OS v spec

[dibles]

Hi,

I have just read a thred which is similar to what im going to write but it was quite old so decided to start another,

Been using a OS v spec and the engine has done around 4 meetings. Been using Byron 30% nitro. Engine has been running great except had real problems recently with engine cutting out and not running right at all.

The car unfortunatly saw some wet weather at a previous meeting so im guessin that didnt help! But after the wet race i flushed fuel through the engine, changed the plug and ensured it was running properly before i put it up until the next race. At the last race the problems started, cutting out at slow speed. I changed the plug and still ended up playing with the carb just to try and keep the thing running which it did thankfully (just) But not running right at all even when changing the glow plug.
After getting it home and starting to clean the car i had the engine out and with the flywheel in hand the engine under its own weight just rolled over as if there was hardly any compression (with glo plug installed). When the engine was new it was almost impossible to turn so thought it a real suprise when it just floppped round like a dead thing! When turning the engine over by hand and looking into the exhaust port i can see bubbles of oil/fuel as the piston compresses.

I just read an old thred which says that os engines run loose like a wizards sleeve when they are at there best so maybe its ok?

Does it sound like the engines ####, would i be wasting my time with it any further? is it worth repairing if i can, or do i just need to shell out another 200 quid!
 

[the donkey]

you dont have to get a new engine sounds like it may just need a pinch  there are plenty of people that do this just ask if you want some names to talk to

much cheaper than a new engine 

[Adrian E]

As Glen said, a pinch will restore some of your lost compression provided the piston and liner haven't been damaged (look for evidence of marks on the side of the piston and down the liner and check how far the piston will go up the liner without being forced)

I've just had a pair of OS Speeds overhauled - one was 3 years old, the other only about 9 months.  The older engine had clearly swallowed some water as the main bearing had water marks on it and wasn't rotating freely.  The newer motor had over-revved at Neobuggy and had run the bearing cage very close to destruction.

Basically, before getting it pinched be sure that it doesn't need any other work doing as well.  With the V-spec it pays to check the crank pin hasn't ovalled before you spend any money.

[dibles]

Thanks alot for the help guys much appriciated!!

Firstly the pin hasnt ovaled round so thats the 1st positive,

The piston and liner have no visible marks so that too is positive!

Regarding the point at which the piston pinches at its strongest point, it appears to be pretty much at the blackish line it has created when at TDC. (The blackish line nothing more than left over residue from combustion.)


Im assuming at this point this is also positive!?

I have done a little research on this pinching thing......  From what i have read its a case of getting a small jubullee clip and tightening it up around the liner with the piston in it until it feels tight then heating it on the stove and dunking it it cold water!!!??? Sounds rather crude! Is this right or are there proper tools for the job! Im not gonna pay for someone to do that, i would much rather bodge it myself!! lol

If someone does do all this with proper tools how much am i looking at for this and to replace the bearings just to be on the safe side too? Could you provide names and numbers as i would like to get it up and running aagain asap. I looked online for new piston and liner and its like rocking horse ****. Only place i found it was 80 squids on fleebay coming from Tiwain or some other far away land that will take half the remaining season to blo**y get here!
For some reason it seems os spares are not as widely availiable as other engine manufactorers.

Just another quick question a go engine is around the 150 pounds mark, 120 if you go with the cheaper one. Would these engines be as good as the os with regard to performnance or are they cheap for a reason? Its just if the cost to fix the os is going to near the 80 pound mark for peace of mind i would prefer a new engine. would the pinch fix last that long or is it just a short term fix?

Thanks again for you feedback guys, much appriciated, i look forward to hear what you think

[Adrian E]

Doing a pinch properly involves some proper tools which squeeze the liner evenly - most of the skill is in knowing how much force to use so you don't end up with an egg shaped liner!

There's a few people on Maxbashing that do this - Mallet and Fastboy being 2 I can think of off the top of my head.  Their details are in the homegrown rc business section on there.

I get my engines stripped and rebuilt by Alan Dell, who is usually found at tracks around the South East e.g. Slough, Clanfield, Herts.  He charges £10 to complete a detailed report on the condition of the engine - that includes a strip down, clean, proper measure up of all wearing parts and reassembly.  Depending on what he finds, you can source the necessary parts to rectify any problems and Alan will fit them within that £10 cost, or decide it's uneconomic.  Alan will take the bearings apart and inspect the races and balls for signs of damage - I've been amazed how much a duff track on an outer race will destroy the way an engine runs, long before it's bad enough for the bearing to disintegrate and take out the rest of the engine.

On your last point, I'm not a great fan of the stock v-spec as the crank isn't coated so you usually can't rebuild economically unless you have better spares.  They are generally use and throw away, although Alan does keep a lot of used parts for them and can usually find something better than what you have, if it's needed.  Speeds can be rebuilt at least once without issues as the crank is up to it.  Something like the Go or Alpha engines are a great alternative if you want throwaway engines.

[dibles]

Thanks alot for the advice, im gonna do what i can with it!!

Unfortunatly im not going to get round to getting a replacement engine in time for my next race so what ever i can do with it will be it! It doesnt help im on holiday so i will have 2 or 3 days to muck about with it! Oh well if it last a few heats its better than nothing!!

Im only thinking of the Alpha and Go as they are only cheap! the os hasnt proved to be much cop really so it doest inspire me to spend more than £200 really. Other than the Go and Alpha for less than 200 what would you suggest? At least with the money saved on the go and Alpha i could spend this on tyres or other bits and bobs! I was looking at the RB engine then found out its french!!! I cant stand french, anything french is generally pants!! Maybe another type of fuel!! I have ran the os with 30% byron and since been told its s**t! Im probbly gonna run 25% with the new engine and put a bit less stress on it! I cant see it making much of a difference!!

Let me know your thoughts its much appriciated!!

[Jaf]

We should be there for the next round, so...If you can't get an engine sorted for the next round and are going to be running the V-Spec, feel free to pop over and we'll try and take a look at it with you to see if we can it tuned etc... just make sure the clutch etc is fine and isn't dragging etc beforehand.

Worst case, I have a few used/spare engines and you can borrow one for the day...

[dibles]

Nice one, that would be great!!

Im the geek with the cube and the gazeebo that takes 1/2 an hour to put up!! £25 Asda Bargain!!

Been playing with it today, it runs which is a start, at least i put it back together....... properly ish i hope!!
I think the carb settings are the problem, i reset them to stock but doesnt run right there so im just gonna try and fiddle until it does ish! It starts up ok and at top end seems fine its just the low end that the problem it barbles and the revs fluctuate as if one minite its rich the next lean!? V strange! It also just seems to cut out as and when it wants!? Im warming it up but not letting it get hot and making sure its not running lean. I sealed the carb down, sealed the back plate and removed and cleaned the carb needles. who knows?! Do these little engines play around like this when they ####!? Its so much easier with an old zenoah!! As i said its gonna need replacing so it just need to get it to last the next meeting! I shall see how i get on and your offer of assistance will be mucho appriciated!!

[Jaf]

No problem....look out for the green Landrover!

[Bren]

dibles

Just seen your posts, Pinching gets some life back in the engine but is not really needed on the vspec or speed as the os engines runs on very low if not no pinch. The less pinch you have the greater the fuel economy is so dont be to concerned.
The reason for your tickover or idle dropping out & difficulty in tuning is the main bearing is worn or leaking. get this replaced & it will be good as new.
Like its been mentioned Allan Dell is your man but if its for this weekend you have run out of time as running an engine with a duff bearing will screw your engines life span. Another option if you can get hold of a bearing i have the tools bring it over first thing sunday before you start on your not so easy up & will replace it for you.
Cant miss me in the Xray real easy up.