Looper exhaust porting

[phillnjack]

this thread has been an amazing read.
not only the guy doing the work showing good pictures, but the amount of great information from people giving advice to help the captain make
improvements along the way and also stopping him making any major mistakes.
The captain has done a great job and with his pictures has helped me understand a lot more about the finger porting.

Now what happened with the second powerhead ?
did it make the 300hp ?

[rude tim]

I use an adjustable angle head that attaches to the quill on my mill. The block is mounted to the table so cyl is parallel to the quill, the angle head fits into the bore and I then use didgital readout to move the cutter (1/2 inch) into the cyl wall and then the power feed to run the cutter down to preset depths. Once all the stops are set its a matter of moving the head from one cyl to the next. Cuts really clean and even finger ports. Maybe Rudetim will be on and he can tell how clean they come out as he has watched me due several.

Do not use the spring hone on your bores especially with the finger ports. You need a key way hone to properly hone the engine bores.

Al you cheat! Lol. They come out perfect! And no arm pump involved.

[rude tim]

On my motors I go 5/8 wide on the finger ports followed by an 1/8 bur to make the bottom wider. I use a set of devider type of calipers to check the depth. I have had them so thin that after a few hours they start seeping through the block. Easy fix sand to ruff up the block and JB weld fix it right up. All fast blocks have zits made of epoxy on the outside.

[Captain75]

this thread has been an amazing read.
not only the guy doing the work showing good pictures, but the amount of great information from people giving advice to help the captain make
improvements along the way and also stopping him making any major mistakes.
The captain has done a great job and with his pictures has helped me understand a lot more about the finger porting.

Now what happened with the second powerhead ?
did it make the 300hp ?

300hp... Don´t know yet.
I have just started the reassebly of my next PH, based on a -99 Closed deck 3 litre looper. The other 2.7 PH has got its fingerports cut and general port clean up, now resting on a shelf to be sold.

About the 3L closed deck:
The block has been cleaned up from all rough casting and gluelines. Exhaust has been widened and raised to 250 specs, all intake ports has been cleaned up and matched to their sleeves. Angles of main transfers has been adjusted to aim towards the back cylinder wall. Rod slots has been smoothed out w/o removing too much meat...

Last night I finished modifying the pistons by enlargening the F/P windows to match the holes in the cylinder walls, together with a round with some 400grit wet paper to get the "new look".


I will start with pistons and crank tomorrow, however I have descision to make concerning heads and cooling and I would very much like your opinions on the matter.
I have two choices:

#1. Either I run my 2.7 heads, (with added dams?) together with a complete 2.7 cooling system, including the check valve. In this case I think I will leave the idle bleeds open due to boat weight!?
#2. I cut the stock closed deck heads and run the stock cooling system, although I'm a bit unsecure on the routing since the PH is going on an 2.7 adapter. In this case the question is how much should be shaved? 0.100"?, 0.125"? Idle bleed, open or closed?

The motor will be turned about 6500rpm, boat weigh appx 2200lbs, prop will probably a Raker 22". Fuel used is equivalent to US 91oct.

Some pics:



Best regards, Anders

[baja200merk]

Run the 2.7 heads

[Captain75]

Some pics of the modified and refinished pistons. F/P holes enlarged and angled to match the sleeves.
Intresting to see how much the locator pins differs in mounting depth... Some of them close to the the piston surface and some much deeper. Is this common?

[FMP]

for the hand held viewers

[racer]

Personally if you have pins that are not all the same on used pistons of unknown hours I would replace them.

[faztbullet]

:iagree Different heights.....tick....tick...tick . Plug them idle reliefs and you'll get about another 8psi....

[Captain75]

I see what you guys are saying and I greatly respect your knowledge, thats why I brought the issue up. However I don´t feel that worried, mainly because I don´t use my boat in the same manner as many people on this board. What do I mean by that? Well my motor is seldom pushed at WOT for more than 15-20 seconds, so I don´t think I (hope:-) that it is able to reach the piston temperature where the pins can start to get loose!? My boat and motor is more of a sleeper, usually used at cruising speed (3800-4000rpms) with some shorter bursts up to 6000+ rpms.
Heating the pistons in the owen an tapping the locator pins with a small pen hammer and something to reach them with, is that something you could do to make sure that they are in the right place? Hell, I have even moved locator pins on small displacement high revving bikes, just drilled new holes and pushed them in there, never looked back...
After reading your replies, I examined the pistons again. 5 of them are fairly the same, whereas nr 6 has got its upper pin furher into the groove.

[Captain75]

Hello again!
It seems one piston has been replaced so I will leave that subject for a while and move on to a different area, cooling.

Haven´t yet decided on how to cool this motor, despite reading everything a could find on this board.

Either a comlpete 2.7 system, including stock t-stats and controll valve (conected to the throttle linkage) or the stock closed deck cooling system i which case I must take the t-stat sleeves from the closed deck heads and install in my 2.7 heads!? In either case I´ve understood that the block needs to be drilled and tapped on the highest spot on each bank in order to prevent airpockets!?

What do you guys think? I have the parts to do both systems.
Can anyone give me a picture explaining the stock closed deck coolsystem hose routing?
Doesn´t the closed deck have a pisser?

I still have everything apart on the bench awaiting reasembly, so I could make bigger cooling mods if that is needed, problem is I need detailed info on how to do it and it seems hard to find.

Looking forward to your thoughts and ideas

Best regards, Anders

[Captain75]

Hello again!
It seems one piston has been replaced so I will leave that subject for a while and move on to a different area, cooling.

Haven´t yet decided on how to cool this motor, despite reading everything a could find on this board.

Either a comlpete 2.7 system, including stock t-stats and controll valve (conected to the throttle linkage) or the stock closed deck cooling system i which case I must take the t-stat sleeves from the closed deck heads and install in my 2.7 heads!? In either case I´ve understood that the block needs to be drilled and tapped on the highest spot on each bank in order to prevent airpockets!?

What do you guys think? I have the parts to do both systems.
Can anyone give me a picture explaining the stock closed deck coolsystem hose routing?
Doesn´t the closed deck have a pisser?

I still have everything apart on the bench awaiting reasembly, so I could make bigger cooling mods if that is needed, problem is I need detailed info on how to do it and it seems hard to find.

Looking forward to your thoughts and ideas

Best regards, Anders

To the Top!

[powerabout]

There are other modifications to make to the 3.0 to stop the cold water going straight to the bottom cylinders I think?

[Captain75]

Just put this block out for sale here in Sweden...

2.7liter, all ports and rodslots cleaned up.

[phillnjack]

great thread keep it up