• Welcome to the Checkmate Community Forums forums.

    You are currently viewing our boards as a guest which gives you limited access to view most discussions, articles and access to our other FREE features.
    By joining our free community you will be able to:

    » Interact with over 10,000 Checkmate Fanatics from around the world!
    » Post topics and messages
    » Post and view photos
    » Communicate privately with other members
    » Access our extensive gallery of old Checkmate brochures located in our Media Gallery
    » Browse the various pictures in our Checkmate photo gallery

    Registration is fast, simple and absolutely free so please, join our community today!

    If you have any problems with the registration process or your account login, please contact support by clicking here or by using the"contact us" link at the bottom of the page.

TURBO

F

Fuelblender

New member
Ok guys here it is, 17' Checkmate, looks like a drag boat hull,. 1977:popcorn:
Four Cyl. Chevy 181ci. Iron Duke. Runs great, I balanced it all and took out that four cyl. vibration. I bought a turbo (Marine set up for this motor"
Turbo needs bearings but it is all there. Not sure what it ever went on?.
It will mount right where the Rochester 2GC is.
I know the 165HP inline six could accomadate a Quadrajet.and have a chance for an inline 6, in that boat it will pull a 23P prop.
But interest in the turbo setup!!
 
Yes, I'll get one, not even sure what model it is. I ask in the decal post about new ones and everyone was very helpful.
 
May have been a typo but that is a 151 inch motor not a 181 and its a Pontiac engine...not a Chevrolet. .

I had a Opel in Germany when I was in the Army that had the same basic motor but with fuel injection and a turbo that was a good solid 150 MPH car. 210 HP if I remember right. Should twist a 23 pitch prop on a small ish boat into the 60's.
 
I beg to differ.

bdwq69.jpg
 
Pontiac Chevy? Ok.
But when I rebuilt it I had to use Mercruiser pistons, $100.00a whole, and 181CI timeing gear. The piston pin height is differant, but balance of the assembly is the key, it is hell on valve springs. I can turn a 21" 5500rpm
after breakin, now only about 5300, that is winding pretty good for a four banger.
 
The iron duke 151 was a Pontiac motor . They called it a GM motor later on and stuck all kinds of different badges on it including chevy in the 80's but it was still a Pontiac. You are right though. the 3.0 181 was the Mercury Badged version from GM. .
 
There was a Mercruiser 165hp inline six, that is a great motor also, always thought it would be great, with a 4" bore you could run a 350ci Chevy piston, and it had a 4 barrel adapter under the 2GC mounting. Once in Hot rod Magazine a guy built in 6 inline, and got over 800 hp that was in a 62' Vette drag car, neat concept.
Would still like to know how the turbo would do on a four? I guess depending on the turbine rotor the power band could be sized for the rpm range you were looking for.
 
It's been a while since I looked at stuff like this, so I'm a bit rusty.
But I guess you have already looked after the motors needs to add the turbo. Stuff like ~ 8 to 1 compression, quality pistons and rings, quality exhaust valves, a proper cam and timing curve.
More power in a boat is always a good thing, but since allot of work is done at low rpms in a boat. I think you might want more displacement if you can get it or like you said a small wheel on the turbo so it spools fast. A low compression 4 cyl even in a small boat might feel rather lazy and struggle to get on plane.

Sounds rather expensive for an older boat, hope you plan to keep it a long time.
 
A good place to start looking for advice on turbo selection might be Ford SVO guys. They run 2.3's with all kinds turbos. They would be a good source of info for a good low end power turbo on a 4cyl. I have been experimenting with turbos for a few years on my 3.8 Buick motor, and I can say this, for a fast spool, spend the extra money and get a dual ball bearing turbo. I just did and actually went from a 70mm journal bearing turbo to a 67mm DBB, and I gained almost 100hp to the wheels with a smaler turbo. This is all with the exact same exhaust housing. It spools up that much faster and my torque curve moved way to the left. So it was worth the extra money.
 
Compression is mild approx. 9:1, haven't look at the cam specs. A little more investigation. But would think for the average Joe it can't be to radical change.
 
You must log in or register to reply here.
Back
Top