Fuel/Timing trouble after Head Gasket change?

[Vic Ayres]

Can I have some advice please. Just done head gasket on 72 spitfire mk4. Before strip down I marked all timing marks for tdc. Now back together but no fuel getting to plugs. Have checked & triple checked everything but still will not start. Any ideas?t. Thankyou. Vic.

[Dannyb]

I can't see why the timing should be affected with a head gasket change. Only valve adjustments. 

Danny

[RobPearce]

Have you checked it's got compression? Did you use the right gasket?

As Danny says, there's no reason to disturb the timing for a head gasket change.

[PeteStupps]

Choke and throttle linkages all working ok? Daft question but are your plug leads on in correct order? We've all hashed that up at some point...

When you say no fuel getting through, is that because plugs are dry? If so, pop the fuel line off the front carb and check that some comes out when you spin the engine. Ideally catch it in a jar or something. 

If I can't get an engine to fire normally I spray a bit of Easy Start down the carbs to diagnose whether it's fuel or ignition. 

Did you have the dizzy off? 

[Vic Ayres]

There is fuel going into carbs, leads all on correct and yes to all other suggestions apart from did not remove dizzy. Thanks again.Vic from swindon.

[RobPearce]

31 minutes ago, Vic Ayres said:

yes to all other suggestions

Please be more specific and less dismissive. If you want our help, we're very happy to give it, but you should at least try to give the impression you're paying some attention to it.

So, does that throwaway comment mean you've already tried Pete's suggestion of using EasyStart? If so, what was the result? Can you now clarify whether it's a fuel or ignition issue? Does it mean you've tested the compression? If so, what readings did you get?

[Vic Ayres]

Ah well, more head scratching over this one. Might try reducing tappet gaps to 6 or 7 th/in. Vic.

[Vic Ayres]

Sorry,didn't mean to sound that way. I tried easy start but made no difference.  I will check compression tomorrow evening and let you know the results.  It is just frustrating after trying to work it out for the past 3 days. Once again sorry to come across in a bad way. Vic

[RobPearce]

You shouldn't adjust the tappet gaps away from the correct spec, and certainly not reduce them! Tappet gaps too large just makes noise. Tappet gaps too small can result in loss of compression when hot. Stick to the correct gap.

If the easystart made no difference that strongly suggests it's not a fuel supply issue. That's why Pete suggested the test - an engine that isn't getting any fuel will normally attempt to fire on easystart (but only run until the squirt has dried out). If it doesn't, then something else is preventing it from making use of the fuel that's getting in there.

I'll await the compression results. Given that the head's been off an the dizi hasn't, compression is the top candidate at the moment.

[Vic Ayres]

OK Rob cheers. Whats strange is car was running fine before all this apart from oil leak from rear of head gasket. Will get back to you later . Thankyou. Vic

[Vic Ayres]

Hi all. Unfortunately I am going to have stop work on spitfire till Monday. I will keep you all posted with progress. Thankyou all for your help. Vic

[Vic Ayres]

Hi all, Vic from Swindon. Just spent 2 hours on spitfire again. Compression is between 60/65psi so that sound good for 99000 mile engine. Have good sparks & fuel in carbs. Blooming old cars, who'd have em? Now getting desperate. Would appreciate any help. Cheers

[glang]

Oh dear that sounds very low as you really want more like 140 - 160psi. Are you sure youre getting a proper reading? If so the next step is to repeat the testing after putting a tea spoon or so of engine oil in through each sparkplug hole. Then if readings are still low the problem is with valve or head gasket sealing while a good increase indicates poor sealing piston rings...

[WIMPUS]

Did you fit the right gasket ?

As you have non recessed and recessed.

Dont know if the later mkiv's had a recessed block or not.. 

Whas there a step around the bores ? 

Also.. 

Payen or unbranded gasket ? 

 

[Vic Ayres]

I have recessed block & unbranded recess gasket. Not tried oil trick though so I will try that  also am going to fit new timing chain/sprockets as there seems a lot of movement at pully. Will have to try all this in a couple of weeks cos will be away until after jubilee weekend.  Thanks for all your help . Will keep you posted.Vic. 

[RobPearce]

As glang and Wim said, that's a very poor compression figure and typical of having the wrong gasket fitted. The other possibility (and I'll put my hand up and admit to having done it more than once) is that you didn't clean the block and head faces of all the remnants of the old gasket. Last time I changed a recessed head gasket, I had to take all the studs out and give both faces a go with the scotchbrite disc (the softer brown one, not the vicious black) to get it clean enough.

[Vic Ayres]

I think that might be the next thing I will have to do. I will still fit new timing sprockets & chain cos of the amount of play, will save a job later down the road. I did fit new studs & thought block looked clean but I may of missed something. Thanks for that Rob. 😄. Vic.

[glang]

The chain and sprockets always have quite a bit of play which is taken up by the tensioner. My free to download Vitesse workshop manual says the limit is a 10mm gap between the chain and a straight edge placed across the two sprockets. I wouldnt replace components if unnecessary as you never know what the quality of the new stuff is going to be😬

[Vic Ayres]

Thanks glang. I will check that all bits are not worn too much and check gap. Do you think a new tensioner would be of any benefit.?

[glang]

I think if the tensioner isnt obviously a candidate for changing then it must have been newed at some stage possibly along with the chain and sprockets. Saying that the tensioner isnt anywhere as near long lasting as the other components and you'll see two grooves being worn in it by the chain links. If these are anymore than minor indentations then yes probably worth changing it although again Ive heard of pattern part replacements being all the wrong shape! I wonder that if they cant even get the shape right what chance is there the metal spec is right☹️ 

[Vic Ayres]

This is very true. I will give it a thorough inspection. Cheers

[glang]

You can always put photos on here if you want a selection of additional opinions😁

[Vic Ayres]

Thankyou. I am now on holiday so will not be working on car until after Bank Holidays. Will update as things progress. Cheers. Vic

[Vic Ayres]

I would just like to thank everyone who gave me things to check after my spitfire would not start after head gasket change. After trying everything more than a few times it still would not start. Right I thought, let's start again and when I removed gasket again I found it had not sealed between cylinders 1/2 &3/4. So fitted a payen gasket and it started first time. So once again thanks to you all for all your valued advice it was much appreciated.  Vic.

[yorkshire_spam]

Good news Vic!