85hp V4 Mod begins

[spybot]

This thread has sort of encompassed all of my winter projects but to bring this back on track.
My 85 to 140 mod is in the beginning but i have put a dead line on it.
I must have the engine stripped and rebuilt by the 1st of Feb.
Here is a wee recap on what i want to do plus a few extra bits of info.
I want to turn my 1980 Johnson 85 into a 140 but a decent 140.
I know i have machining to get done (bottom rib removed, ports widened to 140 and block milled for filler plates) I also need two cylinders to be re bored to 2nd over size.
Now i have this work to be done on a budget. Its a real tight budget.
I have all the parts to make the mod, High comp heads 1 5/16th carbs, intake and exhaust stuffers.
I have purchased a job lot of wise pistons so will be using these, Santa brought me a set of Carson reeds.
I have a 21" prop from a friend,
The motor i want to build is for play more than race so 6500rpm will be my goal.
Already port flowed the intake and the carbs. I will port match/flow every part of the build. The rods and pistons will be balanced.
The ignition system is CD2 i cant afford to up grade to CD4
What else can i do to help the engine stay strong at 6500rpm ?
The boat is a sidewinder copy at 16ft and 660lbs
Guys i dont have a shed load of money to dump im to this, in fact i had to save all year for the parts i have.
Plus i stay in Bonnie Scotland so there are not many spares to be had.
Any and all help welcome
Cheers Andy

[FMP]

Where's the floor of the ex ports in reference to the piston crown at BDC on these V4s?

[spybot]

This thread is now closed.
I am selling my 85hp so anyone in the UK looking for a good rebuilt V4 85hp let me know.
I will start a new thread as i have got my hands on a 1979 115hp
This should be turned into a 140 very easily.
Thanks for all the input and be sure to follow my new thread" Modding a Johnson V4 115hp into a 140
Cheers Andy

[racervboat]

Put the bubble back exhaust on the 115 and the tighter heads and you have a 140hp.

[spybot]

Put the bubble back exhaust on the 115 and the tighter heads and you have a 140hp.

Bonus it has a bubble
I have the stuffers for the reeds and a set of 1 5/16th carbs to go on plus the H/C heads.
I will do a bit of port flowing ? Is that the correct wording i mean its only smoothing the air flow from the carbs till the hit the reeds.
It has a choke but i will be changing that to the primer system. Shooting the fuel mixture direct into the bypass cover.
It will take a wee bit of work but think i can get to 140 in no time.
I get the engine on Thursday the 1st ironically the date i wanted the 85 project completed.
When the heads are off i will strip it down tackle squaring the ports and get it honed as i have a new set of wiseco pistons sitting .
Think i will need to pick your brain regarding jetting plus a lot of other things.
Maybe get it done a 2 weeks ????
Any ideas or things i should not do ?????
Andy

[olboatman]

Bonus it has a bubble
I have the stuffers for the reeds and a set of 1 5/16th carbs to go on plus the H/C heads.
I will do a bit of port flowing ? Is that the correct wording i mean its only smoothing the air flow from the carbs till the hit the reeds.
It has a choke but i will be changing that to the primer system. Shooting the fuel mixture direct into the bypass cover.
It will take a wee bit of work but think i can get to 140 in no time.
I get the engine on Thursday the 1st ironically the date i wanted the 85 project completed.
When the heads are off i will strip it down tackle squaring the ports and get it honed as i have a new set of wiseco pistons sitting .
Think i will need to pick your brain regarding jetting plus a lot of other things.
Maybe get it done a 2 weeks ????
Any ideas or things i should not do ?????
Andy

Yes Andy I have an idea of what you should do....Ship it to racervboat!!! lol Just kiddin as I'm sure Ken will steer you in the correct direction.
Gary

[spybot]

If i could i would in a heartbeat.
I will have get my advice long distance
Andy

[racervboat]

the 115 is basically a 140,its got the bubble back and 140 ports already and should have 1 5/16 th carbs if it does not have the high comp heads swap them out and you have a 140 .

[phillnjack]

friend of mine is going to be making the tuners for these, the proper ones as fitted to the 1977 140 ( the real 140 crossflow).

dont know a price for them yet though.