Milwaukee Midget

[Milwaukee Midget]

Mark, I had a thought.

If you were to take a highly compressible foam - I'm thinking disposable ear plugs - use the RTV method, and after the 3rd coat, fill the rest of the port with these RTV covered ear plugs, you might be able to maintain the shape and still have enough flexibility to pull the plugs out.

Or have I not had enough coffee yet? 

[Seldom Seen Slim]

" Putting 10 pounds of mud in a 5 pound bag CAN be done - Dolly Parton comes to mind "

You're KIDDING, right?  I've been fooled all of these years?

[Milwaukee Midget]

That's actually her self deprecating description - I want to say it was on a CMA award show a number of years ago during what has since become known as a wardrobe malfunction.

"It takes a lot of money to look this cheap."

[manta22]

DP is a good singer, though. Like Raquel Welch, Dolly Parton doesn't take herself too seriously.

Regards, Neil  Tucson, AZ

[jacksoni]

FB- How about this one? : (this quote from my buddy Darin at RMRE)

"I found the distributor for the mold compound I use. Its been many years since I had to reorder. The shelf life on this stuff is about a year. Its much better than Blue-sil or any other compounds I have ever used. I have molds that are six years old and still hold there shape.

GL-1000

Go to this web site.

http://www.silicones-inc.com/conden.htm "

[Andy Cooke]

This method would probably work for you.    It is however, labor intensive, which is why I did not use it.

http://www.diyporting.com/molds.html

 
Lazyflowmonkey

thanks, that's exactly what I'd recalled

Chris - yep, the 7 is much like the T.  As you suggest it's the inlet that's difficult, they're siamesed and T shaped, no concession to shaping.  The valves are 1", the throats and ports are too big, and everything is kinda squared off.  I put it on my flow bench and compared the results to a standard A series 850 head.  They're pretty much the same to about 4mm lift, then the 7 just stops flowing any more.  No idea why the sports cams have 9.5mm lift, even the standard cam has 6...  I'd be happy to make it flow like an 850

Andy

[fordboy628]

This method would probably work for you.    It is however, labor intensive, which is why I did not use it.

http://www.diyporting.com/molds.html

 
Lazyflowmonkey

thanks, that's exactly what I'd recalled

Chris - yep, the 7 is much like the T.  As you suggest it's the inlet that's difficult, they're siamesed and T shaped, no concession to shaping.  The valves are 1", the throats and ports are too big, and everything is kinda squared off.  I put it on my flow bench and compared the results to a standard A series 850 head.  They're pretty much the same to about 4mm lift, then the 7 just stops flowing any more.  No idea why the sports cams have 9.5mm lift, even the standard cam has 6...  I'd be happy to make it flow like an 850

Andy

Plan on adding a BUNCH of furnace grade epoxy to the ports.    Fill in the dead (to airflow) spots.   This will really help the torque by raising the average gas speed.

http://www.ruffstuff.com/pages/kits.html#epoxy

There are several to choose from at this site.   I've used some with good success.

Start by playing around with some "modeling clay" in the likely looking spots in the ports, fill in the "dead spots".    Try not to go bonkers . . . . . .
Also: If you can fit a larger inlet valve, do so.   Take your avg port "bowl" dia and divide by .85

For example:
1" valve with .875 bowl dia.           .875/.85=1.029 valve    The idea is to give the port some taper or radius in the bowl "beneath" the valve seat.   You might be able to go significantly larger, say 1.125/1.1875/1.25, BUT, you will need to be careful of machining into the water . . . . . . . .

Careful "infilling" might give you significant flow increases at higher lifts.     Also use Vizard's thread on a wire tool, although I'm sure he wasn't the originator of the tool.

You want consistent, laminar flow into the cylinder.
 
Fordboy

[fordboy628]

FB- How about this one? : (this quote from my buddy Darin at RMRE)

"I found the distributor for the mold compound I use. Its been many years since I had to reorder. The shelf life on this stuff is about a year. Its much better than Blue-sil or any other compounds I have ever used. I have molds that are six years old and still hold there shape.

GL-1000

Go to this web site.

http://www.silicones-inc.com/conden.htm "

Thanks.    The blu-sil stuff I've been using supposedly has a Shore hardness of 30.   OK for 1 valve per port, but can be tricky to remove.   I've got molds I cast 20 years ago that are still in fine shape.

I'll check with a tech rep at the company.
 
Fordboy

[fordboy628]

Mark, I had a thought.

If you were to take a highly compressible foam - I'm thinking disposable ear plugs - use the RTV method, and after the 3rd coat, fill the rest of the port with these RTV covered ear plugs, you might be able to maintain the shape and still have enough flexibility to pull the plugs out.

Or have I not had enough coffee yet? 

I dunno.    The trick is going to be flexibility/compressability/hillbillity.    As in hollow.
 
Fordboy

[fordboy628]

" Putting 10 pounds of mud in a 5 pound bag CAN be done - Dolly Parton comes to mind "

You're KIDDING, right?  I've been fooled all of these years?

Uhhhmm, not a plastic sturgeon, er, surgeon, but I'm pretty sure, MUD is not used . . . . . . .

Might be the blu-silicone though   
 
Fordboy

[251ENG]

Hello all

I have herd of heads with material added to the bottom of the ports to form a " ramp " towards the valve and increase the radius in to the valve

[Graham in Aus]

Hi Simon, yes, I think that's what's referred to as improving the short turn radius, if the port is too big, better to fill it in an improve flow velocity and if the radius is then able to be less severe (and less turbulent) on the short turn, all the better!

How did I do Fordboy, am I learning??   

The thread on a stick thing, is this to observe where the flow is going whilst actually on the flow bench, I.E. attached flow is better than detached turbulent flow?

[Koncretekid]

Fordboy and Midget,
I used a silicone, type GI-1110, from "Silicones, Inc., High Point, North Carolina, a couple of years ago.  Greased up the  parts I could reach with Vasoline and spayed PAM into parts I couldn't and got the following results.  I then made up a plaster head, ported the heck out of it, and put it on my crude flow bench for results.  Only problem was that I had lots of plaster to grind into, but there's no aluminum where I wanted to port the real head.  I had the head done by E&V Engineering in Howard City, Michigan, and he welded in an extra couple pounds of aluminum before he started.

[Milwaukee Midget]

Those came out nice, Tom.

Only problem was that I had lots of plaster to grind into, but there's no aluminum where I wanted to port the real head. 

Yup . . .

There have been some tricked out new castings from Europe for the 1275 that maintain the stock ports and spread the valve spacing a tad - I suppose I'd call it a "cheater head" - but I can't justify the cost at this point in the game.

[Milwaukee Midget]

Ooooh - all a tingle.

Valves arrived to day.

Of course, I left 'em at work . . . 

But realistically, other than the crank scraper - which should be done soon - maybe a different cam and a set of gapless rings - this is likely the last of the major parts expenditures for this year.  I've got some machine work in front of me, some body work, dyno time, a new firewall and some assembly. 

I'm torn between a new paint job and going with vinyl wrap.  Wrap limits colors, but it's easily 1/3 the price of paint.

Weather is breaking - we'll be above freezing on Friday.

Forecast is for rain . . .