Seeadler18 <marko.rocznik@...>
Yep - it looks like the Q-performance list is dead. I never liked the idea to splitting plan-build and advanced Qs - since almost everybody subscribed to both and it's just more effort to check the two user groups instead of one.
Marko
toggle quoted messageShow quoted text
--- In Q-LIST@yahoogroups.com, Isaksson Roger <scratchdeeper@...> wrote: If you want performance you must have an engine
________________________________ From: Phil Lankford <britmcman@...> To: "Q-LIST@yahoogroups.com" <Q-LIST@yahoogroups.com> Sent: Tue, April 13, 2010 11:43:07 AM Subject: Re: [Q-LIST] Diesel Q1, update, and propeller question.
 Is the Q-Performance List dead? Should I begin to post all my alternate engine and plane mods questions and discussions here on the Q-List?
Phil Lankford
On Apr 13, 2010, at 10:08 AM, Mike Perry <dmperry1012@ att.net> wrote:
Roger:
I think you have two different planes confused. Jon Finley used to fly a Quickie with a VW; he now flies a Q2 with a Subaru and a Paul Lipps prop.
On the three angle valve job and thermal coatings: I'm not sure you get much hp benefit at the rpms we usually run (~3200 in the VW). The thermal coating does make cooling easier (coat the pistons also and the oil runs cooler). The Techline website currently shows a slight decrease in power below ~4500 rpm; when I looked last year they showed a slight increase, but it can't be more than +/- 1-2% at that rpm range. More than 5% is likely in the 6000 rpm range. I can't find a graph right now but memory says most of the benefit from 3 angle valve jobs and other intake mods comes in at 4000 rpm.
More discussion on this probably belongs on the VW list?
Mike
Isaksson Roger wrote:
Hi Jon
Thanks, yes I think I will go the way you suggest, get the IVO on it and get ballpark figures, the Ellipse is definitely an efficient design, and especially as I don't have much of HP in my project to start up with, I am keen to have as efficint prop as ever possible. Once I have my ballpark figure, I can submit it to Paul Lipps. I am a
long way from there though.
One thing you might consider to get more oomp in your engine to get more oomp out of it, but not having to machine work too much, is to do
a small program.
You can let the engine stay in your plane, you only need to take out the top part. ( I am assuming you have a VW) head, cylinders and pistons.
In most VW Hot rod books, there are pictures and diagrams how you can
improve the flow of your head.
If you take a head and hold it in your hand, looking at the combustion
side of your engine, you should se the valve heads, ok there is a wall
on one side that is restricting the flow, radius out that portion, and
you get improved filling of the cylinders.
Do a what is called a three angle valve job, and you will improve flow
also, once the three angle valve job is done, put the valves back into
the seat, and grind them in.
You will have on your valves now a polished grind mark on the contact
face of your valves, it will be a grinded, polished band all around the contact face (again, the roughly 45 deg angle, that contacts the valve seat.)
Most probably you will now find that the the polished surface , is only a small part of the whole contact surface.
The "extra" part is stopping airflow.
This is really easy, you can do all this yourself , get a good ironfile, and a drill with adjustable speed, and a piece of leather.
Wrap a piece of leather around the valvestem, and inser it into the drills chuck, like if you were installing a drill.
Start the drill, you will find out with the variable speed what rpm is
good(, .....it's a feel thing,.... but you will catch on really quick.) and start filing the valve in following fashion.
Look at the edge of the valve face, and you will most probably see some square or sharp profile, if it is a standard out of the box valve.
That edge have to have a radius, a smooth round edge, prefereably all
the way down to the polished valve seat mark.
Ok once that is done, look at the back of the valve, (still the round
flat part, but the side that is facing the stem), from the stem, to the 45 degree cut, you will se that there is a lot of unneccesary material . The original slope down to the 45 degree cut is very shallow, and it's meeting the 45 degree cut with a sharp edge.
File down the back of the valve in such a way that you will get a one
surface funnel all the way to the grinded polished contact surface.
You really don't do too much, just sit there with the drill in your hand, it's doing the job for you.
Ok that is all the machining you need to do, now clean the parts and have them thermal coated.
You can either get a kit yourself, but you get the most consistent result if you send them in to a shop that is doing it.
Coat the inside(compustion chamber) of the head, coat the valves, especially the head, an up through the backside and the stem on the exhaust valve.
Coat the top of the pistons, and have the piston skirts coated at the
same time, with anti friction coating.
Get it back, and put it together, and you will now have an engine that
breaths easier, runs cooler ( the heat is contained better, doing a better job of pushing your prop) and will do more work for you. ( of course, there is also the option of taking the whole engine apart and
have every nock and cranny done per the book, but the pistons, heads and the valves are the important parts)
Typical tests in Hot Rod magazines, shows ( they have done thousands of them by this time) about 5 to 7 % increase in both HP and torque.
So Jon, now you will have an engine that will be more optimized for your prop, and it is not too much of a deal to do all these steps.
Your prop, and engine compatiability solved.
Good luck Jon.
Roger
Reply to sender | Reply to group | Reply via web post | Start a New Topic Messages in this topic (10) RECENT ACTIVITY: New Photos 1 Visit Your Group Quickie Builders Association WEB site http://www.quickiebuilders.org
MARKETPLACE Stay on top of your group activity without leaving the page you're on - Get the Yahoo! Toolbar now.
Welcome to Mom Connection! Share stories, news and more with moms like you.
Hobbies & Activities Zone: Find others who share your passions! Explore new interests.
Switch to: Text-Only, Daily Digest • Unsubscribe • Terms of Use . [Non-text portions of this message have been removed]
[Non-text portions of this message have been removed]
|