7mgte ski boat?

wiseco7mgt

dirty mechanic
Aug 12, 2007
811
0
0
queensland
So this idea came about as i wanted to get back into wakeboarding, a sport i was big into several years ago now.
I've been looking into a ski boat and prefer the inboard but most of the inboards are v8's for obvious reasons. My idea is to get a boat that's hull is in good conditon and pull out the v8 and refit with a 7mgte, but as it' only ideas stage i welcome all criticism on the idea and would love to hear from any one who has already done this or has put any real thought into the idea.

The reason i thought 7mgte was the torque on take off would be great and being a wakeboat it doesn't need to go all that quick just have heaps of grunt and make a nice fat wake. I already have heaps of 7m goodies left over like s/s headgasket both 1.2mm and 2.0mm, arp's, plenty of spares and coolers, gaskets coils e.t.c, Was thinking of useing a block i have in the shed and going for a high compression engine with a fast spooling turbo with a max of 350-400 flywheel h.p so a cheap ct57 would be ideal.
I would like the intercooler to be a watercooled job for obvous reasons and have a choice of either a stock 7mgte ecu with afm or go with my spare 7mgte map based ecu(turbo-a).
Im thinking stock ecu as my power goals are relatively small and that way i wont need to stuff around with tuning a map on the water just use the timing and the afpr for that(with a wideband up front).
So i have heaps more ideas but would love to hear any comments or advice from those that have already played around with them in the water or at least thought about it.
No i haven't been drinking!(yet)
 

Doward

Banned
Jan 11, 2006
4,245
0
36
Alachua, FL
I'd love to put a 7M into a boat.

Go with an air to water intercooler, and you've got PLENTY of cold water to make for a super efficient intercooler system ;)
 

crisp

existentialincrementalist
May 25, 2007
1,785
2
38
Ohio
IIRC... the Toyota straight six is originally a Yamaha BOAT MOTOR design at heart in the FIRST place, no?:aigo:



Can anybody confirm that?:icon_surp




-crisp
 

GrimJack

Administrator
Dec 31, 1969
12,377
3
38
56
Richmond, BC, Canada
idriders.com
Depends on where you are located, I'd say.

In North America, you'll have better luck with a domestic V8. Displacement makes for less wear in the long run, and those boats tend to run at high throttle for long periods of time. IMO, I'd want to build for double what I'm going to run most of the time - building an engine for 350-400hp and then running it at that level is asking for an engine to blow up. Building a 7M to 700-800hp is, well, technically not as easy and certainly a lot more expensive than a comparable V8 setup.

Plus all the parts are already easily available, nothing to fabricate, really.

If you're really looking for nice torque down low, why not look into a nice diesel? They kick the crap out of gasoline engines for raw torque.

Wonder what effect, if any, running saltwater through an Aluminum head / Iron block combination would have?
 

Poodles

I play with fire
Jul 22, 2006
16,757
0
0
42
Fort Worth, TX
ewwwwww


I was gonna get to the salt water part. The jet turbine race boats have major issues with the salt water spray (it EATS the turbine blades), so I could see it doing the same to a turbo as well.

If it's fresh water, I don't see it being an issue.
 

IJ.

Grumpy Old Man
Mar 30, 2005
38,728
0
0
61
I come from a land down under
boat1.JPG
 

wiseco7mgt

dirty mechanic
Aug 12, 2007
811
0
0
queensland
Thanks for some ideas guys,when i said i was after 350hp + i wasn't kidding the wakeboard mostly likes speeds around 35klmh to 50 klm as any faster you lose the fat wake and start to break bits off your body when you constantly crash after being inverted.
I skiied behind a 350 chevy ski boat and its speed and torque was great for what im after, and lets face it they would be lucky to have 250 hp.
I looked at getting a similar engine to Ian as they are so cheap for what you get but its a little over the top for what i need it to do.
The boat will mostly be used in a freshwater lake but after a full day of skiing anyway it will be washed out and lubed up for next time. I don't expect the heads to last all that long with corrosian but at least 7m heads are cheap enough to replace every season.
The turbo should be fine and if i make a scoop for the motor i can have it getting its air from up out of the spray so i can't see it much different to a car, although ive noticed most turbo boats don't run a air filter, suppose dust is a non issue.lol
 

Poodles

I play with fire
Jul 22, 2006
16,757
0
0
42
Fort Worth, TX
Honestly I'd run a heat exchanger instead of messing with the head every season.

Head work on a 24 valve head is NOT cheap...
 

wiseco7mgt

dirty mechanic
Aug 12, 2007
811
0
0
queensland
Poodles;1325815 said:
Honestly I'd run a heat exchanger instead of messing with the head every season.

Head work on a 24 valve head is NOT cheap...

Yes it is cheap, i can just use cressida mx83 heads which over here are a dime a dozen. I've never paid more than $100 for good one.
If you lap all the valves your self and fit your own valve stem seals its a very affordable job.