200, 250, or 300 i6?

AC932 · Nov 4, 2019

I can't speak for I6's, but fuel economy-wise, I don't think the stock V8 is really that bad. I get ~16 MPG in the summer, closer to 15 in winter, and if I'm really trying, about 20 is doable (that's all highway driving, more city/stop and go gets me about 12-13). Besides, I really like the way it feels to drive ;D

http://www.fuelly.com/car/ford/bronco/1974/ac932/774940

If you really want a 6, just shove one in there, worst case you end up ripping it out and doing something else, these things are never done anyway.

bmbm · Nov 4, 2019

250 or 300

I could see the 302 as being good for a way easier swap than a 300-with a nv3550. Plus they are easy to find. The od trans is a great improvement for all around driving. It is likely that most 250's you might find would need a rebuild.
I previously ran a late model big log 200 with points ignition and stock 3spd trans and it would not pull the grade going up to Tahoe in third. Had to go to second. With a stock used low mileage 250 with a fresh valve job and DSII ignition and NV3550 I easily got to 65 in fourth on the same grade. I backed off simply because of the noise. Bare metal floors in the Bronco that day.
The 250 does have the sbf bell pattern so any trans ok. The later 200 has the large bell which can be machined for more trans choices.
I never feel underpowered on the freeway or off road.
I also have 4:11 gears as mentioned and 30" tires as mentioned.

Aariley5 · Nov 4, 2019

Thank you bmbm that is exactly the kind of information I’m looking for as far as comparison between the i6’s.

I have considered the 302 as an easier swap, even just taking an explorer efi motor and tossing it in. My brother has built a couple broncos with that setup and its proven to work well and be fairly efficient and easy. But I am much more interested in the inline 6 swaps. They’re different, not so common and I feel, better suited for me.

blubuckaroo · Nov 5, 2019

The 144/170/200/250 inline six family of engines are a different family that the 240/300. The 240/300 have a reputation for great torque and very acceptable fuel mileage.

The big issue is the short engine bay of a Bronco. I would expect it to need modifications to the firewall, radiator support and front cross member.
I've only seen this mod done a few times, but with great results.

My Brother's '78 F150 4X4 has a 300 and it's way better than a 302 or even a 351W for that truck. It's a pretty rough truck, but runs really strong. He calls it his snowmobile.

markw · Nov 5, 2019

Vintage Inlines has a new alloy cylinder head apparently. Supposed to have been released by now. Looks very interesting. Provisions for direct port injection. They're at SEMA this week, I hope to get some information on it if I can get someone to stop by their booth.

CraigS · Nov 5, 2019

VI had their head out and sold them all last I knew. They are taking orders for the next batch. I see that their website says they will take more orders after SEMA.
I have the Oz 2V head.

vintageinlines.com

markw · Nov 5, 2019

How does that run? Those are pretty rare pieces.

CraigS · Nov 5, 2019

Runs great on the engine stand. Not in the Bronco yet. Carb is the biggest issue, so I hope to go for the Sniper 2bbl when installed.
They seem more rare now then when I got mine quite a few years ago. Bought it for $800 completely rebuilt - can't touch them for that now, if you can find one. Might spring for an aluminum head one day.

markw · Nov 5, 2019

In my dreams I think a direct injected 250 would be the thing. Not sure how to go about it yet but it will likely involve EFIGUY when it gets to that point. Why keep it simple?

Aariley5 · Nov 5, 2019

Blubuckaroo: His snowmobile &#55357;&#56834; I like that! Since I’m in Colorado and I like to play in the snow I think thats most likely the route I’m gonna end up going, the 300. The 250 sounds great and maybe easier but it seems like parts may be easier to get for the 300s. Also if the 300 takes a little more shoehorning, I don’t mind. A little extra work at the beginning I think will make for a lot better outcome in the long run.

Im hoping maybe some guys with 300s might see this and chime in, I know theres at least a few out there.

Pa PITT · Nov 5, 2019

I wrote for about 30 minutes last night . & When I went to post it .. I guess I hit the wrong button & erased it all. Maybe my Net went down or something .
It makes me so mad when I do this . I can't rewrite it.

sykanr0ng · Nov 5, 2019

Pa PITT said:
I wrote for about 30 minutes last night . & When I went to post it .. I guess I hit the wrong button & erased it all. Maybe my Net went down or something .
It makes me so mad when I do this . I can't rewrite it.

If it happens to you more than once make a new habit to write the comments out in something like Notepad (a simple text editor for your computer) then copy and paste to post. If it posts you can delete from Notepad, if it doesn't you can try again without writing it all over.

bmbm · Nov 6, 2019

300 install info

Then you might be interested in this:

https://fordsix.com/viewtopic.php?f=36&t=78285

Hope this works just paste into your browser and see.

Aariley5 · Nov 6, 2019

bmbm said:
Then you might be interested in this:

https://fordsix.com/viewtopic.php?f=36&t=78285

Hope this works just paste into your browser and see.

I have read through that one and probably every other related thread on here and fordsix and a couple other sites.. I keep trying to think of different related terms I can use to search with to dig up old lost threads. So far the amount of information you and the other guys have put out there about the inlines really is helping a lot in my decision making on this.

bmc69 · Nov 7, 2019

This '69 with a '78 250 engine was my daily driver for several years. Got almost 15 mpg on the highway if I stayed at 55 or less.

Uses the 302/351w belhousing. Taller than the 170/200 too...was an issue for air cleaner clearance since I had no body lift.

bmbm · Nov 8, 2019

SROD attached to a 300 in Kansas

SROD attached to a 300 in Kansas City, MO. Might work out for you.

https://fordsix.com/viewtopic.php?f=45&t=80494&p=624886#p624886

Bajabrewer · Nov 8, 2019

I'm doing a 250/5 speed in my 66. I'm hoping for a reliable driver that won't break the bank to build. I have cam questions but I'll start my own thread on that so I don't hijack this one.

Aariley5 · Nov 9, 2019

Bajabrewer said:
I'm doing a 250/5 speed in my 66. I'm hoping for a reliable driver that won't break the bank to build. I have cam questions but I'll start my own thread on that so I don't hijack this one.

I’d like to follow along with that thread can you post a link here once you start on it?

Bajabrewer · Nov 10, 2019

Here's what I posted looking for advice on cams.

https://classicbroncos.com/forums/showthread.php?t=298743

Relicsrule · Nov 11, 2019

I6

I have a 200 six in my 68. Its been balanced has a mild cam classic inline alum head full roller rockers (tera yellow) holly 390 cfm carb. running on the high way at 60 it gets 17 mpg. When you step into it really moves out.That said it is not about mpg as I could of built a v8 for half the money and used the savings for years of gas. most people like it because it is different. Dave

200, 250, or 300 i6?

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