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gears
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Joined: October 28, 2002
Posts: 4391
Location: Tamarack, Bend, Kailua
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 Posted: Tue Jul 16, 2013 6:40 am Post subject: |
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No need to "clear out fins" .. just carefully machine through them.
Required tooling:
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aka Pablo, Geary
9.36 @ 146 in '86 Hot & Sticky
'90 Syncro Westy SVX
'87 Syncro GL 2.5
https://guardtransaxle.com |
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Steve Arndt
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Joined: August 01, 2005
Posts: 1780
Location: Boise, Idaho
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| Posted: Tue Jul 16, 2013 1:22 pm Post subject: |
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049
http://revmasterautomotive.com/revmasteraviation/?p=125
These REV049 proprietary cylinder heads are heavy-duty, thick-wall casting designed for large displacement engines, with 40mm intake valves and 35.5mm exhaust valves, and machined for dual plug ignition application.
Pair REV049 cylinder heads, complete with stainless steel valves, springs and retainers $895.00
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gears
Samba Member
Joined: October 28, 2002
Posts: 4391
Location: Tamarack, Bend, Kailua
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| Posted: Tue Jul 16, 2013 3:20 pm Post subject: |
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For high performance, aiming toward the exhaust (on all cylinders) with small plugs is the least disruptive to intake flow.
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aka Pablo, Geary
9.36 @ 146 in '86 Hot & Sticky
'90 Syncro Westy SVX
'87 Syncro GL 2.5
https://guardtransaxle.com |
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Juanito84
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Joined: March 17, 2012
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Location: Colorado Mountains
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| Posted: Tue Jul 16, 2013 4:24 pm Post subject: |
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How are you supposed to get a tight quench with the revemaster heads if the plug comes out in the quench area?
Looks like machining your own would be better. However I'm sure it would be easy to mess up a head if you're not experienced at machining. Guess I better find someone who is.
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If a water cooled engine cools its water with air, isn't it just an overcomplicated air cooled engine? |
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gears
Samba Member
Joined: October 28, 2002
Posts: 4391
Location: Tamarack, Bend, Kailua
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| Posted: Tue Jul 16, 2013 5:06 pm Post subject: |
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I was wondering the same thing. Looks like "divot pistons required".
Anyhow, if you look at the two "pattern" heads in my previous photo, you'll see the optimum placement for 10mm lower plugs, allowing max valve size and max flycut without the plug getting in the way of anything .. and both plugs pointed toward exhaust valves. Oh .. one big one .. you can easily change the plugs!
For big valves, the upper plug would typically be moved outward slightly, reducing size from 14mm to 12mm.
_________________
aka Pablo, Geary
9.36 @ 146 in '86 Hot & Sticky
'90 Syncro Westy SVX
'87 Syncro GL 2.5
https://guardtransaxle.com |
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drumbum68
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Joined: October 15, 2010
Posts: 566
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| Posted: Wed Jul 17, 2013 5:51 am Post subject: |
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| The 049 dual plug heads look hemi cut to me. |
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Jimmy111
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Joined: October 05, 2006
Posts: 2643
Location: Wyoming
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| Posted: Wed Jul 17, 2013 9:27 am Post subject: |
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| Yes, they look hemi cut. |
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mark tucker
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Joined: April 08, 2009
Posts: 23937
Location: SHALIMAR ,FLORIDA
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| Posted: Wed Jul 17, 2013 9:43 am Post subject: |
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| ditto. |
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Steve Arndt
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Joined: August 01, 2005
Posts: 1780
Location: Boise, Idaho
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| Posted: Wed Jul 17, 2013 11:52 am Post subject: |
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http://revmasterautomotive.com/revmasteraviation/?p=308
quote:
Revmaster Aviation has finished development of its latest upgraded engine, and the results are in: more horsepower at any usable rpm. The new Revmaster R-2300 (2331cc, 142.2 cu.in.) engine maintains Revmaster’s famous proprietary systems and parts, including its RM-049 heads that feature large fins and a hemispherical combustion chamber; and it maintains the earlier R-2200’s engine’s top horsepower (82) at 2950rpm continuous. (Takeoff power is rated at 85, at 3350rpm.) |
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gears
Samba Member
Joined: October 28, 2002
Posts: 4391
Location: Tamarack, Bend, Kailua
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| Posted: Wed Jul 24, 2013 8:43 am Post subject: |
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My first dual ignition engine back in the '80s utilized Epco aircraft heads into which we installed larger seats and hemi cut the chambers. I didn't much care for the entry angle of the plugs, though ..
_________________
aka Pablo, Geary
9.36 @ 146 in '86 Hot & Sticky
'90 Syncro Westy SVX
'87 Syncro GL 2.5
https://guardtransaxle.com |
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HansMartin
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Joined: January 21, 2009
Posts: 34
Location: Bergen, Norway
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| Posted: Sat Aug 31, 2013 4:03 pm Post subject: |
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Got this in a trade - think the valves are 32 and 40 , anyways they are twin spark.
Was planning to run dual coils triggered from the dizzy as per usual - but after reading in this thread this seems to the wrong way to do it . I'll read it all one more time and see if i understand more second time around  |
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Bashr52
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Joined: July 16, 2006
Posts: 5666
Location: On an island in VA
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| Posted: Sat Aug 31, 2013 6:35 pm Post subject: |
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| HansMartin wrote: |
Got this in a trade - think the valves are 32 and 40 , anyways they are twin spark.
Was planning to run dual coils triggered from the dizzy as per usual - but after reading in this thread this seems to the wrong way to do it . I'll read it all one more time and see if i understand more second time around |
Those heads would be killer on big cam small bore engine. You could run some crazy compression with no ill effects.
My thought on a dual plug setup would be to run two of the compufire D.I.S. style systems. I think Jake Raby tried that setup though and found it had an issue. |
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HansMartin
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Joined: January 21, 2009
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Location: Bergen, Norway
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| Posted: Sun Sep 01, 2013 8:49 am Post subject: |
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trying to read up on the ignition system for the Alfa Romeo 8v engines - they use twin spark and the coils fire two sparks at the same time for each cylinder.
THis is all new territory to me thou - so i'm reading and reading trying to understand how things are supposed to work |
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Juanito84
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Joined: March 17, 2012
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Location: Colorado Mountains
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| Posted: Sun Sep 01, 2013 8:09 pm Post subject: |
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| HansMartin wrote: |
trying to read up on the ignition system for the Alfa Romeo 8v engines - they use twin spark and the coils fire two sparks at the same time for each cylinder.
THis is all new territory to me thou - so i'm reading and reading trying to understand how things are supposed to work |
The idea is about speeding up the flame. Slow flames rob the engine of efficiency and power. This is because a slow burning flame must be started sooner (more advance) and so creates more back pressure durring the compression cycle. It also continues burning a longer time after the piston is on it's way back down causing full potential pressure to not be reached until late and therefore is a power loss during the begining of the combustion cycle when you could have had full pressure.
Theoretically it would be most efficient for all the fuel to burn instintaneously at TDC. But we don't have the technology to do that. We can, however, speed up the flame by 1) increasing compression, 2) enrichening the fuel mixture, or placing a rich patch of air/fuel by the sparkplug (aka stratospheric charge), 3) creating more turbulence like with quench, 4) creating more load by using a smaller displacement or taller gears, 5) making smaller compact combustion chambers instead of long flat ones so that he flame has less distance to travel, 6) centraly locating the sparkplug so the flame has less distance to travel, or even better, 7) increasing the number of sparkplugs per cylinder so the flames have less distance to travel.
It becomes obvious that two flames started at two different spots will burn up all the fuel faster than just one flame. Of course you have to adjust the timing (retard it) because things will burn up faster. But now you'll have less back pressure during the end of the compression cycle and more down pressure durring the begining of the combustion cycle. These both translate into more efficiency and therefore better fuel mileage and power.
Then again you also have the aviation standpoint where you need a second ignition system in case the other one fails since there aren't very many places to pull over an airplane with a dead engine.
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If a water cooled engine cools its water with air, isn't it just an overcomplicated air cooled engine?
Last edited by Juanito84 on Mon Sep 02, 2013 3:58 pm; edited 2 times in total |
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HansMartin
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Joined: January 21, 2009
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Location: Bergen, Norway
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| Posted: Mon Sep 02, 2013 12:34 am Post subject: |
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| very nice clarification for a novice like me thanks . |
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-Alex77-
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Joined: December 09, 2008
Posts: 513
Location: Finland
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| Posted: Mon Sep 02, 2013 2:48 am Post subject: |
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Thorsten Pieper billet heads
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Lasercut parts and CAD design |
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58 Plastic Tub
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Joined: September 03, 2007
Posts: 418
Location: Nowhere, USA
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| Posted: Mon Sep 02, 2013 9:13 am Post subject: |
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| -Alex77- wrote: |
Thorsten Pieper billet heads
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Where does one obtain these heads? Please don't say "from Thorsten Pieper"-- I'm looking for contact information.
Thanks!
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Stan Galat
"Everybody is entitled to their own opinions, but not their own facts." |
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-Alex77-
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Juanito84
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Joined: March 17, 2012
Posts: 2436
Location: Colorado Mountains
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| Posted: Mon Sep 02, 2013 4:01 pm Post subject: |
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 Wow! Billet dual ignition heads!
Too bad I don't have €1800. 
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If a water cooled engine cools its water with air, isn't it just an overcomplicated air cooled engine? |
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Jake Raby
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Joined: August 23, 2003
Posts: 7433
Location: Aircooled Heaven USA
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| Posted: Mon Sep 02, 2013 4:35 pm Post subject: |
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People who favor conventional tuning and engine design simply cannot wrap their head around twin plug engines, their combinations and optimum tuning. When they try, they often fail. Instead of altering the combo they generally just say "it doesn't work" and then slam the technology.
It took us over a decade to come up with the optimum combinations. These are dramatically different than their single plug counterparts. I start at 11.25:1 CR with any twin plug engine.
In 2014 all of my engines will be twin plugged as standard offerings.
I love my 993 twin plug, vario-ram, daily driver!
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Jake Raby
Raby Engine Development
www.rabyenginedevelopment.com
"I've never given anyone Hell, I just told them the truth and they thought it was Hell" |
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