4cyl to v6 upgrade

[fast_eddy]

All,
I am paying a mercruiser certified tech to change a 470 inline 4cyl with a 4.3L V6. As I have been waiting 6 months for this project to be complete needless to say I am getting anxious. This is the first of these type of engine swaps my mechanic has attempted. The last hurtle he is attempting to cross is the exhaust y-pipe. My outdrive is an alpha1 gen1 with the old style gimbal housing. Needless to say the bolt pattern on the V6 y-pipe doesn't match. What are my options here? I was informed today that with the outdrive installed, the connection leaks water and exhaust into the bilge. Is it possible to change the gimbal housing to the new style that will mate up to the y-pipe? If so is the gimbal housing all that would need to be changed?

Thanks in advance

 

[180shabah]

Re: 4cyl to v6 upgrade

I would be nervous - he didn't match the y pipe to the transom shield?

It would be cheaper to swap the y pipe than the ENTIRE drive assy.

 

[xltier]

Re: 4cyl to v6 upgrade

is thru hull exhaust a option.?then u take the pipe off and make a plate.

 

[fast_eddy]

Re: 4cyl to v6 upgrade

I would be nervous - he didn't match the y pipe to the transom shield?

For someone who knows nothing about this please help me understand the parts involved here. What part does the y-pipe bolt to? I understand the y-pipe change, however I have been told there is no y-pipe for a v6 that will mate up to this assembly.

 

[fast_eddy]

Re: 4cyl to v6 upgrade

I have been reading about the thru hull exhaust as an option. In fact the mechanic suggested investigating that today. I am concerned about the noise. How noticeable will this be in the boat. The lake I boat on does not have noise restrictions. What parts would be necessary to accomplish this?

 

[spanishmackeral]

Re: 4cyl to v6 upgrade

Why not get the y pipe for the generation outdrive you have then it would be a direct bolt on, should be able to get one on ebay for a reasonable price.

 

[Howard Sterndrive]

Re: 4cyl to v6 upgrade

I agree - the correct pipe for gen 1's are a dime a dozen compared to the cost of going thru hull. Plus V6's don't sound good thru hull. It's unlawful in some areas too.

 

[180shabah]

Re: 4cyl to v6 upgrade

What part does the y-pipe bolt to?

Y-pipe bolts to the inner transom shield, right now with the 4 cyl in your boat ther is a single pipe for exhaust that only comes up on one side of the engine. Y-pipe would replace this.

I understand the y-pipe change, however I have been told there is no y-pipe for a v6 that will mate up to this assembly.

This is pure BS. The drive assy is identical (though the gear ratios are different) on ALL engines from 4 cyl through big block V8s. The y pipe is the same on v6 and v8's. Your mechanic is really trying to sell that thru-hull exhaust.

 

[Cptkid570]

Re: 4cyl to v6 upgrade

The difference between a Gen 1 y-pipe and a Gen II y-pipe is that on the Gen II, the bolts make more of a square pattern and on the Gen 1, there is one bolt that is kinda staggard.

To buy a brand new Gen 1 y-pipe would be hard to find and expensive, but a used one would be under $100.

If you look at this, scroll down and it has an illustration of the 2 different bolt patterns.
http://cgi.ebay.com/ebaymotors/MERC...ear?hash=item27aa4c7eb3&_trksid=p4506.c0.m245

 

[Cptkid570]

Re: 4cyl to v6 upgrade

Ask your mechanic, but this one may fit yours:

http://cgi.ebay.com/ebaymotors/Merc...ear?hash=item1e57bffc17&_trksid=p4506.c0.m245

 

[Howard Sterndrive]

Re: 4cyl to v6 upgrade

hmmm. Maybe the 170 (224 fordcruiser) inner transom plate has a different shape hole for the 224 unique exhaust?
Is this fitter using the same inner transom plate?
I thought the spacing of the rear engine mounts was different from V6 Chevy (?)
Not sure how your engine is mounted....