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Spitfire & GT6 Forum

Rebuilt head / no compression

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Lizzard d id
san jose, ca, USA   USA
In reply to # 1484922 by colodad
In reply to # 1484912 by Lizzard And if you do them one at a time , front to back without the rule of 9s , you don't have a chance of messing up the rule of 9's .

I put a socket on the crank pulley nut, watch the valve close as I turn the crank, adjust that rocker and go to the next one.
That will work on any motor with any number of cylinders . 1 cylinder or 12 , it gets the job done .

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SpiTazz72 Avatar
SpiTazz72 Bryan H
Magnolia, Texas, USA   USA
In reply to # 1484922 by colodad
In reply to # 1484912 by Lizzard And if you do them one at a time , front to back without the rule of 9s , you don't have a chance of messing up the rule of 9's .

I put a socket on the crank pulley nut, watch the valve close as I turn the crank, adjust that rocker and go to the next one.

This is what I do. Just remember to remove the socket before starting the engine.

Pats54 Avatar
Pats54 Gold Member Mark M
Maynard, Mass, USA   USA
1979 Triumph Spitfire 1500
2012 Volvo C70 "The Weekender"
Bryan
Rather than rolling the car you turn the crank with a socket, I would think this gives you more control when watching the valves open and close. I will see if I have a socket. I think I have up to 1-5/8. Would you know the size?

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Brad.Cogan Avatar
Brad.Cogan Bradley Cogan
RAF Cosford, Shropshire, UK   GBR
1977 Triumph Spitfire 1500 "Wray"
2007 Fiat Grande Punto "Pepper"
Yeah it will most likely be the valve clearances.

Asumming it's had a skim on the head, it's now at a different height and so are your valve clearances.

If the valves are staying a little open during the compression stroke then you'll get very low compression if any.

Just adjust them with a screwdriver, spanners and a feeler gauge.

The only other thing I can think of is the head gasket is buggered



Brad Cogan

1977 Triumph Spitfire 1500 'Wray'
2007 Fiat Grande Punto Active 1.2 'Pepper'

Lizzard d id
san jose, ca, USA   USA
In reply to # 1484994 by Pats54 Bryan
Rather than rolling the car you turn the crank with a socket, I would think this gives you more control when watching the valves open and close. I will see if I have a socket. I think I have up to 1-5/8. Would you know the size?
In neutral with the spark plugs out , you might be able to rotate the crank by hand , or by rotating the generator / alternator .

Doug in Vegas Avatar
Doug in Vegas Douglas D
Las Vegas, Nevada, USA   USA
I printed this and hung it on the wall in the garage.


kaatmanduu Avatar
kaatmanduu Silver Member Mike Stevens
Grass Valley, California, USA   USA
The nut on the crank is a 1 13/16.

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clshore Carter Shore
Beverly Hills, Florida, USA   USA
In reply to # 1485063 by kaatmanduu The nut on the crank is a 1 13/16.

Two cranks sizes, two crank nut sizes ....
(I don't remember the other one)

Qualicum Beach, British Columbia, Canada   CAN
1976 Triumph TR6 "The Truck"
I assume that the cam TIMING is spot on. The rocker arm gap would have to be way off to get those compression results...

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Pats54 Avatar
Pats54 Gold Member Mark M
Maynard, Mass, USA   USA
1979 Triumph Spitfire 1500
2012 Volvo C70 "The Weekender"
Thanks guys for the insight I will mic the cam nut for the size.

Rob I would not assume the timing is spot on. I marked the dizzy and the pedestal when I started this mess
But have been moving back and forth trying to get it to fire.

Thanks for the chart Doug.

ExPatBrit Avatar
ExPatBrit Mike W
Redmond, WA, USA   USA
In reply to # 1485151 by Pats54 Thanks guys for the insight I will mic the cam nut for the size.

Rob I would not assume the timing is spot on. I marked the dizzy and the pedestal when I started this mess
But have been moving back and forth trying to get it to fire.

Thanks for the chart Doug.

I think Rob is talking about camshaft / valve timing, if you didn't remove the timing chain you should be fine.

BTW a sheared crankshaft woodruff key can cause weird compression results.

bonnett1954 Avatar
bonnett1954 Silver Member Dave Bonnett
Las Vegas, NEVADA, USA   USA
1978 Triumph Spitfire 1500 "Union Jack"
In reply to # 1484994 by Pats54 Bryan
Rather than rolling the car you turn the crank with a socket, I would think this gives you more control when watching the valves open and close. I will see if I have a socket. I think I have up to 1-5/8. Would you know the size?

I got a big 18" Crescent wrench that I use for that job. Slower than a socket but very effective, lot's of leverage.

Pats54 Avatar
Pats54 Gold Member Mark M
Maynard, Mass, USA   USA
1979 Triumph Spitfire 1500
2012 Volvo C70 "The Weekender"
Dave yes I guess you are right,
I did not mess with the timing chain.
I guess if the valve adjustment does not work out I can look into that.
But I would not attempt it.

Lizzard d id
san jose, ca, USA   USA
In reply to # 1485175 by Pats54 I guess if the valve adjustment does not work out I can look into that.

How soon might you get to the valve adjustment ?

Brad.Cogan Avatar
Brad.Cogan Bradley Cogan
RAF Cosford, Shropshire, UK   GBR
1977 Triumph Spitfire 1500 "Wray"
2007 Fiat Grande Punto "Pepper"
To adjust the valves, I put the car in top gear, roll it forward and back and when one valve on a cylinder is open, then the other one is completely closed (Eg. If cylinder 1 intake is open then cylinder 1 exhaust valve is definitely closed.)

Then do this for every valve.

Just be careful if you have a mechanical fuel pump as rolling it back and forth will make it pump fuel.



Brad Cogan

1977 Triumph Spitfire 1500 'Wray'
2007 Fiat Grande Punto Active 1.2 'Pepper'

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