machine shop recomendations

[stratos201]

Hello everyone. I need to have my 1989 200 hp block bored again after a machine shop screwed it up. My motor is in the Jonesboro, AR/Memphis, TN area. Can anyone recomend a good marine machine shop? I also need a sleeve put in. Also, what kind of piston ring gap should we be looking for? Any help is appreciated.

I do have a clyber manual but I havent found the ring gap info yet.

 

[wilde1j]

Re: machine shop recomendations

Can't recommend a machine shop, but get an OEM manual if you're going to do the rebuild. Dhadley on this site can suggest good rebuilders.

 

[stratos201]

Re: machine shop recomendations

Hello Wilde1j. I dont own a factory manual but we do have acess to one from the local shop. They also let us use the rod alignment tool. A little history on this project: The engine ran good after the last rebuild for about 2 hours and then started having problems. The compression started getting lower and lower. We took it apart and measured the cylinders and found that the top of the cylinders were an average of .004 over what they were supposed to be and the bottom of the cylinders were about .011 over what they were supposed to be. The engine finally got where it would not really do more than idle. I think that we can put it together ok-we know a little more than last time. I am still very open to suggestions. Dhadley advised me about putting in the new stlye piston (wiesco 3143 I think). We just want to put this thing together 1 more time and be done with it. Thanks. hope this helps you to help me.

 

[Lakester]

Re: machine shop recomendations

hello,

one area were most engines run same specs is with conventional engine ring gaps. .007 - .017 is pretty standard. 4 or 2 stroke. .021 is too big, but for a worn out engine, snugged up else where, too it will run ok. but u will note if 4 stroke oil gets dirty faster. most fresh engines shoot for around .010 - 012. u do see the larger gaps .015 - .021 + on engines where the combustion mixture is additionally compressed such as with nitrous and or supercharging due to addl heat produced.

so shoot for .010 - 012 for normal use. if WOT lots or most of the time, i would opt then for .012 - 015. ring needs to be perpendicular to bore to measure. most engine builders seat it with the piston.

a sometimes WOT engine i would be ok with .008 to .011 or so. buzz it, for less tha 30 - 45 sec at WOT and the throttle back to let it all cool down some. maybe 15- 20 secs is better. cavet emptor~

if they get too tight or u butt gaps hard, u can break them in two.

be sure the rings u use are faced correctly for ur application.

be sure to break the 4 sharp sides of each gap end [2 per ring] at the ring split. std ops for good engine building technique. use a small file.

and for my bet, never install rings by hand. always use a ring expander.

sorry to hear u have to do the work over...

regards

lakester

 

[ezeke]

Re: machine shop recomendations

Before you send that block off, take a good look at the mating surfaces where the cylinder head gaskets go. If there is serious errosion there, your resleeve will need a flange and the job may be very expensive. L A Sleeve can provide the proper sleeve, but you may just want to find another powerhead. [LASLEEVE. COM]

 

[Dhadley]

Re: machine shop recomendations

I'd suggest Mar-Fab in Sparta Tenn. Real good guys and know exactly what they're doing. They can sleeve or do about anything you need done, no big deal.

As for the ring gap, the older service manuals will say .007 to .017. With the ring material they use today it's not uncommon to see .021 to .023 on a new ring.

 

[GeneH]

Re: machine shop recomendations

As stated above, get a factory manual. If you're into one this far, it is a must have. Forget the aftermarket manuals. They just get you into trouble.

 

[stratos201]

Re: machine shop recomendations

I appreciate all the help on this thing. Here is what happened exactly. I can start a new post on this if needbe but here it is in the mean time. My dad and I put the motor back together and I brought it back home. It wasnt running very good on the muffs so I took it over to my mechanic and he rebuilt one carb again. It was starting hard so we put a primer on it also. At that point it was running and starting good. I took it out for some breakin time and it ran pretty good. Just as I started to put it on the trailor it died and didnt want to do anymore than idle. The mechanics shop is only a block away so I stopped by and we put some plugs in it. We thought that the low rpms along with the heavy oil mix fouled them out.

I took the boat out again a few weeks later and it died on me and wouldnt start. After a tow back in I took it to the shop and droped it off. He called me a few days later and told me that the compression was down to about 40-50 pounds in all cylinders. We took the heads off and started poking around and found that the cylinders were about .004 big at the top and about .012 bigger than they should be at the bottom. His thoughts were that it was not getting much compression until the piston was most of the way up to tdc and that the rings just could not compensate for the bore being to big. That brings us to the current situation of looking to have the cylinders bored, new pistons, one sleeve (because that cylinder was already .040) and such. Do you guys have any suggestions as to the best direction and or opinions as to what might have happened. The motor saw about 2.5 hours on the water before loosing compression. We did not run the vro, only used premix. Thanks guys.

 

[wilde1j]

Re: machine shop recomendations

Can't tell from here why the motor crapped, but make sure you find out why or it will happen again. Carbs causing lean mixture is one of the most common causes, but the are a lot of other possibilities.

 

[stratos201]

Re: machine shop recomendations

Can cylinder sleeves be put in outside a machine shop? (at home) by heating the block and removing the sleeves by hand? I heard that they could but what would be the pro's and cons of doing it yourself besides money?

 

[Dhadley]

Re: machine shop recomendations

Some blocks have "removable" sleeves and some have cast in sleeves. The block in question (V6 looper) has "removable" sleeves.

It wouldn't be right to make a blanket statement saying it couuld or could not be done at home. Anyone with the right equipment can do it. You need a stove and a freezer, a tool to hld the sleeve in position and a mill. Then you need a boring bar, a hone and a dial bore gauge. Naturally all the cleaning equipment too.

To me it's always cheaper to have a Marine pro like Mar Fab, rather than an automotive shop, to do that type work.

Don't you agree?

 

[stratos201]

Re: machine shop recomendations

After hearing it that way-definitely. I guess I am like everyone else, I want to do it right but for the least amount of money. It is not worth dealing with on my own and risking screwing it up rather than spending the money to have it done. As always, I appreciate the information and the help from everyone. Mar-fab it is.

 

[Dhadley]

Re: machine shop recomendations

When you talk to them let them decide if it needs sleeving or not. They have ways of fixing some things that may not require sleeving. Talk to Kurt if possible.