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Diesel Dave
2CV Fan
Joined: October 31st, 2012, 5:31 pm
Posts: 79
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 Compression - I've had better days Just finished futzing with the AK after a couple of days holidaying in the Malvern hills.
The motor just doesn't perform as well as the old Acad.
Checked the timing, spot on.
Check the valve clearances - spot on.
Check the compression... oops, one side 150psi and the other is down to 100, and these are supposed to be 9:1 pistons.
I've re-torqued the head down and now it's up to 125psi
I feeler a tear down is in order, or might just swap to the spare motor.
What would you do - strip the current engine in situ, or swap the motor?
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| October 25th, 2014, 4:06 pm |
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subarupete
Firing on two.
Joined: March 5th, 2009, 6:23 pm
Posts: 2247
Location: Near Monmouth
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Re: Compression - I've had better days My 2psi
Take the head off the low side and clean up the seating of the barrel at both ends.
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| October 25th, 2014, 4:51 pm |
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ken
Agony Aunt - You have a car problem? Speak to Ken
Joined: March 6th, 2009, 1:40 am
Posts: 3675
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Re: Compression - I've had better days The thing is, they're both low for 9.0:1 pistons, which should read more like 175 psi. Engine hot and throttle wide open, of course...  Bottom of the barrel? That sounds a rather novel idea. subarupete wrote: My 2psi
Take the head off the low side and clean up the seating of the barrel at both ends.
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| October 25th, 2014, 7:46 pm |
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Sean
Firing on two.
Joined: April 22nd, 2009, 11:06 pm
Posts: 3684
Location: Ecosse
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Re: Compression - I've had better days tappets can have quite a marked effect so make sure they are OK especially if the head studs have been re done. after that its usually scuffed bores
_________________
Kissing the Lash
"Any advice of a technical nature is given on the understanding that I've actually done this shit, not just read about it in D*lly club mag some time ago.
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| October 25th, 2014, 10:49 pm |
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ayjay
Firing on two.
Joined: April 27th, 2012, 6:48 pm
Posts: 709
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Re: Compression - I've had better days might be a 2 stroke 
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| October 26th, 2014, 3:26 am |
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Diesel Dave
2CV Fan
Joined: October 31st, 2012, 5:31 pm
Posts: 79
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Re: Compression - I've had better days Just taken off the 2nd cylinder head from the spare motor in preparation..... When you find the stud is glued in with firegum...  I've had better days... 
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| November 7th, 2014, 7:19 pm |
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subarupete
Firing on two.
Joined: March 5th, 2009, 6:23 pm
Posts: 2247
Location: Near Monmouth
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Re: Compression - I've had better days That's repairable, get it plug welded (alu). Drill and tap.
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| November 7th, 2014, 7:30 pm |
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Sean
Firing on two.
Joined: April 22nd, 2009, 11:06 pm
Posts: 3684
Location: Ecosse
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Re: Compression - I've had better days bolt and washer for the cheap bodge
_________________
Kissing the Lash
"Any advice of a technical nature is given on the understanding that I've actually done this shit, not just read about it in D*lly club mag some time ago.
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| November 10th, 2014, 9:57 am |
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Diesel Dave
2CV Fan
Joined: October 31st, 2012, 5:31 pm
Posts: 79
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Re: Compression - I've had better days Sean wrote: bolt and washer for the cheap bodge Sean I'm shocked; that level of bodgery shows a lifetime of practice. It's all welded up and all the M7 threads have been helicoiled for a bit of futreproofing. I'll post a piccie when I pick them up on Sat.
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| November 10th, 2014, 11:39 am |
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Diesel Dave
2CV Fan
Joined: October 31st, 2012, 5:31 pm
Posts: 79
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Re: Compression - I've had better days All repaired   Now what's the weather forecast this weekend?
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| November 14th, 2014, 11:32 pm |
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