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#11
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Hey Corky,
What was your beef with the 13B? I have to replace a car coming off lease in the next few months and I'm seriously looking at older RX-7s just to get a flavor for the power plant. I like the idea of a no-seize failure mode and the idea of it being 2 co-axial engines in one. The higher fuel burn I can deal with, especially since its mogas. Regards (Corky Scott) wrote in message ... I thought I'd bring everyone up to date. It's true that I had basically given up on using an auto conversion as I was having trouble justifying the cost of the PSRU. I'd started with a Buick/Olds 215 cid aluminum block V-8 and then switched to the Mazda 13B. I disliked all the problems associated with the 13B so I sold that too. |
#12
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John Thompson wrote in message ...
Corky, I think one of the biggest roadblocks in autoconversions is the lack of "cookbooks". Instructions that cover things like that "stud stretching" tip, why you might want to use this camshaft, or replace this part or other, lifter bearing replacement, etc. and where to get them. SNIP John Amen to that, but what scares me about auto conversions is the that the design parameters for the auto engine are based on 25-30% constant power at hiway cruise. The reliability of the engine in automotive use is therefore not a meaningful indication of fitness for flight. Even with the engine blueprinted and a beefed up cooling system and oil cooler added, when you run that engine at constant 75-80% power in an aircraft you are likely to have 'hot spots` in there somewhere which can play hell with reliability. Do a lot of base testing Corky, and good luck to ya. |
#14
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There is nothing wrong with the Mazda engine. All of the earlier problems
have been dealt with effectively and you are likely to see more and more installations as the word gets out that the Mazda DOESN'T use excessive fuel or burn up properly designed exhaust systems. But it is loud and most builders seem to eventually opt for a muffler of some kind. Pound for pound here is no higher horse power output in a normally aspirated auto conversion than that of the Mazda Wankel. Bruce A. Frank, Editor "Ford 3.8/4.2L Engine and V-6 STOL Homebuilt Aircraft Newsletter" | Publishing interesting material | on all aspects of alternative | engines and homebuilt aircraft. "Jay" wrote in message om... Hey Corky, What was your beef with the 13B? I have to replace a car coming off lease in the next few months and I'm seriously looking at older RX-7s just to get a flavor for the power plant. I like the idea of a no-seize failure mode and the idea of it being 2 co-axial engines in one. The higher fuel burn I can deal with, especially since its mogas. Regards (Corky Scott) wrote in message ... I thought I'd bring everyone up to date. It's true that I had basically given up on using an auto conversion as I was having trouble justifying the cost of the PSRU. I'd started with a Buick/Olds 215 cid aluminum block V-8 and then switched to the Mazda 13B. I disliked all the problems associated with the 13B so I sold that too. |
#15
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In article
, BRUCE FRANK wrote: Automotive durability tests exceed, by about 400%, anything required to certify an aviation type engine. (both in hours and precentage of power output) -- Bruce A. Frank, Editor "Ford 3.8/4.2L Engine and V-6 STOL I am happy to concede that some automotive engines may have undergone durability testing that is more severe than that required for aviation engines. However, it is overstating the case significantly to say that these automotive engine tests exceed by 400% the power output required for the aviation engine tests. The aviation engine tests have many sections at 100% power. If you exceed that by 400% you have to run at 500% power. It doesn't help your credibility to state "facts" that are obviously wrong. Type a bit slower next time. -- Kevin Horton - RV-8 Ottawa, Canada http://go.phpwebhosting.com/~khorton/rv8/ |
#16
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I just had the head gaskets in my Windstars 3.8 replaced last year.
about 115K miles at that time, I think. John |
#17
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On Fri, 25 Jul 2003 11:05:21 GMT, Kevin Horton
wrote: In article , BRUCE FRANK wrote: Automotive durability tests exceed, by about 400%, anything required to certify an aviation type engine. (both in hours and precentage of power output) -- Bruce A. Frank, Editor "Ford 3.8/4.2L Engine and V-6 STOL I am happy to concede that some automotive engines may have undergone durability testing that is more severe than that required for aviation engines. However, it is overstating the case significantly to say that these automotive engine tests exceed by 400% the power output required for the aviation engine tests. The aviation engine tests have many sections at 100% power. If you exceed that by 400% you have to run at 500% power. It doesn't help your credibility to state "facts" that are obviously wrong. Type a bit slower next time. -- Kevin Horton - RV-8 Ottawa, Canada Kevin, you have to read what Bruce said carefully. He said that the **DURABILITY TESTS** "exceed, by about 400", anything required to certify an aviation type engine." He did not say anything about exceeding the 100% power tests for aircraft certification. Looks like it's time for me to re-post that article from an automotive engineer about the typical engine development durability tests. I'll post it in a seperate article so as not to muck up this thread. Corky Scott http://go.phpwebhosting.com/~khorton/rv8/ |
#18
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#19
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On Fri, 25 Jul 2003 09:12:08 -0400, "Larry Smith"
wrote: "Corky Scott" wrote in message ... On Thu, 24 Jul 2003 02:33:33 GMT, clare @ snyder.on .ca wrote: [...]they will hold constant pressure. They were suggesting I use the old head gaskets for the initial startup as it really didn't matter what you used. Cardboard would work (they said) since you are just running it to temperature then shutting it down again. Of course, I did not save the original gaskets when I dismantled the two engines so I'll have to buy an extra two. Just another one of those tricks to remember when building engines. I'm sure Lycoming and Continental engine rebuilders have their own tricks. For heads? Most aircraft engine heads screw onto the cylinders with an interference fit. The process is always done at the factory or repair station. And plenty of heat is required. I didn't mean for heads specifically, just building the engine in general. There are always some things you learn after building a few that work well for that engine. When I was a mechanic, I ended up sort of specializing in Subaru's and found out early on that Subaru engines had this hidden bolt that held a part of the two block halve's together. It wasn't a big bolt and one wonders why it was necessary at all, but there it was. It was always hidden by encrusted oil and dirt and you literally had to dig it out so you could get a socket on it. Couldn't split the block halves without first removing that bolt. Personally, I'm fascinated with your use of the Ford V-6 and commend you on it. I wouldn't want to fly one here in the mountains, but where there are plenty of fields to put down in, I'd make a go of it. Good slow stall speed, halon fire extinguisher, and shoulder belts would be a must too. Would you be interested to know that there are hundreds of this engine flying and that many have accumulated significant hours of operation. At least one ran to beyond 2000 hour before the owner/builder did a preemptive teardown for inspection. He found little wear in the engine and the belt drive showed no discernable wear either. He did replace the drive belt anyway though. Corky Scott |
#20
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In article , Corky Scott
wrote: On Fri, 25 Jul 2003 11:05:21 GMT, Kevin Horton wrote: In article , BRUCE FRANK wrote: Automotive durability tests exceed, by about 400%, anything required to certify an aviation type engine. (both in hours and precentage of power output) -- Bruce A. Frank, Editor "Ford 3.8/4.2L Engine and V-6 STOL I am happy to concede that some automotive engines may have undergone durability testing that is more severe than that required for aviation engines. However, it is overstating the case significantly to say that these automotive engine tests exceed by 400% the power output required for the aviation engine tests. The aviation engine tests have many sections at 100% power. If you exceed that by 400% you have to run at 500% power. It doesn't help your credibility to state "facts" that are obviously wrong. Type a bit slower next time. -- Kevin Horton - RV-8 Ottawa, Canada Kevin, you have to read what Bruce said carefully. He said that the **DURABILITY TESTS** "exceed, by about 400", anything required to certify an aviation type engine." He did not say anything about exceeding the 100% power tests for aircraft certification. Looks like it's time for me to re-post that article from an automotive engineer about the typical engine development durability tests. I'll post it in a seperate article so as not to muck up this thread. Corky Scott http://go.phpwebhosting.com/~khorton/rv8/ You've got me really confused now. I thought that when he said "both in hours and precentage of power output" he meant that the 400% claim applied to percent power as well as to hours. If he didn't mean that, what was the "... and precentage of power output" statement referring to? I assume that Bruce simply didn't proof read closely enough. If he in fact meant what he said, I can't understand how it is supposed to be interpreted differently than I have discussed here. FAR 33.49 Endurance Tests requires specified times at specified power levels, including quite a few periods at 100% power. The automotive durability tests have long periods at 100% power. Thus the power levels are the same. There is a big difference in the amount of time at 100% power though, I am not arguing with you on that issue. -- Kevin Horton - RV-8 Ottawa, Canada http://go.phpwebhosting.com/~khorton/rv8/ |
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