Photo Archive
Building: Haynes roadster on the road since november 2014 bu
posted on 15/4/20 at 09:31 PM
Flaming engine
Hi,
First I hope everyone is safe and healthy, and that you don’t get too bored despite the lock-down. Here in France we are in the same situation, and we
just learnt yesterday that the lock-down is extended for 4 more weeks, until May 11th...
Could you please watch this short video I made today, and if you have a good experience with engines, tell me if I should worry about the flames going
out from the exhaust ports.
Is it supposed to be like that because there is no exhaust manifold installed to hide the flames, or are these flames totally abnormal and should I
worry?
The engine is a bike engine from a Kawasaki GPZ550 (ZX550) Unitrack for 1984. It is 100 % stock, and running the OEM constant depression carburettors.
Ignition is electronic managed by a small ECU.
I completely renovated the engine, dismantled it completely, change every part that needed to be changed (oil seals, bearing, pistons, piston rings,
valves, o-rings, gaskets, completely refurbished the carbs, adjust the valve clearance, and so on...) I reassembled it following scrupulously the
instructions of the Haynes service and repair manual, and adjusted the cam timing accordingly.
I was very glad that the engine started straightly, from the first try (the video doesn't show the first start, but the third or fourth, so it
was already warm. For a more complete video from the first start, please watch this one:
https://youtu.be/PtSWGLxIivg).
I think the engine seems to run very well, take the revs correctly, no lean cylinder for what I can sea, feel and hear.
But this is my first engine rebuilt. As it started straightly, and seems to run correctly, I think I haven’t done a complete mess of it, so I’m pretty
happy, but I just want to make sure that everything looks and sounds OK to the eyes of more experienced engine rebuilders on here, and that small
flames going out of the exhaust ports are totally normal.
I watched the vid and then read are the flames normal.. That did make me laugh
Those flames are small... I miss the old days when flames poured out the side pipes and burnt all the wadding from the silencer. You need more unburnt
fuel!
Photo Archive
Building: My car is history now, burnt out,
posted on 16/4/20 at 07:47 AM
I do believe ALL petrol engines produce some form of flame at the ports, as the fuel is still burning as it gets ejected out
My best memory of this was a friends e-type 4.2 that I helped (spanner monkey) rebuild when I was about 15
once the engine was in and ready, but no headers or exhaust at this point, he fired it up, the sound was amazing, and even
on tickover, the flames were about a foot long
And did I mention the sound !! it was like an aircraft engine
steve
Thats was probably spelt wrong, or had some grammer, that the "grammer police have to have a moan at
Photo Archive
Building: Haynes roadster on the road since november 2014 bu
posted on 16/4/20 at 08:45 AM
Hi,
Thank you very much for all your answers, very helpful. I'm totally reassured now, and I can put the engine aside for now and start renovate the
rest of the motorbike.
quote:Originally posted by gremlin1234
I have not watched it -yet, but what fuel are you using? I guess in france it's e10?
Yes, spot on that is exactly what it is
quote:Originally posted by ReMan
Perfectly normal..
Well done rebuilding it, though it sounds expensive, was it worn out?
The gearbox part was in perfect shape, I changed some bearings by security but some were still in good condition. The problem is I don't know
the history of the motorbike, I don't even know how many km it has run, so better to be safe. Same for the clutch, good conditions and discs
thicknesses within the tolerances.
The engine part was not in a good shape. Valves were damaged (I made a post here about
that the some months ago) and needed to be replaced, pistons had small cracks between the piston rings slots, and needed to be replaced too, as
well as all the piston rings. Alternator rotor was completely corroded, and went into an electrolyse bath, and is fine now. I needed to repair a few
threads with helicoils here and there. The electric loom was looking very old and crappy, but it turned out that everything is working fine (relays,
converters, IC ignitor, coils, etc.)
Appart from that, all engine casings have been cleaned, sandblasted and repainted (both DIY). Motor has been reassembled with stainless steel screws
and bolts. So yes, it was a bit expensive, because motorbike parts are insanely expensive, when you find them! But it is part of a bigger project, to
make a Café Racer of the old GPZ550, and hopefully a good looking one . For more details, here is a link yo my build blog (it has a google translate
widget): https://cafrazx550.blogspot.com/
Again, thank you all for having put my mind at ease
I suppose if you have never run an engine without headers on it looks a bit wild but as the exhaust valve opens before the piston has reached tdc
it's still burning. On some engines you can actually see a bit into the engine as a ring of light round the valve. Just watch your eyebrows
Mostly a nice blue flame so the mixture looks to be good
Sylvain - this has just given me a massive boost in motivation to get my Pinto to the same point. Can't wait to see flames spitting out the
side. I'm imagining it will be like a scaled down version of this (skip to 1:58 for the action)....
Petrol engines certainly emit flames from the exhaust ports. Obviously with a manifold and exhaust system fitted you don't see them. Starting
an engine without manifold and exhaust mean you'll see them. People can get caught out / burnt as can bits of vehicle if you start the engine
fitted in the vehicle.
Take care, stay safe and stay the right side of the engine
