turbo.gst

My Feedback: (8)

That is an awesome project! Congratulations for a job well done. Thanks for sharing.....

Giant_Scale_Gasser

My Feedback: (84)

Nitromethane actully burns slower, not faster than other fuels, such as gasoline or straight methanol.

This readily seen and heard in Nitro FunnyCars and TopFuel Dragsters. Those nitro burners run in the neighborhood of 60 degrees of ignition lead and the tremendous noise is produced (as are the 5 foot tall flames) because the nitro burns so slowly it is still "firing" down into the header and out the pipes.

The higher the nitro content, the relative slower the flame front travels in the combustion chamber.

SrTelemaster150

That's good to hear.

If I am interpreting this correctly, higher nitro content will be less prone to detonation W/timed spark ignition & tolerate as well as benefit from more ingnition timing advance, not less.

As long as the advance settings @ idle/low RPM don't get to a point that degrades "drivavbility" as far as ease of handling, I can crank as much timing in as needed to extract more HP. If I need more total advance to satisfy high RPM power production as well as low RPM manners, I can get Adrian to cook up a bigger, better advance curve.

Since I am looking for more TQ & don't plan to spin much over 9000 RPM anyway, detonation pulling the cylinder from the (somewhat) overstressed modified case was my main concern.

I don't see making so much pull on the cylinder base bolts that the the case will fail as long as the engine is making power & staying under 10,000 RPM W/O detonation. The rotating assembly should handle anything that 30% nitro will throw @ it as long as the engine is prop loaded to keep revs in line & detonation is not present.

captinjohn

I agree with you about the funny cars....but I am saying if you add say 20%-30% nitro to your fuel a (say) 10 oz tank will not fly your airplane as long in time duration as fuel with no or 5% nitro in it. In other words...if you got 15 min with a 10 oz tank...then added nitro ...the 10 oz tank will not fly your airplane 15 min. It will be more like only 12 min of flying time. You will use more fuel. I know I have noticed it many moons ago. Capt,n

captinjohn

<hr />Could I use just a nipple at the cam housing and install a small inline check valve in the line? I have the parts and the hole in the cam housing would not need to be as big. Just thinking!!!! Thanks Capt,n PS...does this check valve let pulses out so oil flows in the cam are better?

SrTelemaster150

Yes you can do that. I think I mentioned that option in my post.

I just happened to have the Saito "pump" check valves on hand. Somehow I ended up W/spares from my FA300TTDP.

Regardless of whether you use a nipple W/an inline check or the srew in check valve as I did, they are both 5mm X .8 thread.

The check valve allows an outgoing pulse as you surmised & a surprizing amount of oil dribbles out of the line. I thnk it will add greataly to cam lobe & tappet life. Many of Saito's new high case "B" engine designs have the breather located in the side of the cam case or in the forward portion of the case between the front & rear bearings.



You still want to utilize the rear breather nipple W/a short piece of tubing to allow the case to breath..

SrTelemaster150

There is no free lunch.

The high nitro content makes more power by burning more fuel, hence the higher fuel consumpsion.

I am just experimenting to see how much TQ/power I can extract from this engine. I'm not looking for 10000 RPM but a good moderate RPM range W/a high pitch aerobatic type prop.

If I can surpass 3.5HP by a significant margine I will stop there. I'm already making almost 3.4 HP, another .2 HP or so would be a nice benchmark. (8600 RPM W/an 18X8 prop?) I still doubt that even W/30% nitro that the fuel consumpsion would be anywhere near as much as an FA220 on glow ignition W/15% nitro.

I want some on demand power for my 73" WS Cap 232 for short bursts of impressive vertcal performance.

captinjohn

My thought is with spark ignition the engine will run better and be better on fuel. The big thing is no more kick -back from glow ignition when starting. It makes for a lot more fun experience ! A win-win deal ! Capt,n

SrTelemaster150

Yes you will gain all of those advantages.

I am soon going to have all of my Saitos running on spark. It is sooo much more "user friendly" & eventually CDI ignitions pay for themselves W/about 25% better fuel economy and/or cheaper 0% nitro fuel savings.

blw

My Feedback: (3)

Nitro burns hydrogen after the oxygen is used up. You can see it burning hydrogen along with raw nitro out the exhaust during night qualifying. Awesome. Real engines burn 90% nitro

Giant_Scale_Gasser

My Feedback: (84)

Yes, what you are saying should prove correct. Nitromethane will be consumed at a higher rate than methanol as if I recall, it's Stiochiometric Air-fuel Ratio is approx 2.5:1 versus methanol being approx 6.5:1. On paper, you will burn more nitromethane as you would methanol for a given quantity of air. So the higher content of nitro in a given capacity (10oz tank as you described) will likely yield less run time, however it will provide more power during that shorter run time.

Giant_Scale_Gasser

My Feedback: (84)

Just remember, for dyno numbers or "Paper Power" you can usually show higher numbers on a nitro engine by loading it harder. What I mean is, if you are showing 3.4HP with a 18x8 prop, try a 18x10 or a 20x8 and see what you can achieve. I would assume (I know!) you would see the same increase on a model engine.

D_wilbur

My Feedback: (8)

Earlier in this post someone mentioned installing ignition on a 450R3. I have a 450R3 and would be interested in adding ignition. Is C&H back up and running with a new owner.

SrTelemaster150

C&H Ignitions is looking for a 3 cylinder radial to use for R&D on a single module/single Hall sensor ignition system that utilizes 4 magnets to sequence the spark.

If you are interested in sending them your engine contact Adrian @ C&H Ignitions.

The contact information is on [link=http://ch-ignitions.com/]THE C&H WEBSITE[/link]

D_wilbur

My Feedback: (8)

Thanks for the info.

captinjohn

Now that 3 cyl ignition project sounds neat. Keep me filled in. Thanks Capt,n

SrTelemaster150

Actually he will be able to apply the same technology to 5 or more cylinders in a radial configuration.

C&H will be looking for examples of those for more R&D. An ASP 400R5 would be another example that they would like to work with.

SrTelemaster150

Moved

captinjohn

Would this work? Install a nipple in gear cover and run a line to the exhaust valve cover...then with another nipple in that cover....run a line too the Intake valve cover. Last a 2nd nipple in the Intake cover too a in-line check valve. Seems like it should pulse oil through gear cover...then throughexhaust valve cover and last through intake valve cover. That would lube every part.....I think???? Capt,n

SrTelemaster150

Yes, W/the addition of the inlet check in the crankcase for positive pressure, I've envisioned the same system, but my FA300TTDP W/both an inlet check in the crankcase & an outlet check in the nose between the cams seems to get plenty of oil to the rockers.


I think of you have the engine mounted horizontal or inverted, getting oil to the cam case will take care of the rockers.

If the engine was converted to gas W/the lower oil volume, I think the full oiling system would be an asset. I just don't think it's neccessary W/the high volume of oil we get from burning more fuel W/a higher oil content that glow fuel delivers.

BTW: Go back to my previous post & view the picture I added of the inlet check valve I installed in the backplate of the FA180HC. Soon, once I get a regulator fabricated for fuel pumping it will be an FA180HCP. (high compression pumped)

captinjohn

SR Telemaster 150, thanks for all the good ideas. Best Regards, Capt,n

SrTelemaster150

If you are intent on the full oiling scenerio, I had an idea that would simplify the whole plumbing system. I was considering it myself.

Use an inlet check on the back cover as before. Istead of exhausting the crank case pressure/oil @ the cam housing, groove the tappet bushing @ either the front or rear (away from any side thrust loading) to allow the pressure/oil to easily travel up the pushrod tubes to the rockers.

Then, simply istall a nipple in each rocker cover, run the tubes to a "T" fitting & then run it all through an inline check valve. You can afix the outlet @ the end of the exhust pipe to pull away the oil in the exhaust stream.

I think this mod would be especially advantagious for a gas burner or E-85 use W/the lowered oil volumes & higher operating temperatures

1QwkSport2.5r

I've been reading this thread with interest. With the talk of check valves, extra nipple fittings, extra lines, etc. for better oiling, it sure is sounding like the engine compartment would be rather "busy" and untidy. The nipples in the valve covers would really be unsettling to me, even though the intent for them is sound. I'll be curious to see if all this plumbing gets installed on the engine, what the final product will look like.

Kudos, SrT, on a very ambitious project. Not something I would ever try to construct, so bravo on a working model!

SrTelemaster150

I do have the check valve & tube on the cam housing. Since the rear breather tube is elinated by the intake check,



there is no net increase in the # of tubes in the engine compartment.

Likewise, the routing of the case pressure up the pushrod tubes only requires a breather nipple in each rocker box W/2 very short tubes to the "T" of better yet "Y" fitting W/1 tube routed from there. Not a lot of added plumbing as most of the routing is internally accomplished within the engine.

I have no intention to add the rocker oiling system, but I will run the pressure line from the cam case to a bleed off regulator for pumping fuel from a tank located centered on the CG. The FA300TDP uses just such a sytem as does the FA220 W/the optional "large carburetor".

Since a muffler pressure tap is also eliminated in this scenerio, there is not a substantial increase in plumbing other than the added regulator W/bleed off line..

Agreed, running lines from the cam case to the rockers, then out would be a bowl of spaghetti. I would not ever consider that. The other examples are not as complicated as they seem. No more so than some of the YS fuel systems I have seen.

If someone would donate a spare pair of 120-180 rocker covers to add breather nipples to, I would explore that option as a working model.

captinjohn

I like the Idea of more lube going up the push rod tubes. It would be neat too see photos how that is done. Thanks Capt,n