Gung's 115 hp 1974 Overhaul so Far

[gungalunge]

A badly siezed engine on #1 cylinder with A hole through the cylinder top. THe Mercury 115 1150 is 32 years old.I stowed all the parts in tupperware boxes. I had to get a used engine block on eaby.This engine came with a useable block and crankshaft.I checked the cylinders with a bore gauge.It needed the Cylinders bored. So off to the machine shop it went.They bored it .030 oversized. With the parts removed the block weighs @48lbs. $29.00 to ship ups ground.One way . It took about 2 weeks to get it back "Ohio To Florida . Not too bad.. Durring that 2 weeks I purchased a Seloc on line service manual.From I-boats it came as a full service manual book and a 1 year online subscription nice real nice.I began the rest of the work. following the manual.That manual clearified all i need to know about what parts I needed to order.The beauty of on line ordering on the web<br />the parts came in a few days right to my house.

 

[gungalunge]

Re: Gung's 115 hp 1974 Overhaul so Far

Continued.I then loged on the forums here.When I had questions or posted what Have been doing so far on this engine.The group is the greatest I followed my manual and put all the bearings on the crankshaft.Installed the connecting rods and rebuilt my carborators and fuel pumps.The gasket scrape down and clean up was some bit of work.<br />I am a master Nissan Auto Technician.Most of the tools I had available. Except I had to pull Out my american sized wrenches .. Now I got to square away putting .030 Oversized pistons still making that desision yet.WHat pistons to buy ? and I wonder since the bore was cut .030 bigger what would the cubic inch displacement be now ?I got to find the formula and do the math anyone out here know what that may be ??? Then it is assembly time .I cannot wait to get all these parts together .I am not looking forward to compressing the piston rings and getting past that part.I hear Use Fat radator clamps and line those rings up in the ring groove divits or they break.THe poor man's ring compressor. OR should I stop and buy the factory tool set ?????

 

[jheron]

Re: Gung's 115 hp 1974 Overhaul so Far

Look HERE to see how I set my pistons and so on (towards the bottom)If you have any further questions don't hesitate to ask <br /> I now have 75 hours on the rebuild and she runs like a top! <br /> I would talk to clams about sierra after market pistons they are persian pistons and are the same as oem. I have heard many times that the inlines don't like the wisco forged pistons so beware.<br />Regards Jon

 

[Chris1956]

Re: Gung's 115 hp 1974 Overhaul so Far

Gung, The Mercury Shop manual calls for six piston ring compressors (some are offset, some straight). I have never had access to these, so I put the pistons in using my fingers and a screwdriver or two to compress the rings. It is not too hard, but requires I remove the connecting rods from the crankshaft. I number paper cups (1-6) to hold the roller bearings and cages. <br />I have heard that you can put the pistons in without these tools, while the rods are attached to the crank, using some wood to hold the crank in the correct position, but never seriously tried it.

 

[AEROCOOK]

Re: Gung's 115 hp 1974 Overhaul so Far

Hey gungalunge, how is the project coming along?<br />I also have a 1974 1150 project motor and I have been following your post looking for an update.<br />Now that the snow here in Ontario is gone, my motivation is starting to come back and Im hoping to start mine up soon.<br />Will CONSULT work on these motors? (inside joke)

 

[gungalunge]

Re: Gung's 115 hp 1974 Overhaul so Far

I lost some motivation due to back surgery.My engine block was sent to F&S machine I asked them to bore it .030 oversize all 6 cylinder durring the 2 weeks they workied on it I rebuilt my carbs ordered a seloc online manual.each day since i am off work for a while this project has helped rehabilitate me my health .I got the crankshaft on the floor did all rebearinged, and my reeds blocks check out good I have two crankshafts to work with so i noticed larger reeds on the one so i used them off the other crank they will work checked them in the manual. The standard c.d.i.is 99.8 with the bore I now have a 101.885 2.57263liter engine now .calculated bore x bore x stroke x .7854 =cdi in my case i got 2.1 extra cubic inches . crazy things prohibit me at this time the cash and doctor appointmets , But soon i will buy my pistons and be on track again the lower end is done new bearings and grease too and the water pump bases and inpeller all done. I found old rubber blade peices floating around in the intake passages i was shure to get them all out ,so the very last thing i need to do is buy the pistons and move on to getting out on the water .this block sitting here got cylinder walls just waiting for pistons.also the carbs have these tiny holes under the throttle plates i had to poke dirt out of them with a peice of tag wire all three carb had one or two plugged . and my stator wires were a bit exposed ,i fixed that with star brite liquid electrical tape .the distribitor rotor shaft bearing top one was bad it is new now.I took out the ohm meter to the plug wires and two of them were not conducting . the clips were pulled loose and I am going to try the ngk spark plugs instead of the champions and want to be soon to brag about how my 32 year old goes on the water but not yet i got to finish ..

 

[gungalunge]

Re: Gung's 115 hp 1974 Overhaul so Far

ok I got the pistons ended up getting wiseco 3109p3 6 new ones .. much different than the ones it originally had in it ..If someone said put 12 of those wristpin clips on again i whould have to shoot myself ihad a rough time with those. I used the factory ring compressors to get the pistons in that was nice.I checked for good centering on my crankshaft and end play all worked out with a copper shim on the front end cap. beautyful. I got .016 ring gaps no all 6.and it turns over so easy. I think i am good .<br />I gasketed it all up with new bolts and locktight. it is time to put this powerhead on the lower unit. I got alot of time invested overhaulin.sure feels good getting all these parts back together.

 

[Clams Canino]

Re: Gung's 115 hp 1974 Overhaul so Far

GAK!!<br />I've posted several warnings here about using Wisco's in the specific application of the inline 6. Genuine Mercury or Persan is reccomended. Search on " Wisco in inline" for details. Odds are you'll be OK. But with the other two brands - you aren't playing any odds at all.<br /><br />-W

 

[gungalunge]

Re: Gung's 115 hp 1974 Overhaul so Far

I masking taped the holes closed.and shot the engine down tonight with some Phamtom black .wow it looks good not the best but ok for me . I think i am 3 weeks away now getting it going on my boat. starting to see day light ..last week end i painted the boat trailer with a soar back.good theropy ..

 

[gungalunge]

Re: Gung's 115 hp 1974 Overhaul so Far

clams I did not like how the piston pin and those spacers looked when done how it floats there <br />with a gap I question that but i will try it ..it seems that more should come with the kit to trim that up

 

[gungalunge]

Re: Gung's 115 hp 1974 Overhaul so Far

the machinest told me not to worry about that. as long as the bore was straight .and the crankshaft was set in with the right end play . well i will see what happens .. I stared at that .. and just dont know .. this is my first 2 stroker i ever rebuilt .. with the neadle bearings .

 

[Clams Canino]

Re: Gung's 115 hp 1974 Overhaul so Far

How easily did the piston pins push in? Need to warm the pistons up at all, or did they slide right in almost "too easy".<br /><br />-W

 

[Texasmark]

Re: Gung's 115 hp 1974 Overhaul so Far

On your new cubic inches, you started with 99, I guess, as I think all of the later towers were that. <br /><br />The calculation for cubic inches is area of the piston x cylinder depth (stroke in this case) x # of events (6 cyl) = 22/7 x [1/2 diameter of piston (radius)] squared...like pi x r squared (just the r is squared) x the stroke length x the # of holes.<br /><br />Since this is a product (multiplication), you can take the old and new radius ratio and get your answer if you choose which is merely alculation of piston top area with new diameter/ published area calculation x 100% and as you'll see later, the number is about a 2% increase.<br /><br />Say the old piston diameter is 3.00". Then that part of the calculation is 22/7 x 3.00/2 squared = 7.0686<br />-----------<br />Let's see how close my guess is and we will be back. Then for cu in displacement we have that number (we just calculated) x an assumed stroke (say 2.5") x 6 cylinders = 106.029..(we were shooting for 99)....pretty close guess on the original engine's dimensions which I don't know.<br />-----------<br />So, you do the math.<br /><br />22/7 (pi) x [Orig diameter/2(radius)]squared x published stroke x 6 cylinders.<br /><br />Then redo these numbers but this time instead of using the original piston dia/2 add your .030 bore to it and you will have your answer.<br /><br />Carry it out to 4 or 5 decimals as your overbore was 3 decimals and the number isn't going to change a lot.<br /><br />---------------<br />Example: New numbers (guess) 22/7 x [3.030/2] squared x 2.5 stroke x 6 cyl = 108.1599 cu in compared to my initial guess of 106.029 or a 2% increase in cu in.<br />------------------<br />And if anyone is raising their eyebrows, I am retired and I need to keep my brain active....somewhat, not too much. Grin.<br /><br />This is an excuse to dust a little dust off it.<br /><br />HTH<br /><br />Mark

 

[gungalunge]

Re: Gung's 115 hp 1974 Overhaul so Far

the piston pins pushed in very easy no heating they just slid in with one finger pushing them in but those snap ring clips were tough at first . after the forth one .i began to master it. The C.D.I FOr a 115 1974 is 99.8 Cubic inches . With the bore in each Cylinder .030 over bore 2.905 and stroke 2.562. I now caluclated it at 101.885 cdi.or 257.263 cubic centemeters . SO here it goes you muliply; bore x bore x stroke x .7854 = cubic inches ..

 

[gungalunge]

Re: Gung's 115 hp 1974 Overhaul so Far

oh yea x 6 cylinders

 

[gungalunge]

Re: Gung's 115 hp 1974 Overhaul so Far

ok and the progress so far : I Installed the power head today it is all together.I question the setting of my distribitor. I used the dial indicator method to find tdc On #1.I painted a mark . there is no timming scale on my flywheel. the sticker is missing.I got spark .I did not put fuel to it yet. it got late.I put her in it took me 12 hours. I messed up on the shift lever . and had to go back and redo that .I need to put it in that water.and do the testing I hope it will run ..mix some fuel up and fill my lower gear unit i put all new bearings in that too. I am excited that it is all together and I hope it runs right.

 

[2cycle]

Re: Gung's 115 hp 1974 Overhaul so Far

Be sure you have your battery fully juiced up because my rebuild/1500 was very tough to turn over with the added compression. Good luck, and hope you get it dialed in just right!

 

[Clams Canino]

Re: Gung's 115 hp 1974 Overhaul so Far

Originally posted by gungalunge:<br /> the piston pins pushed in very easy no heating they just slid in with one finger pushing them in

THAT's what scares most me about Wisco, the pins are too loose of a fit. Make sure it's propped on the light side to help eliminate stress to the piston pin journals. I've seen a couple failures there.<br /><br />-W

 

[Texasmark]

Re: Gung's 115 hp 1974 Overhaul so Far

Hey you mechanics out there......I thought you had to press piston pins in (any piston) to prevent slap....like a slight interference fit?....beins the pin fits the piston and the rod is what moves on the pin...since the rod is hardened or inserted whereas the piston is soft aluminum.<br /><br />Sounds like gun is in for some ticking when he gets it running and will be wondering where it's coming from and will be getting progressively louder as the engine wears.....Hmmmmm<br /><br />Mark

 

[gungalunge]

Re: Gung's 115 hp 1974 Overhaul so Far

Well i have not started it yet.It should be ready. I am going to take it to the lake and start it in the water. i do not fully know how to use the flush ears and how safe that is . ANy advise ?? I never seen it done or how it works.will it fit on my engine? or is it for newer engines? I did not atempt even spinning it with the starter. As for the piston pins the pin slid in to the piston then goes through a group of roller bearings around connecting rod and a snap ring on each side of the pin .to keep it in place .there was no force where as pressing was needed . i will see when i get it going if it knocks . I would like to try the some way of starting it before i go to the lake so i can test the fuel pumps and carbs and get a few settings right before i test it at the lake . I suppose i need to run it in neutral by disconnecting the shift linakge too.. so the prop don't spin if i use the flush hose method ..