20hp to 29hp engine swap in progress

[Rock Doctor]

I've been talking to this guy for a bit (nice guy), and he has decided to post vids of his engine swap as he goes
This is his second vid (I have not seen it yet, damn Dial-up), his first vid detailed the mods he had to make for his alternator bracket.

Vid 1

Vid 2

Vid 3

Vid 4

Vid 5

Vid 6

Vid 7

Vid 8

OOPS, missed this one
Vid 8.5 ;-)

Vid 9

I'm still waiting on quotes for the 27hp Carbed option, and really don't know which route I'm going to go with. The 29 DFI is tempting, but the 27 Carbed is probably easier to diagnose/work on if I have problems in a remote location

RD

[Roger S]

That's great to have someone do it first. Looks like a lot of work. I'd want to do a lot of measuring with the old engine in there. That's one thing I was very grateful on my response engine, just take it out, modify, and re install. The large displacement of the 27 or 29 should have lots of low rpm torque for the way you load the conquest.

[mike bar]

I think your friend should give himself a little credit there. He did a great job. I see where his concerns are going with this section of vid. and I'm sure he's prob. thought of this but I'm going to ask anyways,Is the center of the shaft from the base on the old engine the same height as the new one. If not, the center from clutch to clutch will change slightly. Again,it's not my intention here to insult anyones intelligence here. It's just my way to be always thinking cautiously.
Mike

[Rock Doctor]

I think your friend should give himself a little credit there. He did a great job. I see where his concerns are going with this section of vid. and I'm sure he's prob. thought of this but I'm going to ask anyways,Is the center of the shaft from the base on the old engine the same height as the new one. If not, the center from clutch to clutch will change slightly. Again,it's not my intention here to insult anyones intelligence here. It's just my way to be always thinking cautiously.
Mike

Yes that has come up, it's .3" higher on the new engine.

[Rock Doctor]

I've added VID 5 above .

[Rock Doctor]

Added Vid 6 above ^

[mike bar]

I like this guy's humour, he cracks me up Great Job RD

[Rock Doctor]

I like this guy's humour, he cracks me up Great Job RD

Yes, he seems like quite a comedian, hope to meet him some day :-)


RD

[Rock Doctor]

added vids 7 and 8 ^

[JohnF]

For the curious:
FD620D specs (pdf)
FD750D specs (pdf)
FD791D specs (pdf)

From the pics it looks to me that a person could choose an aircleaner much shorter than the one shown in the vids above - enough to not be a concern.

... Is the center of the shaft from the base on the old engine the same height as the new one. If not, the center from clutch to clutch will change slightly. ...

I know that I do not have enough information to determine this. (Mike may.) If we assume that the line through the shaft centers is parallel to the surface of the bottom of the engine then it is true. If, for example, the engine shaft of the FD620D is half the delta below the parallel line then the shaft to shaft distance remains the same post swap. If the engine shaft is further below than that, then the shaft to shaft distance actually decreases.

Does anyone know the the distance center-to-center of the shafts and whether the shafts are parallel to the engine bottom? We might be able to make up the difference in how you drill out the engine mount holes.

[Roger S]

I don't think the crank height difference is enough to engineer for. If the engine mount holes are the same, only needing enlarged, I would use a drill with a pilot OD spun on the tip. I think you can change the shim pack on the trans clutch to adjust the belt if needed.

I don't think I've seen an engine where the crank wasn't parallel to the block mountings.

Great thread by the way, a labor of love, Sure makes me appreciate the simplicity and spaciousness of an air cooled briggs vanguard. But the big water cooled kawasaki will be torquey and quiet with power to spare.

[JohnF]

I don't think the crank height difference is enough to engineer for. ...

Not gonna disagree - but I did geek out and do the calculations. (I hadta know... )
So, assuming that the shafts began on a plane parallel to the engine mount surface. (oh, and the actual height change is 0.33 inches)
At 4 inches original distance the delta is 0.013589 inches.
At 8 inches original distance the delta is 0.006803 inches.
At 12 inches original distance the delta is 0.004537 inches.
(remember, I have no idea how far apart the shafts are but I imagine I have bracketed that dimension.)

If we assume normal fit holes the M8 of the FD620D will be 11/32 inches. The M10 needs 13/32. That means we can move the hole 1/32 (0.03125) inches.
It works! Just gotta be real steady with hand drill...

I don't think I've seen an engine where the crank wasn't parallel to the block mountings.

Hmm, I mean the plane through the shaft ceterlines parallel to the plane of the engine mount surface. I was visualizing the shaft plane as a line through the centers at the shaft ends and assuming the shafts themselves are parallel to each other and that each is parallel to the engine mounting plane.

[Rock Doctor]

Glad to see this is drumming up some discussions
With any luck my new engine should be here within a week or two, it's great to have some of the figures worked out beforehand.

I've added another vid to the original post up above


RD

From the pics it looks to me that a person could choose an aircleaner much shorter than the one shown in the vids above - enough to not be a concern.

.

What he has is the "Heavy Duty Canister Filter", The other option is the "Standard Filter" witch looks very similar to the stock 20hp air filter. I actually don't know for sure, but I think the engine I have ordered is coming with the Standard Filter assembly.


RD

Hey Mike (Admin)
Why do some of the vids show up as "vids", and others show up as "Links"?
Am I doing something different?

RD

Oh ya, I missed a vid, and added it as "vid 8.5" in the original post.

[Mike]

Hey Mike (Admin)
Why do some of the vids show up as "vids", and others show up as "Links"?
Am I doing something different?

One of your links included some extra code. Something like "&playnext=" You have to stop the link at the video's address (the part before the & symbol) Once you include that extra code it screws up the entire embedding process in that particular post for good. It's just a finicky thing. If that ever happens to you again there is a "insert video" tag when you edit or reply to a post that will fix the link for you. Just click on it (the filmstrip) and paste your link. Hit OK. Just like when you link to a picture somewhere else. You can do that everytime and it will make sure the video embeds properly or you can take your chances with the site embedding it automatically.

Kinda a long explanation but it's not as convoluted as it sounds.

[JohnF]

Been away for awhile. Came back and found the post where this upgrade is done. I spent some time with my machine, super-tracked, in the mountains this winter. I Ice fish around 2Kft in SD, hunt on family property at around 4Kft in NE, live at around 6Kft, and played in the snow climbing from 9Kft. I had no trouble at all with snow but uphill turns at >9Kft are a drag.

I do think that at a minumum I will get some sort of adjustable jetting. I am pretty quick at pulling the carb and rejetting but...

I think I want the FD791D-DFI we mentioned here but RD's upgrade and the simplicity of the swap are very compelling. FD750D right? Which model #? Any advice? (Yeah, I've seen the other thread with the video but stopped here because it also includes the FD791D...)

[EDIT] And dang! I'm gonna hafta spend a month just to get caught up...