V4 questions

[Fuzzbutt]

So I was out 2 Sundays ago and the lake was quite cold already. Seems I had more heat in my #1 cylinder's piston than in the block cause it looks like I fatally damaged that piston with a cold seize.

So over the winter I guess I'll be rebuilding my 100 HP Johnson V4 since it is no longer running. Good news is the block seems to be in good shape. I still make 135 psi compression in #3 & 4 and 125 in #2. 70 psi in the bad cylinder.

What are your thoughts to putting a bubble back exhaust on her? I have one with the fillers but I know it doesn't fit directly.

[MarkS]

I asked that question a couple years back over on FG about "hopping up" a 115hp with that mod., and Scott (Chinewalker) was probably the most trusted "guru" racer on board at the time.  He advised that there was machining of the block required to make the bubble butt plate most effective, and carb. changes/upgrades were also required to balance everything out in the end.  The general consensus was that money would be better spent finding a larger displacement power head for the conversion, ie: find a 135-140 from the same era and go thru it before bolting it to your mid section.

Doug has been collecting some hot rod V4 (CrossFlow ?) parts lately, maybe he can shed more light on the subject?  Sorry to hear about your motor trouble Fuzz, at least it happened at the end of the season!  (Not much consolation, I know right?) 

Edit: Found two old threads on the subject;
http://www.fiberglassics.com/fiberglassics-forums/home/j-e-g-o-s-place/a-quick-question-about-bubblebacks#37783

http://www.fiberglassics.com/fiberglassics-forums/home/j-e-g-o-s-place/bubble-butt#46103

[Fuzzbutt]

Thanks Mark. I'll check them out on the computer when I get home.

I have a spare block and saw the slight cutting needed to fit the shapers into the exhaust. Looks like a great way to increase flow and lessen the resistance to change in path after the exhaust is pushed out of the cylinder.

I've had about 8 hours of runtime this year. Less than a quart of oil was poured in.

I think I needed to pull it apart but hope to do it as maintenance not as a necessity

[V153]

Depends. The block has to have the lugs on which to mount the fillers. Some blocks don't.

I've heard tale of people running 'em without fillers and actually gaining a couple hunnert rpm up top. But doing so puts a dent in the mid-range acceleration.

Yes. Machining is recommended. Particularly when yer mixin motors.

[Fuzzbutt]

Well my 1988 88 hp block has the bosses where the fillers screw to. But if you place the fillers on them they are proud of the surface about an 1/8". I'm not sure I'd want to use that block for anything and I haven't yanked the flat back off my 100 yet to see if the bosses are there.

After looking at the 88 though the difference between flat back and bubble as far as how the exhaust glows is profound. There's got to be a huge restriction and back pressure basically dumping all the spent gasses in a small box and making the gasses find the square exit at the bottom. It looks like if any machine needs to be done its minimal and the block will go back to flat if needed. If the fillers were a tad shorter the block would be good to go. I'll take pictures of what I'm talking about tomorrow in the daylight.

I'm swapping reeds out too. As well as replacing the fuel pump.

Wish I could sell the 12 gallons of 80:1 fuel to someone close by that might use it before winter.

[V153]

I'm swapping reeds out too.

Factory crossflow steel reeds are all the same regardless of model/hp. Getcha some carbon fiber reeds from Boyeson, or better yet Chris Carson. You'll get better mid range and you'll never have to worry 'bout the motor trying to digest a steel reed.

[Jerry]

Chris is great.

[Fuzzbutt]

Chris Carson reeds are the plan. Similar to the ones my sled uses. I'm not too fond of the boyeson reeds.

[V153]

I'm not too fond of the boyeson reeds.

Y'know I hear people say that but when I ask em why they usually don't have a very good excuse. I ran em in street & dirt bikes for years with no problems. Have you had a failure?

Speaking of snowmobiles check this out: Crank bearing in a Polaris 700/1050 is the same as what's in a crossflow. Found this digging through a box of parts that came with the 9 page motor. Identical part# on the race. Good find cuz I still needed one for the 140.

Back on subject. I don't think you can go wrong with Chris Carson's stuff. He's been doin that chit for a long time.   

[Fuzzbutt]

Well I have a Yamaha and after clearancing the reed cages a smidge no other mod needs to be done. the Stock plastic looks very similar to that design that Carson uses. I've never had a failure of a reed but know of others that have. My 600 even sneezes when it's cold and no damage yet.

For the price the Carson's seem a better deal. 

[Fuzzbutt]

Quick but not so easy question about these motors.

I have a line on two different motors one of them is a 120 V for looper but it isn't complete and the other one is a 79 140 crossflow that is complete but is out of unknown condition. The 120 is missing the cover and lower unit but I have a spare lower for a cross low and the part numbers online seem to match up. Any thoughts to which might be a better buy?

Both are under $600.

[V153]

Think I'd go with the complete motor. You're already familiar with the crossflow design.

Not so sure about the easy swap on the gearcase from xflow to looper. Think the shift rod is different, and a couple other subtleties to P ya off. Plus why go from having parts to needing parts?

Nothing wrong with loopners I spose. They're a lil more economical than xflows. But they're heavier ... Need I say more? Heh heh heh











 

[Fuzzbutt]

Well I laid a deposit down on a '79 Evinrude 140943R today. I'll be going to pick it up in about 3 weeks somehow. It's 500 miles from here. I know it's my second outboard purchased for around $500 without knowing if it even runs first. My 100HP Johnson is a great motor and I bet I can still yank it apart and fix it to make some cash if I want.

This 140 needs a bit of cleanup and it's a terrible blue color. I think I might be repainting it the dark charcoal color or something more flattering to my silver CVX16.

I'm planning on putting it on a stand here in my garage after I pick it up. I'll give it a good once over to check it's condition. The current owner wasn't hip to it's condition. There aren't any extra holes in the block so it should be useable even if I need to tear it apart and replace all the gaskets and rings.

Best part is I'll be able to use the same rigging I currently have. I won't have another 75 pounds hanging on my jackplate and I have some spare parts I'll be able to unload to finance this.

Now to upgrade the fuel system to the primer style?

[V153]

Now to upgrade the fuel system to the primer style?

Probly have the parts you need, hardware wise. Not sure I got a spare pump. Might have most of one. Lemme see.

[Fuzzbutt]

I won't know what I even have for a few weeks. Should be interesting. Still thinking about what color I would want it cause the blue color it is right now isn't glittering and will clash with my new cover. I'm leaning towards the charcoal color OMC used or white or black.

Besides a switch away from the choke I am thinking about adding an electric fuel pump and/or at least replacing everything fuel line related on my cvx16 to good quality 3/8" stuff. I'm not sure exactly I melted a piston but my glass fuel filter fell apart when I touched it last October. At the very least I'm putting in a good screw in filter.

[MarkS]

If you can find room up under the splash well there's no better filter - water separator than the Racor 120RRAC01 for out boards Chris, IMHO.   You can find them on Ebay for about what we pay for them, I'm just sayin'..........

[Fuzzbutt]

That's pretty much the filter I'm looking at. Either that or something very similar to it. The 10 micron filter is a bit too much for the low pressure side. The larger ones aren't bad. The recommended 4"Hg max is a challenge with the 10 micron. I will not have another fuel starvation/air in the line issue. I'm pretty sure that's what burned up my 100.