Sam, I am currently running Great Plains cylinder heads on my Revmaster Engine. For spark plugs I am running the 14mm but Automotive Plugs (Bosch 7904).
http://www.greatplainsas.com/sccylheads.html I also see the note that the Great Plains might be up for sale. So, I would give them a call before pursuing. I am still using the Bendix Dual Mag, but converted the spark wires and plugs to automotive to save money on future plug replacements. The spark plug conversion was done per http://www.g3ignition.com/index.html. I am on my second set of heads, but I also have about 825 hours on my engine. I bought the heads from GP, had them machined for 92mm and I had the dual spark plug option installed (looks like both 10mm or 14mm is an option per the web site). Cost was about $1000 when completed. I do like how the Great Plains folks installs the second set of plugs below without going through the valve cover. It is actually far better than how Revmaster does it with the bottom spark plug access through the valve cover. Sorry, I don't have a spare set laying around. I trashed my old set, they were used up. Thanks, Rob Schmitt KR2S N1852Z www.Robert7721.com -----Original Message----- From: KRnet <krnet-boun...@list.krnet.org> On Behalf Of Samuel Spanovich via KRnet Sent: Sunday, March 31, 2019 3:11 PM To: krnet@list.krnet.org Cc: Samuel Spanovich <spanovich...@gmail.com> Subject: KR> Cylinder Heads Cracked - Best brand - Revmaster 2100d If some of you remember I posted a while ago regarding a "chugging" problem with my Revmaster 2100d ("Calling All Revmaster Owners"). I have been hesitant to report back on here without a clear answer to what was wrong because I didn't want to waste anybody's time posting until I had a definite answer. After several days of troubleshooting, yesterday I finally found my answer: Cracked Cylinder Heads. *Note: I made a crucial mistake in my previous post of not explaining that this problem was "starting" to occur even before I changed my propeller, while still running the Culver 48" (low pitched) propeller. For those of you who suspected too high of an engine load and/or detonation with my new higher pitched Sterba, or advancing the throttle too fast, I greatly appreciate this insight, however this was not the case. I take 100% responsibility for not making this clear in the original post and for that, I do apologize. * Up to this point, the engine would start up normally, taxi, takeoff, cruise, and descend without incident. However after the descent, come time for a T&G or Go Around (basically, running a high power setting), the engine would sputter. Initially this was no more than a nuisance and I just had to go reeeeally easy on the throttle up to full power, but eventually it got so bad that on a legitimate go around (not a practice), I almost didn’t have enough power to safely fly away, regardless of how slow I moved the throttle. Half power was about all I could manage out of the Little Engine That Could. Needless to say, I am no longer flying the bird until I get this problem fixed. I first checked the obvious: spark plugs and magnetos. I pulled out the 10+ year old Champion REL37Bs, and....wow......they were nasty! They 10+ were reported at being cleaned at the last condition inspection, however I honestly couldn't believe they were firing at all. Not only were there carbon deposits EVERYWHERE, but the electrodes were getting the aging "football" shape. I elected not to clean them, and instead ordered 8 brand new plugs. As for the magneto, although old, never overhauled, and original to the engine (per the logbook) the Bendix 3000D fired all eight plugs flawlessly, producing a nice crisp spark. After installing the plugs, the engine initially ran very good and I thought all my problems had been solved. However the very next day, while test running the engine again, the problem returned just on the ground alone! When idling at 1500 rpm, there was no roughness, but when the power was increased to 2000-2500 rpm, the coughing/sputtering/roughness/vibration returned, and the engine was meeting all the symptoms of running on three cylinders. To confirm this, with the cowling still on and the engine idling, I took an infrared thermometer and measured the temperature of the EGT coming out of each exhaust pipe and noticed that front left cylinder was running much cooler than the other three. After some further troubleshooting, it was clear the cylinder had very little compression, so off came the head. As all of you VW operators can imagine (or have experienced)….there was a fairly solid crack in-between the valves, despite being the standard 65HP heads. I have been researching the heck out of new heads, from CB performance, Mofoco, EPI, etc. and have found that there seems to be cooling/cracking issues with just about every single one of them. Because of this, I am having trouble deciding on a set of heads. Revmaster no longer makes the stock 14mm dual heads (to my knowledge), otherwise my decision would already be made. They only offer the REV049 heads, featuring bigger valves and dual 12mm spark plugs. I appreciate that they are trying to create more power, however I am skeptical about running a head with even less area between the valves. Combined with the fact that they are $1000 a pair, and that I would have to buy eight new 12mm plugs (after just buying brand new 14mm plugs), this makes them a turn off for me. So in short, I guess my question(s) are…. 1) What is a good replacement cylinder head? (stock valves and 14mm dual spark plugs if able) 2) What type of heads are you guys running? 3) Does anybody have any stock 14mm/Dual Revmaster heads laying around? If so, I would be more than happy to pay top dollar for one to avoid having to wait several weeks, in addition to having to change spark plug types. One is all I need. I was close to buying a single stock CB head, having it machined for a 90.5/92mm bore and dual plugs and buying four 12mm plugs to go with it. I was about ready to order this afternoon but wanted to post on here first. Mr. Langford, your thread on the various VW heads of your 2180 engine, and their cooling properties was invaluable to me. While I am sorry that your DRD heads did not hold up for more than 50 hours, it prevented me from making the same mistake and ordering from them. I noticed that you were not impressed with the CB heads in terms of cooling, however after researching, they appear to be the least of all evils when compared with other brand names, hence why I was considering purchasing a stock head from them. And to all of you, thank you for taking the time to read this post, and be willing to help. Although fairly new to the game, I am proud to call myself a KR owner (even in times like this), and to also be a part of this community. _______________________________________________ Search the KRnet Archives at https://www.mail-archive.com/krnet@list.krnet.org/. Please see LIST RULES and KRnet info at http://www.krnet.org/info.html. see http://list.krnet.org/mailman/listinfo/krnet_list.krnet.org to change options. To UNsubscribe from KRnet, send a message to krnet-le...@list.krnet.org _______________________________________________ Search the KRnet Archives at https://www.mail-archive.com/krnet@list.krnet.org/. Please see LIST RULES and KRnet info at http://www.krnet.org/info.html. see http://list.krnet.org/mailman/listinfo/krnet_list.krnet.org to change options. To UNsubscribe from KRnet, send a message to krnet-le...@list.krnet.org
