing and keep on driving. I liked that.

The weight is less than a US250, especially with the aluminum head, and since this is a grocery getting street truck with no power steering, I like the weight advantage. The 300 weighs more than a 302, at least short block to short block.

Here are some spec's to think about:

Original 170 engine 105 gross hp, probably 80hp net, 158ft lbs
300 engine, one of the higher rated ones 150hp 260ftlbs
US250, later with large log 99hp 184ftlbs (pre72 were 240ft lbs)

Aussie 250 crossflow standard specs aluminum head 130hp 233ftlbs

This one has a bit of a cam, for torque, and a header, so maybe 140-150hp and torque ??? If I spent the money on a 4 barrel,(about $400 for intake plus a carb) I'd make gains again but I want to see this one running (and swap to duraspark after that) and see the gas mileage. I think it will be a fine combo all the way around and close to stock 300 specs in a lighter/easier to install package.

I don't see the effort and weight of the 300 being worth it for the performance difference. Not knocking the 300, just not the way I wanted to go for this bronco. Its lifted and cut on 31s, but otherwise is a complete 66. My goal is it looks exactly like it does now, column shift little 66, unless you pop the hood, then it doesn't quite look original anymore (I put on disc brakes and dual master cylinder, now this engine going in).

hucklburry
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Re: Crossflow in an early Bronco?

Post #7 by hucklburry » Sun Aug 28, 2016 8:26 am

OH, and regarding fuel inject, there are multiple ways to do it, but with the fitech and other stand alone systems out nowadays, its all pretty easy.

For my 69 Bronco, I stayed with Ford fuel injection on a small block V8 for ease of parts availability and it works well, but if you want to inject something, its all pretty available for whatever you want. I bet some people even go Fitech on a 300.

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