dmcgeehon

Dual Overhead Cam 4 Valve Glow or Gas engine!!!!
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Specifications:
30 cc (1.82 cu in)
Bore 1.437
Stroke 1.12
Weight 41 Oz. ( I'm on a diet so i'm still losing) expected production weight 37 - 39 oz.

Some of the features of the engine are:

Overhead cam with bucket in sleeve type valve actuation
Shim under bucket for valve lash adjustment
Long con rod to stroke ratio
Optional adjustable cam pulleys
Hard chrome cylinder sleeve
Three needle carb for precise tunning (carb on prototype's picture not the same a production carb will be)
Belt tension easily adjustable
All bearings made in America or Japan ( 8 total bearings)
Optional gas or alcohol version with electronic spark
Crankshaft and valves have special "Tuftriding" treatment


This is a prototype (1 of 10) that we have been developing for the past one and a half years totally made from barstock, entirely made on CNC equipment for the tightest of tolerances and fits. All materials and alloys selected from experience in material science," no stone left unturned as to: what if....what works best "

These motors were developed to test and to proof out the design, with this phase well under way we are nearing the next phase that will be small scale production for sale to the public.

If you are interested in this engine please leave a responce


Thanks Dan / Precision Plus Engineering

William Robison

My Feedback: (3)

Dan:

Looks like a rework of the [link=http://www.rcuniverse.com/forum/fb.asp?m=2256293]Abitar[/link] or the [link=http://www.rcuniverse.com/forum/fb.asp?m=2274230]Conley[/link] DOHC engines.

How soon do you expect production? Projected price?

Bill.

PS: I'll leave this alone for the moment, but it will be moved to the Product Announcement forum. wr.

Meesh

My Feedback: (135)

I want one! E:mail me at [email protected]

Flyboy Dave

My Feedback: (21)

I'm in for one ! [sm=thumbup.gif]

Edit: I hope it's a non-interference type valve set-up.

Dave.

CAPtain232

My Feedback: (40)

Surely you have test run these prototypes??!!

What sort of performance are you seeing wtih them? RPM with what prop

carlbecker

My Feedback: (3)

I'm interested. Like to have some performance specs. and fuel requirements.

Carl

dmcgeehon

Dave:


No it is not an interference set-up, there is .04 clearance between the valves and their cut-outs in the tops of the pistons.

I also am building twin cylinder 80cc DOHC for Giant Scale Racing (Formula 1) search in forums for "DOHC twin" should bring it up, it was posted by Rcign, Plus there are 60cc twins in the works that should be in test by December

Will post component pictures this week.

Thanks for your interest

Dan

SpyintheSky

dan

What is the performance and dimensions of the engine?

dmcgeehon

Captain232:


This is a version 2 of this engine that has not been tested yet though testing should start in a couple of weeks. All of my testing to date have been on larger 80cc twin DOHC that we have been working on for the past 2 years, these twins have produced astonishing amounts of power and torque once the cam timing, lobe shape, lobe centers, were right we were spinning up a 20 x 20 Chuck Winters props formerly APC's racing prop designs. The engine would turn the prop in the 9000 + RPM range, fuel used was 15% lube 20% nitro the balance methanol. The engine was set up with twin carburators mounted directly on the intake ports the compression was at 9:1 both intake and exaust cams have 302 degrees of duration lobe centers at 100 degrees. According to Thrust HP it works out to 16 - 17 HP, like most rational people I do not believe in the formula it is at best optimisticly overestimated, I have calculated over and over and believe the HP to be 12 + - .5. The testing on the twins has tought us a lot of what mistakes cannot be made and what will work, through this evolution we have came up with the DOHC single over the last 18 months. I could tell you how many hours I've spent in the design stage but you would only ask me why.... it becomes a passion.
I could tell you what I believe the performance will be like but I would rather wait. Did I mention that the motor has a 10:1 C/R


Engine size:

From crankshaft CL to top of valve cover is 5 3/16
Width at valve covers is 2 7/8
Length from prop hub to back of cam belt cover is 5 1/8
Inside width for beam mounts is 1 27/32 (1.844)

We hope to start a small production run of 50 to 200 engines before 1/1/05


Thanks for your interest


Dan

Willdo

Dan,
That's a good looking machine, I hope your efforts bear fruit.

I do appreciate just how much hard work it would have taken to get it this far, - guess it would have other applications too, which would help to make it all worthwhile!

Glad to see someone with a little vision!
Good luck.

dmcgeehon

I have some good news about the 30 cc DOHC single!! Testing has started and I have some results. The engine is still being run very rich approx a gallon of fuel has been used. I started leaning it out some ...... here are the results with a APC 17 x 8 N prop it was steady at 9600 RPM and with 18 x 8 APC it was turning 8700 RPM exaust temp was between 290 - 330 F that temp was taken from the outside of the exaust manifold up as close to the head as possible. These performance values should increase as the carb is leaned and I tweak cam timming and duration currently set at 100 deg lobe centers and 290 deg duration.


Thanks for your interest Dan

bako

oops. thais doch engines perform wonderfull on cars. how will be the price?

Hans Meij

Dan, thanks for the info. The numbers sound good.
Some questions.
Will this engine run well on low or zero nitro.
You mentioned the possiblity for the use of gas. Any performance numbers or guesses yet with gas?

dmcgeehon

Yes the engine will run without nitro, have not tested this yet but from testing I have done on other engines it has worked ok. I will let you know what the performance is this week. I am currently working on an ignition version of this engine.

Thanks Dan

dmcgeehon

The price will be $800.00 to $1000.00 depending on the way the engine is set up. The ignition version will cost somewhere around a thousand +.

I am planning to do some testing in a large helicopter soon so there is the possibility of having a engine that is specific to heli's also.

Thanks Dan

Rudeboy

You mean you wanna rev the crap out of it...?

dmcgeehon

Dave:


Actually I was going to change the cam timing to give it more low end so as to reduce the gear ratio between the rotor and engine to keep the motor limited to the 10,000 RPM level. Today I let the motor unwind a bit with a 16 x 8 APC at 10,400 to 10,600 for a while.... the engine is still not peaking I have been running it rich with 15 % nitro 15% synthetic / caster lube fuel. This week end I will be running it with 30% nitro 17% synthetic lube fuel. Oh you asked if it was an interference engine?

No interference here....... there are valve cut-outs in the piston

Thanks Dan

dmcgeehon

Carl:

I have some performance spec's for the 30 cc DOHC single!! Testing was started a couple of weeks ago, it has had over two gallons of fuel ran through it. The engine is just getting broken in and we are seeing better than expected performance numbers..... here are the results of week one: a APC 17 x 8 N prop it was steady at 9600 RPM and with 18 x 8 APC it was turning 8700 RPM and with a 16 x 8 it was turning 10,300 exhaust temp was between 290 - 330 F that temp was taken from the outside of the exhaust manifold up as close to the head as possible. Yesterday I again tested the 16 x 8 but with a different carb set-up and had it turning 10,750 I also tested it with a 17x 12 and had it at 7,800. I believe that I still have some untapped potential in the engine, I will keep you up to date.

As the numbers show the engine is showing big power with a wide power band.


Thanks for your interest Dan

dmcgeehon

I know its been a while but thought you would like to hear of the results for the running of the engine on ignition also thought you would like a picture of the set up, the carb for the alchol was a Delorto I took off of a OPS 30.... worked ok but the pumper did not work well at high RPM 8500 and above with crankcase presure although we did have it running in 10,000 range for short times. Had better luck with a Walbro that came off of a Zenoah G26 running on gas 25:1 lube with this setup it rubs fine at 9000 RPM with a 16 x 8 APC prop. I will have more numbers and different as soon as possible.


Heree is a picture of the Delorto setup



Dan

dmcgeehon

I thought you would like to see some of the engine development that is happening right now


Dan

PlaneKrazee

My Feedback: (14)

What ever happened to these engines?

MetallicaJunkie

its so sad they never became a reality... beautiful engines!

dmcgeehon

To everyone interested:

These engines are still being worked on (improved on). I have sold some and given some away to close friends. There for a period of time I got so busy with semi-conductor work that I could not devote much time to my engines. That is changing.... as of now I do have some free time. Back in 2005 I designed a 60cc engine that used the same 30cc heads as the single. Since then when I had time I machined the parts it needed, that part was done some time ago and have almost got the first two ready to run. This twin has presurized oiling through the(1) crankshaft (2) oil is then drawn to the camshafts via a displacement pump (3) the oil is recirculated to a oil tank. This is just a simple description of how the oil system works. The purpose of all of this is to create a engine that does not need oil mixed in with the fuel.


Will post some new news and pictures.

Dan

PlaneKrazee

My Feedback: (14)

Pricing?

rcdude7

My Feedback: (264)

Very expensive, no doubt...........


Nothing wrong with that though, I'm sure if he could produce the in the numbers that saito and OS do, he could compete with thier pricing also.