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Deloreandude83

Replacement Engine

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Deloreandude83

Hello all, as you may remember I restored a 67 Broadmoor last year. Since then I have been having engine trouble with it despite the rebuild. And with as much time and money invested in it getting it to look and perform the way it does now, its a bit aggravating not to be able to use it to its potential. So I am wondering what new engines, preferable auto start, that would easily fit in place of the original 7HP with little to no modification, Thanks!

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goatfarmer

Beautiful tractor!dOd

What kind of engine problems are you experiencing? AFAIK, most any vertical shaft Briggs should fit. Lots of Craftsman's, MTD's, etc, on Craigslist for little money that are potential engine doaners.

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SmilinSam

I think you are pretty much stuck with using the old L head 7, 8 and 10 hp blocks... if you can find one, or a good used one in something else. That is for a pretty much trouble free drop in fit anyhow.

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Deloreandude83
quote:Originally posted by goatfarmer

Beautiful tractor!dOdWhat kind of engine problems are you experiencing? AFAIK, most any vertical shaft Briggs should fit. Lots of Craftsman's, MTD's, etc, on Craigslist for little money that are potential engine doaners.


id="quote">
id="quote">Thank you! and there are a couple issues I'm having with it, mostly that it smokes like a freight train, despite new, oringinal and over-sized rings. And secondly, the original up-draft carb was badly damaged from being outside with no cover or air filter for many years and have since replaced it with a 12HP briggs carb, which works, but not properly. Also with the carb being uncovered for all that time, the intake valve was slightly open, and as you may have guessed, a fair bit of water has been on the top side. I was able to clean up that area though to look really good, but there's really no telling how bad the damage actually was.166yal5.jpgx1gcr7.jpg

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Chris727

I think the updraft carb is similar to the ones used on the model 19 and 23 engines. They are fairly easy to find. If you still have your original linkage and governor linkage you should be able to get the correct carburetor on it again. As for the internals of the engine, I hope the pictures posted were from prior to the rebuild. The intake valve looked bad enough that it should be replaced. You can probably find a new short block for that engine. Sometimes they can be had for under $150. The trouble with going to a new type of engine is that most are overhead valve and will not fit properly. The shrouds are plastic and would destroy the cool factor of your restoration. A 10 or 11 hp will not fit behind the grill.

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SmilinSam

Chris, I was always told the 8 and 10hp blocks were the same while the 11 and 12 hp blocks were the same size but bigger than the 8-10???

I may have been told in error though.?.

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Chris727

I know I have swapped 7's and 8's in the Broadmoor's as well as the sheet metal from a 7 to an 8. Seen lots of Broadmoors repowered to 8hp with the original S/G swapped over to them. I had a couple of tens and elevens. I sold them but from what I recall they were about the same physical size.

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Deloreandude83
quote:Originally posted by Chris727

I think the updraft carb is similar to the ones used on the model 19 and 23 engines. They are fairly easy to find. If you still have your original linkage and governor linkage you should be able to get the correct carburetor on it again. As for the internals of the engine, I hope the pictures posted were from prior to the rebuild. The intake valve looked bad enough that it should be replaced. You can probably find a new short block for that engine. Sometimes they can be had for under $150. The trouble with going to a new type of engine is that most are overhead valve and will not fit properly. The shrouds are plastic and would destroy the cool factor of your restoration. A 10 or 11 hp will not fit behind the grill.


id="quote">
id="quote">Yes these pics are pre-rebuild, I don't believe I have any post-rebuild pics.

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Deloreandude83
quote:Originally posted by RayS

Was the motor tolerances checked with micrometers and proper measuring tools to see if it was within spec. Before reringing it?


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id="quote">We did not check the specs before up-sizing the rings. However, we did try honing out the cylinder walls but the final product was always rough, as if the metal was deteriorated and just finely breaking off rather than being cleanly shaven down

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Chris727

I believe a special hone is required for honing an aluminum bore. Take the block to a machinist and they can determine if it can be saved. Oversized pistons and rings for the 7-8hp engines are easily and inexpensively found as NOS on eBay.

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