Cracked starboard exhaust manifold ('79 OMC 260)(PICS)

[HT32BSX115]

Re: Cracked starboard exhaust manifold ('79 OMC 260)(PICS)

A lot of times, the manifolds fit more than 1 engine..........But If I could use all the fasteners, I would use them. less chance for an exhaust leak.

Most will work. I think there's a year where the rear main seal changed and I don't know exactly what you have but I think you need to get an engine with the same seal arraignment or I believe you have to get a different flywheel/coupler or something etc.

I can't remember but stand by......someone will jump right in here with the correct answer on this one.

If I could go to the newer block and vortech heads I would probably want to do what it takes to use the newer engine style...... Everyone wants more power!

 

[Nivekt]

Re: Cracked starboard exhaust manifold ('79 OMC 260)(PICS)

A lot of times, the manifolds fit more than 1 engine..........But If I could use all the fasteners, I would use them. less chance for an exhaust leak.

Most will work. I think there's a year where the rear main seal changed and I don't know exactly what you have but I think you need to get an engine with the same seal arraignment or I believe you have to get a different flywheel/coupler or something etc.

I can't remember but stand by......someone will jump right in here with the correct answer on this one.

If I could go to the newer block and vortech heads I would probably want to do what it takes to use the newer engine style...... Everyone wants more power!

I was thinking along those lines as well regarding the exhaust studs. I can still get a hold of them at about $20/each.

Ill have to do some more research about the rear main seal details of the engine I have. I did a little looking around for rebuilt blocks online and did find that there were options out there that needed info on what seal arrangement I had in order to purchase the correct block so I understand what your saying.

I started looking into what it would take to physically pull the motor when I get around to it. Looks like I can pick up a simple chain hoist( http://www.harborfreight.com/2-ton-chain-hoist-631.html ) and either hook that up to a large tree branch or build a simple gantry. Sounds easy enough.

Newer sounds more expensive to me! Plus, Im pretty sure Im limited with how much more power I can run to the OMC 800 Stringer. I dont know that I would get any benefit from running a more powerful motor.

Oh, and I found a good use for the old risers....

 

[Scott Danforth]

Re: Cracked starboard exhaust manifold ('79 OMC 260)(PICS)

you can rent an engine hoist for about $10 per day from your local equipment rental place.

since you have a 1979 engine, you have a 2-piece. the easiest is to get and engine from 1985 or older (1986 is the start of the 1-piece seal). I think its possible to get a flywheel/coupling combo for the 86 and newer engines, I just dont recall.

 

[Nivekt]

Re: Cracked starboard exhaust manifold ('79 OMC 260)(PICS)

you can rent an engine hoist for about $10 per day from your local equipment rental place.

since you have a 1979 engine, you have a 2-piece. the easiest is to get and engine from 1985 or older (1986 is the start of the 1-piece seal). I think its possible to get a flywheel/coupling combo for the 86 and newer engines, I just dont recall.

Thanks for stopping by Scott. I dont think an engine hoist will be able to get up high enough and go in deep enough to pull the motor out of her unless you can suggest a certain type of hoist that would work for this application.

Also, thank you very much for the details about the engine. That will save me a lot of searching time to get the right short block.

*EDIT* Doing some more searching it looks like within the 2 peice main seal engines there is an option for a 2 or 4 bolt main seal. Forgive my ignorance, but what exactly does this mean and how can I determine what I have?

 

[Nivekt]

Re: Cracked starboard exhaust manifold ('79 OMC 260)(PICS)

Bump for help regarding my question in the previous post edit.

 

[HT32BSX115]

Re: Cracked starboard exhaust manifold ('79 OMC 260)(PICS)

Bump for help regarding my question in the previous post edit.

Hmm. I thought I commented on that..... A lot of engines have 4 bolt main caps. You'll see what you have when you pull the pan.

Doesn't matter, you're going to replace the entire block with either a 2 or 4 bolt main block. Racing people like 4 bolt main engines presumably because the lower end will handle a LOT more HP and RPM.

It doesn't really matter much to you. You're not going to turn the engine more than about 5000 RPM and you're not going to make enough power to matter.

If you get a short block and use your heads (which I wouldn't do unless the heads go to a machine shop for complete rebuild) you'll want an 85 or earlier block. There's a LOT of machine shops in the Phoenix area (you're in PHX?) ANY good machine shop will be able to hook you up with a good short or long block. (just tell them it's for a boat) ask around at marine places. They know where the best engines come from.

Otherwise get to a wrecking yard and find a good used engine out of an 80's Chev pickup.

 

[RogersJetboat454]

Re: Cracked starboard exhaust manifold ('79 OMC 260)(PICS)

*EDIT* Doing some more searching it looks like within the 2 peice main seal engines there is an option for a 2 or 4 bolt main seal. Forgive my ignorance, but what exactly does this mean and how can I determine what I have?

Sounds like you have a couple things muttled together....

Some small blocks could be equipped with two different types of main bearing caps.

2 bolt main engines (two bolts retaining every main bearing cap) were used in standard passenger cars, light duty trucks, and even boats.
4 bolt main engines (4 bolts retaining the main bearing caps for the center 3 caps) were used in heavy duty trucks, boats, industrial equipment, etc.

Pre '86 2 bolt and 4 bolt main blocks used the same 2 piece rear main seal regardless of how many bolts were used for the 3 center main bearing caps. In fact, the rear main cap is identical between the 2 and 4 bolt blocks, using 2 bolts to retain the cap.

So basically it doesn't matter if the block you choose is a 2 bolt or 4 bolt. As long as it's a pre '86, the rear main seal and crank pattern are the same.

Most consider the 4 bolt main to be stronger, and therefore more desirable for performance applications, so a 4 bolt will fetch a premium price. You do not need a 4 bolt block for a boat though. There are millions of 2 bolt blocks in boats that have lived a long healthy life. Again, it's your choice.

As far as lifting the engine out, you may want to consider building your self a gantry crane. Allot of folks on this site have done this for fairly short money using dimensional lumber (4X4's and 2X6's). If you look around you may be able to find pic's of the ones people have made. With the gantry crane, and a chain fall, you should have not problems lifting the engine out.

 

[RogersJetboat454]

Re: Cracked starboard exhaust manifold ('79 OMC 260)(PICS)

Sorry HT, I resonded before I saw there was a page two...

 

[HT32BSX115]

Re: Cracked starboard exhaust manifold ('79 OMC 260)(PICS)

Sorry HT, I resonded before I saw there was a page two...

I think it's good we're "on the same page"!!

 

[Nivekt]

Re: Cracked starboard exhaust manifold ('79 OMC 260)(PICS)

Hmm. I thought I commented on that..... A lot of engines have 4 bolt main caps. You'll see what you have when you pull the pan.

Doesn't matter, you're going to replace the entire block with either a 2 or 4 bolt main block. Racing people like 4 bolt main engines presumably because the lower end will handle a LOT more HP and RPM.

It doesn't really matter much to you. You're not going to turn the engine more than about 5000 RPM and you're not going to make enough power to matter.

If you get a short block and use your heads (which I wouldn't do unless the heads go to a machine shop for complete rebuild) you'll want an 85 or earlier block. There's a LOT of machine shops in the Phoenix area (you're in PHX?) ANY good machine shop will be able to hook you up with a good short or long block. (just tell them it's for a boat) ask around at marine places. They know where the best engines come from.

Otherwise get to a wrecking yard and find a good used engine out of an 80's Chev pickup.

Ah, thanks for spelling that out for me. I appreciate it. I will definitely have the heads rebuilt or just get new ones. I am in Lexington, SC and there is actually a machine shop right down the street from me. Never used them for anything so Ill have to get some references.

 

[Nivekt]

Re: Cracked starboard exhaust manifold ('79 OMC 260)(PICS)

Sounds like you have a couple things muttled together....

Some small blocks could be equipped with two different types of main bearing caps.

2 bolt main engines (two bolts retaining every main bearing cap) were used in standard passenger cars, light duty trucks, and even boats.
4 bolt main engines (4 bolts retaining the main bearing caps for the center 3 caps) were used in heavy duty trucks, boats, industrial equipment, etc.

Pre '86 2 bolt and 4 bolt main blocks used the same 2 piece rear main seal regardless of how many bolts were used for the 3 center main bearing caps. In fact, the rear main cap is identical between the 2 and 4 bolt blocks, using 2 bolts to retain the cap.

So basically it doesn't matter if the block you choose is a 2 bolt or 4 bolt. As long as it's a pre '86, the rear main seal and crank pattern are the same.

Most consider the 4 bolt main to be stronger, and therefore more desirable for performance applications, so a 4 bolt will fetch a premium price. You do not need a 4 bolt block for a boat though. There are millions of 2 bolt blocks in boats that have lived a long healthy life. Again, it's your choice.

As far as lifting the engine out, you may want to consider building your self a gantry crane. Allot of folks on this site have done this for fairly short money using dimensional lumber (4X4's and 2X6's). If you look around you may be able to find pic's of the ones people have made. With the gantry crane, and a chain fall, you should have not problems lifting the engine out.

Thanks also for the details. I guess Ill be looking for a 2 bolt main unless I happen to come across a great deal on a 4 bolt.

I did some looking around on how to build a wooden gantry. Seems simple enough although a lot of people are real wary about trusting one made out of wood. I figure if I beef up the beam real well using a few 2 x 6's bolted together it should be more than enough to handle the 575 pounds the long block is rated at.

 

[Scott Danforth]

Re: Cracked starboard exhaust manifold ('79 OMC 260)(PICS)

use 2x8's for your gantry - use 3 of them and you will be fine. if you want a 4-bolt block, look for a 1 ton or larger truck or RV.

 

[Nivekt]

Re: Cracked starboard exhaust manifold ('79 OMC 260)(PICS)

use 2x8's for your gantry - use 3 of them and you will be fine. if you want a 4-bolt block, look for a 1 ton or larger truck or RV.

Will do and thank you. Just waiting for the junk yards to open to start making some calls! lol

 

[Nivekt]

Re: Cracked starboard exhaust manifold ('79 OMC 260)(PICS)

Local engine remanufacturer wants $796.00 for a short block. I can get new heads for about $370 shipped or try to get them rebuilt. I have no idea what it would cost to have heads rebuilt though or if it would be cheaper than just buying new ones.

*Edit* Local place can rebuild the heads for $124/each. Not bad.

 

[HT32BSX115]

Re: Cracked starboard exhaust manifold ('79 OMC 260)(PICS)

Local engine remanufacturer wants $796.00 for a short block. I can get new heads for about $370 shipped or try to get them rebuilt. I have no idea what it would cost to have heads rebuilt though or if it would be cheaper than just buying new ones.

*Edit* Local place can rebuild the heads for $124/each. Not bad.

Using old heads are ok as long as they're not cracked and not too seriously rusty in the water passages...

They'll probably need to be surfaced.

You don't always have to replace valves if they'll clean up on a grinder, seats clean up ok and the guides are not "sloppy".

 

[RogersJetboat454]

Re: Cracked starboard exhaust manifold ('79 OMC 260)(PICS)

*Edit* Local place can rebuild the heads for $124/each. Not bad.

Is this just a quote over the phone, or have they actually looked at your heads?

If it's just a quote over the phone, expect;
The price to inflate, OR.... them to do half the work the heads may need, OR.... them doing a half a**ed job.

A good machine shop will look over the pieces before quoting any prices. There are so many variables to what the heads may or may not require to be serviceable, and the prices change accordingly.

Honestly the $370 dollars you were quoted for a pair of heads sounds really reasonable to me as long as they match the ones you are pulling off, and weren't rebuilt with a bench grinder.

 

[HT32BSX115]

Re: Cracked starboard exhaust manifold ('79 OMC 260)(PICS)

weren't rebuilt with a bench grinder.

!!That's a good one!!

(unfortunately, some are!!)

 

[Nivekt]

Re: Cracked starboard exhaust manifold ('79 OMC 260)(PICS)

Using old heads are ok as long as they're not cracked and not too seriously rusty in the water passages...

They'll probably need to be surfaced.

You don't always have to replace valves if they'll clean up on a grinder, seats clean up ok and the guides are not "sloppy".

Yeah, Im willing to beat they're toast. I have no way to know about cracks yet as I havent pulled them, but they are beyond rusty in the exhaust passages from what I can see.

 

[Nivekt]

Re: Cracked starboard exhaust manifold ('79 OMC 260)(PICS)

Is this just a quote over the phone, or have they actually looked at your heads?

If it's just a quote over the phone, expect;
The price to inflate, OR.... them to do half the work the heads may need, OR.... them doing a half a**ed job.

A good machine shop will look over the pieces before quoting any prices. There are so many variables to what the heads may or may not require to be serviceable, and the prices change accordingly.

Honestly the $370 dollars you were quoted for a pair of heads sounds really reasonable to me as long as they match the ones you are pulling off, and weren't rebuilt with a bench grinder.

That price was for either having my heads rebuilt or purchasing their rebuilt ones they carry in stock. Its a huge machine shop that services the entire region. http://www.cmengines.com/CylinderHeads/RemanufacturedCylinderHeads/tabid/68/Default.aspx

Several of the smaller machine shops I called all referred me to them.

 

[RogersJetboat454]

Re: Cracked starboard exhaust manifold ('79 OMC 260)(PICS)

That price was for either having my heads rebuilt or purchasing their rebuilt ones they carry in stock. Its a huge machine shop that services the entire region. http://www.cmengines.com/CylinderHeads/RemanufacturedCylinderHeads/tabid/68/Default.aspx

Several of the smaller machine shops I called all referred me to them.

Sounds like they are in the reman business, which is a little different then just your standard machine shop. I would go for their off the shelf reman's. No waiting. No SURPRISE your's are cracked!!! Or need new valves, springs, and guides.

Just as long as they can match the combustion chamber size to what you're pulling off, which should be no problem considering the heads you have now are truck heads that are as common as belly buttons, you should be good.