Author Topic: Timing chain chapter 3  (Read 454 times)

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Offline JNS

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Timing chain chapter 3
« on: Saturday,April 10, 2021, 12:10:01 PM »
I removed the old Timing chain and installed the new one. I cant make ends meet. 120 links, Its short by around 1.5 cms. I counted the links on the old one and it has 122.
SJ sportscars sell one with 122 links for a 711M Tall Block. I can only assume this is what I have.
 Can anyone tell me what it is, and why does my engine have one?

Offline jbcollier

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Re: Timing chain chapter 3
« Reply #1 on: Saturday,April 10, 2021, 02:37:25 PM »
Did you back off the chain adjuster all the way?

Sounds like you have a 1700 cc engine.

Offline EuropaTC

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Re: Timing chain chapter 3
« Reply #2 on: Saturday,April 10, 2021, 10:19:54 PM »
If you have a tall block engine then it means that instead of the Ford 1500/Lotus cast iron engine block someone has used a 1600 crossflow block which is slightly taller to give a bigger cylinder capacity. It's about 1/2" taller from memory and although the head will bolt on as normal, the Lotus front cover and backing plate which holds the water pump will now be 1/2" short. In the past you would add a spacer to the top of the cover between the cover & head (I think that was where it went) and so if you have a tall block then you should be able to identify it very easily by looking for the spacer underneath the head.

If there's no sign of a spacer it might be just that the chain hasn't properly engaged on either the crank of jackshaft sprockets. First option is to fully slacken the adjuster and move the chain to see if it improves. If no improvement and you've set the cams at TDC on the timing marks I would be tempted to remove the inlet sprocket which will  give you a much better view of what's happening where the chain loops over the jackshaft (original Ford cam driving the distributor) and the adjuster.  A USB borescope on a laptop/tablet or phone is a big help here.

Brian

Offline buzzer

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Re: Timing chain chapter 3
« Reply #3 on: Monday,April 12, 2021, 12:32:09 AM »
Also check the block casting number if it says 711 its a tall block and 1600 or even 1700 (1690) if its bored 90+ which is a common mod.
Dave,

Other cars. Westfield SEiW. BMW E90 Alpina D3. BMW 325 E30 convertible and Range Rover CSK

Offline JNS

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Re: Timing chain chapter 3
« Reply #4 on: Monday,April 12, 2021, 12:50:08 PM »
Thanks everyone.
 There does seem to be a spacer in the timing chest and today I found 711M 60158(4?) cast into the block. Is there any way I can find out the capacity of the engine.
Looking back at my notes I once recorded the bore at 83mm.
Be interesting to know.

Offline JNS

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Re: Timing chain chapter 3
« Reply #5 on: Monday,April 12, 2021, 01:12:04 PM »
a quick internet search revealed the numbers are probably 711M 6012 BA The 1600 block
A quick calculation at 83mm bore and 77.62 stroke gives around 1638cc.
(I'm gonna need a bigger chain)