DIY HEAD GASKET REPLACEMENT
Discussion
Job's finished at last. These are my observations....
Put aside at least 7 full days
If you are going to do the job properly and renovate as you go along then I would recommend you remove the engine. I probably wasted 3 days just moving from one side of the car to the other, dropping bits underneath, straining on difficult bolts etc..
Photograph everything before and during dismantling, this was absolutely essential when putting stuff back.
Have tons of rags for cleaning ( I got rid of all my old shirts)
Get a big plastic box and a 5 litre can of engine cleaner for cleaning parts.
Don't spend 8 hours cleaning valves (mine were caked in 2mm thick solid ceramic deposits) when you can buy them on ebay for a few quid.
Compression test figures mean nothing. Mine varied between 155 and 175, the highest being where the head gasket had more obviously failed.
Don't run an engine for years with a ticking exhaust, the leakage eats away the manifold faces.
Plastikote HIGH TEMP paint says what it does on the tin, my old repaired exhausts look mint sprayed up. One 400ml can per exhaust.
High temp epoxy is ideal for sticking the trumpets back in. If mine were loose, so must a lot of others.
Don't worry about high mileage, oil replacement is the key. My bores looked brand new with no wear ridge at 78k.
Don't use rusty bolts even if you've cleaned them (cleaning is a waste of time just buy new). My valley bolt snapped as I put it back and was a pig to get out so I replaced all bolts with new stainless as I went along.
Check the length of all new bolts, some of mine were too long (valley bolts & exhaust).
Shimming the rocker shafts takes a lot longer than you think! Mine were just out of tolerance, possibly because I had reground the valves, possibly it hadn't been done properly in the past, maybe just wear & tear?
Hold the head gaskets in place with pencils as they slip out of place while you fiddle with the head.
Get a telescopic magnet pen thingy from the pound shop, best quid I ever spent, even picked up dropped spanners.
In fact, get someone else to do the lot for you.
Regards
Mark
Put aside at least 7 full days
If you are going to do the job properly and renovate as you go along then I would recommend you remove the engine. I probably wasted 3 days just moving from one side of the car to the other, dropping bits underneath, straining on difficult bolts etc..
Photograph everything before and during dismantling, this was absolutely essential when putting stuff back.
Have tons of rags for cleaning ( I got rid of all my old shirts)
Get a big plastic box and a 5 litre can of engine cleaner for cleaning parts.
Don't spend 8 hours cleaning valves (mine were caked in 2mm thick solid ceramic deposits) when you can buy them on ebay for a few quid.
Compression test figures mean nothing. Mine varied between 155 and 175, the highest being where the head gasket had more obviously failed.
Don't run an engine for years with a ticking exhaust, the leakage eats away the manifold faces.
Plastikote HIGH TEMP paint says what it does on the tin, my old repaired exhausts look mint sprayed up. One 400ml can per exhaust.
High temp epoxy is ideal for sticking the trumpets back in. If mine were loose, so must a lot of others.
Don't worry about high mileage, oil replacement is the key. My bores looked brand new with no wear ridge at 78k.
Don't use rusty bolts even if you've cleaned them (cleaning is a waste of time just buy new). My valley bolt snapped as I put it back and was a pig to get out so I replaced all bolts with new stainless as I went along.
Check the length of all new bolts, some of mine were too long (valley bolts & exhaust).
Shimming the rocker shafts takes a lot longer than you think! Mine were just out of tolerance, possibly because I had reground the valves, possibly it hadn't been done properly in the past, maybe just wear & tear?
Hold the head gaskets in place with pencils as they slip out of place while you fiddle with the head.
Get a telescopic magnet pen thingy from the pound shop, best quid I ever spent, even picked up dropped spanners.
In fact, get someone else to do the lot for you.
Regards
Mark
Quick way to clean valves: put them in a drill chuck (ideally on a pedestal drill) then attack them with emery or those 3M style abrasive wheels. Obviously you don't emery the bearing surface of the stem but the rest is fine. Oh and wear a mask, the dust is horrific.
I've seen RV8s with over 100K miles and still no wear ridge on the bores. The greater risk is that years of unsympathetic morons thrashing them from cold has run the crank bearing shells down to the backings.
While your heads were off it might have been a good ideal to Helicoil all the exhaust manifold threads: come the day when you strip one you'll be taking the head back off as there's no room to do it with the engine in the car.
I've seen RV8s with over 100K miles and still no wear ridge on the bores. The greater risk is that years of unsympathetic morons thrashing them from cold has run the crank bearing shells down to the backings.
While your heads were off it might have been a good ideal to Helicoil all the exhaust manifold threads: come the day when you strip one you'll be taking the head back off as there's no room to do it with the engine in the car.
I used a B&Q medium grade, paint and varnish remover (abrasive wheel) attachment for a drill on mine.
The valves were caked in crap of granite like qualities and about two minutes on each with the 'tool' they were like new!
Using the same method to remove the flaking paint from the suspension at the moment
.
The valves were caked in crap of granite like qualities and about two minutes on each with the 'tool' they were like new!
Using the same method to remove the flaking paint from the suspension at the moment
.Well done Mark - the worst is over!
>> Get a telescopic magnet pen thingy from the pound shop, best quid I ever spent, even picked up dropped spanners.
Yeah I got myself a springy grabber thing. If I cant grab the culprit then I put a strong magnet in the grabber and fish about with that.
I wouln't remove the engine - some of those head bolts need a lot of torque, and the engine on its own would just spin about ;^)
>> Get a telescopic magnet pen thingy from the pound shop, best quid I ever spent, even picked up dropped spanners.
Yeah I got myself a springy grabber thing. If I cant grab the culprit then I put a strong magnet in the grabber and fish about with that.
I wouln't remove the engine - some of those head bolts need a lot of torque, and the engine on its own would just spin about ;^)
Hi Mark
Good to read about your diy gasket replacement and things went well, it all takes time.
Dont know if you remember me from the Cumbrian run down the runway i was the the one that fixed your throttle for your journey home, I should have asked Brian if you made it ok.
Hope to see you at Crooklends some time
Cheers
Campbell
Good to read about your diy gasket replacement and things went well, it all takes time.
Dont know if you remember me from the Cumbrian run down the runway i was the the one that fixed your throttle for your journey home, I should have asked Brian if you made it ok.
Hope to see you at Crooklends some time
Cheers
Campbell
Hi Campbell, good to hear from you. I could have done with you over the last couple of weeks!
Yes, your fix was superb, so good it was a pain getting it off to fit a new cable! I was gutted to see the times posted after the airstrip run as my car had beaten quite a few even though the cable snapped when hitting fourth gear causing me to coast the last third of the way. Those Chims must be dog slow!
Since we last met I've replaced the head gaskets, overhauled the heads and plenum, fitted an uprated radiator and modified the induction. Everything seems to be OK now, no water loss, low engine temp, no exhaust ticks, and smoother tickover. Car feels even faster than ever.
I can't believe the car has been off the road for 3 months, it feels like a lifetime.
Hopefully, I will get up to Crooklands next meeting.
Grateful regards
Mark
Yes, your fix was superb, so good it was a pain getting it off to fit a new cable! I was gutted to see the times posted after the airstrip run as my car had beaten quite a few even though the cable snapped when hitting fourth gear causing me to coast the last third of the way. Those Chims must be dog slow!
Since we last met I've replaced the head gaskets, overhauled the heads and plenum, fitted an uprated radiator and modified the induction. Everything seems to be OK now, no water loss, low engine temp, no exhaust ticks, and smoother tickover. Car feels even faster than ever.
I can't believe the car has been off the road for 3 months, it feels like a lifetime.
Hopefully, I will get up to Crooklands next meeting.
Grateful regards
Mark
Gassing Station | Wedges | Top of Page | What's New | My Stuff