Author Topic: Gonzo's ThunderDrum  (Read 724 times)

Offline Froudy

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Re: Gonzo's ThunderDrum
« Reply #15 on: April 29, 2017, 11:41:58 PM »
Good news that the head wasn't cracked mate :D
Assumption is the mother of all Fuckups

Offline user name

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Re: Gonzo's ThunderDrum
« Reply #16 on: May 01, 2017, 09:49:51 AM »
you're a tit !
whiskey throttle with a dash of premature acceleration

Offline Gonzo

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Re: Gonzo's ThunderDrum
« Reply #17 on: May 02, 2017, 09:11:05 AM »
Only one picture update this time, as I got waaaay into it and wasn't stopping for anything.

Yesterday saw the top end go back on... twice...
Got a bit carried away with the lapping of head to barrel and ended up with some serious piston/head contact when turning it over by hand. This picture was taken the first time the head was torqued down...

After stripping it all off again, the addition of a second base gasket seems to have done the trick (lack of any resistance when hand-cranking with the decomp. lever engaged, and again on the starter would suggest all is well, anyway...) and I'm back to where I was in this picture., albeit with the wiring a bit neater and the CDI finally in place.

Still To Do:
-File holes in cam cover backplate oval to allow for the 1.2mm-odd drop in head/barrel height
-Reassemble cam drive with new belt
-Fit exhaust
-Upload new ignition map with less advance to stop any detonation issues
-Hope and pray that she fires and doesn't attempt to self-destruct.
-Dance around with joy/throw tools around and scream in despair as necessary.
I hate oil-boilers.:mad1:

Offline Gonzo

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Re: Gonzo's ThunderDrum
« Reply #18 on: May 10, 2017, 08:33:24 AM »
So last... Wednesday, I believe, and last night saw some more spannering. Wednesday, got the cam drive all together, ran the starter cables through the engine and up the subframe rather than up and over the engine along the frame spine, and some other tittivation. Had it running, but it was making the most horrendous din so I swiftly killed it and gave it up as a bad idea. Put it all away and went back inside rather annoyed.

After some pondering and discussion with Kyle for a few days, decided it may be valve clearances, so had another go at everything last night... The result was a little more involved than planned...
I hate oil-boilers.:mad1:

Offline Gonzo

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Re: Gonzo's ThunderDrum
« Reply #19 on: May 10, 2017, 08:38:39 AM »
More pics from Weds. (1st pic) and last night to give a vague idea of progression, then regression, then progression again.

Started with the valve clearances, ran it up again, no difference. Fuck. Took pic for posterity, to show where I'd got up to before pulling everything apart AGAIN and discovering something unpleasant...
I hate oil-boilers.:mad1:

Offline Gonzo

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Re: Gonzo's ThunderDrum
« Reply #20 on: May 10, 2017, 08:45:17 AM »
After pulling the head off for the 3rd time (needless to say, I'm getting pretty fucking quick at pulling this engine apart...) I was greeted by a most unpleasant sight. The piston had been smacking the head. On the upside, the contact was incredibly limited and relatively light, so I got away without any major repercussions.

Pulled the barrel (again...) and added base gasket number 3. Yes, 3 base gaskets. That'll give you a clue as to how OTT I went on the lapping of head to barrel.
I hate oil-boilers.:mad1:

Offline Gonzo

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Re: Gonzo's ThunderDrum
« Reply #21 on: May 10, 2017, 11:46:45 AM »
On the insertion of said gasket, I then had the unending fun of refitting the barrel. Again. You'll read that word a lot. I fucking hate this job. Rings 1 & 2 are no issue. Do them with my eyes closed. The oil ring, however, is a cunt and I detest it. No ring compressor, so had to use the old ziptie trick, which is still fiddly as fuck.

Head went back on, obviously, the rest was a bit of a blur of spannering and swearing in fading light...
I hate oil-boilers.:mad1:

Offline Gonzo

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Re: Gonzo's ThunderDrum
« Reply #22 on: May 10, 2017, 11:51:16 AM »
Last update for now...

FINALLY got it all back together, FINALLY got it running without the din, so can FINALLY breathe a sigh of relief that I shouldn't have to even look at my tools again for anything other than checking valve clearances and re-torquing the head after it's all settled.

...We'll leave out the slight misfire for now. HT lead has probably had it...
I hate oil-boilers.:mad1:

Offline TOAD

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Re: Gonzo's ThunderDrum
« Reply #23 on: May 10, 2017, 05:52:13 PM »
All sounds good then mate
 Its great when a plan comes together

Offline Froudy

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Re: Gonzo's ThunderDrum
« Reply #24 on: May 11, 2017, 06:04:22 PM »
I like a happy ending... 8)
Assumption is the mother of all Fuckups

Offline Gonzo

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Re: Gonzo's ThunderDrum
« Reply #25 on: May 13, 2017, 03:15:17 PM »
And she's all together now. Went out for a test-thrash today, nothing too long-distance for the sake of recovery, and aside from the slight misfire (new HT lead seems to have worked wonders now) and idling issue (worn carb slide, new one to be ordered) she performed absolutely flawlessly!

The porting and 636 kit have really given it some snap, and the torque! Fuck. Me. Any gear, any rev, wind her open and she'll have you really holding on! No hesitation, stuttering, bogging, just brutal acceleration! Kept up with one of those new Golf R's up to 80-odd, and he wasn't hanging about!

I'M SO FUCKING HAPPY I COULD SHIT!
I hate oil-boilers.:mad1:

Offline pete1234

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Re: Gonzo's ThunderDrum
« Reply #26 on: May 13, 2017, 05:30:03 PM »
sounds like you deserve to buy yourself a pint or 2 reckon you've done a good job but 3 base gaskets in my book is just plain feckin greedy  ;)
proud to be a pork eating kafir

Offline Froudy

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Re: Gonzo's ThunderDrum
« Reply #27 on: May 13, 2017, 06:26:07 PM »
Well done Gonzo 8)
Assumption is the mother of all Fuckups

Offline Gonzo

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Re: Gonzo's ThunderDrum
« Reply #28 on: May 13, 2017, 10:50:37 PM »
Pete, eventual aim is to work out the thickness of 2 of those gaskets, then make a solid copper head gasket of the same thickness instead. As you may or may not know, the Rotax doesn't use a head gasket, it relies on properly-mated surfaces. Which is a bit daft in all honesty.
I hate oil-boilers.:mad1:

Offline Froudy

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Re: Gonzo's ThunderDrum
« Reply #29 on: May 13, 2017, 11:43:23 PM »
Not a lot of people know that Gonzo..Well I didn't :P
Assumption is the mother of all Fuckups