SS1 1800 CVH Project update still misfire

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myredscimitar
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SS1 1800 CVH Project running but bad misfire

Post by myredscimitar » Fri Aug 14, 2020 8:39 pm

If you think most water is out it could be worth trying something like this

https://www.ebay.co.uk/itm/2-x-WYNNS-DR ... ect=mobile

Seemed to work for me a few years ago.

Quick, cheap and easier than taking the tank out. Not a lot lost if it doesn't do the job.


1600 CVH SS1 1988
1400 CVH SS1 1987
Previous GTE 6b 1983
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Peter S
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SS1 1800 CVH Project running but bad misfire

Post by Peter S » Mon Oct 12, 2020 11:25 am

First you can drain water from the fuel tank without taking it out you "just" take out the boot liner and the fuel gauge sender and then pump it out. It actually only took 40 minutes as only recently but the boot liner back. Took another 5 litres+ out. :oops: It then took over 2 days for the remaining water to drain to the pick up point. I guess it seeped under the baffle plates there was refstill about 1/2 litre or more.
All back together and running still with a misfire so for all the engine guru's out there any ideas :?:

It's worse when cold with the engine shaking about once warm it's better it runs for a few seconds cleanly then misfires a few times the runs ok for a few more seconds.
I've replaced dizzy cap (including having to drill out one of the fixing screws so that aM6 bolt will fit in the tapped hole in the dizzy - as the old cap :!: )
Now plugs, leads and rotor arm and plugs slightly closed up. All of which made very little difference. Plugs were a little sooty but not run under load. No backfires or pinking, starts OK timing correct, when really warm ticks over just about OK (at least I know the cooling fan works) but still missing at higher revs but it feels like an Italian turn up may work but engine should be run in. :w
I'm at a loss :!:

Also not sure of compression ratio. Are the 1600 and 1800 pistons the same :?: I guess they kept the 1800 ones (same bore as 1600) I understand the stroke is 8 mm more but the block is 10mm higher so with 1600 head and similar pistons and the block not skimmed this would give only about 8.5 :!:

In other news I've got the LHS headlight working the copper strip in the gearbox assembly was not making contact I'd cleaned up (original problem) tested it while horizontal then cleaned again and mounted - vertically and not making contact :oops: The lights still come on before lights rotate and having just checked this the light no longer retracts :!:

This car does not want to go back on the road :!:


Peter S
I'm back - with a SS1 1800? project

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philhoward
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SS1 1800 CVH Project update still misfire

Post by philhoward » Mon Oct 12, 2020 11:47 am

Peter S wrote:
Mon Oct 12, 2020 11:25 am
Also not sure of compression ratio. Are the 1600 and 1800 pistons the same
I think not - and the conrods are also different between 1600 and 1800.

1600 (early) pistons have a hump on them, late (lean burn) and turbo have flat top pistons. 1800 ones are flat top.
1800 bottom end and hemi (early 81SM and EFi) head gives you abour 8.2 to 8.5:1 CR (I have an engine built to this, but was for turbocharging). I didn't calculate a lean burn (86SM) head CR.

That's what I understand anyway...

What does a compression test say? I had a partial misfire on one cylinder on one of mine - turned out to be a lazy tappet partially compressing (so I only got half the valve lift). New (to the engine...) tappet and all 4 cylinders fired perfectly again.


Phil Howard
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reliant-reviver
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SS1 1800 CVH Project update still misfire

Post by reliant-reviver » Mon Oct 12, 2020 1:00 pm

Not quite Phil.
Hemi have a double crowned piston.
Lean burn have a sloped crown piston.
RS Turbo are flat top.
1800 CVH are ever so slightly dished - HOWEVER overall crown height above gudgeon may be higher than RST - that bit I can't recall.


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philhoward
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SS1 1800 CVH Project update still misfire

Post by philhoward » Mon Oct 12, 2020 1:11 pm

Happily corrected.

The dish on an 1800 piston must be very slight as I don't recall it; I think (and it might be detail differences elsewhere unrelated to the reciprocating components) there are 2 different 1800 engines just to mix it up.

TDC had the piston crown level with the block as I recall - same as an RST one?

I used to have in my head crown heights - I think the gudgeon pin is the same diameter although the crank end is certainly different.


Phil Howard
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Peter S
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SS1 1800 CVH Project update still misfire

Post by Peter S » Mon Oct 12, 2020 6:42 pm

Thanks all
Phil H good shout about with the lazy tappet that makes sense the engine has been standing for a long time
I thought the pistons were flat topped not domed they are not new so likely to be standard 1769 (with a slight dish? and new rings)
I will try and borrow a compression gauge as don't have one at least it may give a clue about the compression ratio

Also read that one of the 1800 engines was non interference which maybe handy :!:


Peter S
I'm back - with a SS1 1800? project

Scim8tar
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SS1 1800 CVH Project update still misfire

Post by Scim8tar » Wed Oct 14, 2020 9:31 pm

Peter S wrote:
Thu Aug 13, 2020 7:13 pm
I thought the electronic ignition would either work or not.
The electronic ignition can misfire, one cause is a bad earth between the amplifier and dizzy, other fault's in the amp's vari-dwell function could cause strange misfire's but you need a scope to test it, and on the CVH as far as Bosch or Lucas in Ford applications you can't test the pulse generator separately.

Paul



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SS1 1800 CVH Project update still misfire

Post by Peter S » Tue Oct 20, 2020 5:54 pm

Further update Re Headlight lift motors.
Finally ( on the 5? attempt) I've finally managed to get the LHS Lift motor to work in both directions! ( It worked either up or down not both)
For future reference it was the switch contacts in the gearbox - the copper strip. When checking off the car you need to have the crank arm attached to the drive spindle.
If not the drive cog tends to move closer to the plastic pins that brake the circuit by lifting the copper strip so it tests OK but once installed with the crank arm attached this pulls the cog away from the pins and the circuit may not make or brake. Once clean I had to bend the copper strip so that each end went up and down breaking and making the circuit when activated by the plastic.

In other news it did managed to borrow a compression gauge ( which had no glass In front of the gauge and was rusty!) All cylinders read about the same only 80 psi!!
But I think each time I run the engine the misfire is not so bad - possibly wishful thinking certainly tick over OK when hot. Going with lazy tappets I'll run it some more to see if they get better.


Peter S
I'm back - with a SS1 1800? project

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Old and Slow
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SS1 1800 CVH Project update still misfire

Post by Old and Slow » Tue Oct 20, 2020 7:23 pm

Sounds like the compression gauge only gives "relative" pressure and not absolute, and as they all read the same, nothing to worry about (he says, fingers crossed!) :?


Philip Needham
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philhoward
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SS1 1800 CVH Project update still misfire

Post by philhoward » Tue Oct 20, 2020 10:32 pm

Old and Slow wrote:
Tue Oct 20, 2020 7:23 pm
Sounds like the compression gauge only gives "relative" pressure and not absolute, and as they all read the same, nothing to worry about (he says, fingers crossed!) :?
“for indication only” as we used to say when it didn’t have a valid calibration :mrgreen:

Even is good.


Phil Howard
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