240 head removal

Rob Gaskin

Treasurer
Staff member
Site Administrator
So reading between the lines in Albrechts subtle post the top end has to come to bits then:eek:

Craig to inspect the valves, seats and guides (important) you need to remove the valves. I think the cam can stay in position.

Keep everything in order so you know which valve, rocker, lash-pad etc came from where.

You said you had a Haynes manual - have a look ;)
 

SKiddell

Well-Known Forum User
So reading between the lines in Albrechts subtle post the top end has to come to bits then:eek:

Without doubt a full top end or engine rebuild must incorporate a complete nut and bolt strip down and inspect.

Dissasembly of the head is not difficult and needs to be done if the engine has stood and oil has dried out to a resin consistancy

Keep everything in order (use a layout sheet on an imaculately clean bench, and lay components in order ie cylinder 1/inlet valve/rocker/lash pad/spring/collets/cap.....then cylinder1/exhaust//rocker/lash pad/spring/collets/cap)
Fingers off, collets out, springs out, valves out (look for valve guide wear) cam out (inspect lobes)....if its moves, unbolt, inspect and clean it.
 

Throttleton

Well-Known Forum User
Rob/Steve you are both sort of right about what I want. I would love to build a full on heavily modified motor, it's not made out of plastic but nonetheless I am enjoying the mechanical side. With the added bonus if ,I did it right, it would go like a rocket.
However if it 'went like a rocket' it would defeat my objective here which is to build the car stock so I can make a comparison with a steel 240. I want to take it to the drag strip and get timed and take it to a track for a few blasts. I also need, when it's done, is for someone with a stock 240 to have a go in it and vice versa if anyone fancies it:D
The point is not about being smug if it handles/drives better, but that would be nice, but to compare and improve the tub or subframe to make the car 'feel' how it should do, or as I want it to feel.
I know my car will certainly not be most peoples choice for sure but this will not be a 'kit car'. I am not glueing Lancia body body panels to a VW beetle floorpan. There is no donor car (important that bit). I am replacing rotten steel with composite to restore/repair the car. The man hours to get to this point are insane so I have to do it to prove to myself it can be done and properly.
I am pleased the thread has generated interest as I will need the advice of those in the know continually throughout the mechanical side of the build.
Luckily I have Stephen on board, whilst he is not familiar with the L series motor he is a 'no shortcut' sort off bloke when it comes to engine building and will keep me straight.
 

Albrecht

Well-Known Forum User
All joking aside, if you don't take the engine completely apart and at the very least hone the bores and re-seat the valves, then you are unlikely even to reach the stock level of power for the engine. That would skew your data for comparison, which is going to be subjective enough without any extra variables.....

From what you've already described, the engine is in need of thorough cleaning. You have to clean out ALL of the oil galleries and waterways ( bet you find a load of casting sand sitting in the bottom half of the block ) otherwise it will come back to haunt you at a later date. Don't spoil the ship for a ha'penny worth of tar.....

A complete stripdown means just that. Don't let it intimidate you. Once you come out the other side of it you will understand your engine a lot better, you'll know what you are dealing with, and it will always be a sound base to build on if you want to do something else with it later.
 

Albrecht

Well-Known Forum User
There is no donor car (important that bit). I am replacing rotten steel with composite to restore/repair the car.

This thread is not the place, and this is probably not the time, to get into a debate about the above. However, there's a pretty good debate to be had on the whys and wherefores of dumping "Part Number One" ( the thing that carries the car's official identity ) and replacing it with something else entirely.

Maybe not here and now though, eh?
 

MaximG

Well-Known Forum User
Removing the cam is probably one of the simplest jobs when stripping down the head. Care needs to be taken as the cam is steel and the cam towers are aluminium making it easy to damage the baring faces.
 

Throttleton

Well-Known Forum User
Thanks MaximG, point taken.
Albrecht you have hit the nail on the head. If I don't restore the motor to how 'it was' then the comparisons will allready be problematic so all advice will be listened to.
You mentioned the comparison is 'subjective enough' Anything you may think of to make it less subjective please mention. As I have said the plan is to to have the shell and subframe replaced whilst keeping as much as possible stock. I know there will be small things but hopefully they wont interfere with the general opinion at the end.
Albrecht, as I was writing the bit about the donor car I new it would possibly open a can of worms but felt it important to mention as I wanted people to understand my goal and reasoning behind the project.
I don't want any posts on that subject on this thread if no one minds. Like you said I'll save that for another day/thread. In fact that can be mentioned in the car build thread rather than the engine build thread. I don't mind that one getting spicy but I really want to see this thread to the end because if everyone keeps chipping in it will be a good read hopefully and of some use to other engine novices.
Cheers
Craig
 

Throttleton

Well-Known Forum User
Soaked all the manifolds studs with plus gas. They all came out easier than I thought the would. Plus gas is very good. Next week I will take all the parts off the head and keep in order. Is there is anything in particular took look out for regarding worn parts??
I'll clean the head and take to Duncans next week and hopefully get the thumbs up.
Pic attached Rob of the big water way, looks ok ??
The other pic is of a small waterway which the gasket seemed to have blocked off, is that normal??
How do you get a pic into the thread instead of an attachment??
 

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STEVE BURNS

Club Member
Two ways you can open a photo bucket account load your pics on there and then use the image button ( the one that has two mountains in it 3rd from the right from the you tube button) and load the picture there

Or open the attachment by clicking on it, right click on the picture and click on the view image info button copy the location hhtp.www. etc etc then click on the image button and paste in location a you have done it

It would be better to use the photo bucket method as if you load 100s of pics it can cause a problem untill we can sort out how to increase image allocation totals
hope that makes sense
give it a go and let me know how you get on if you fail bell me and will talk you through
 

Throttleton

Well-Known Forum User
head1-002.jpg


Brought the head home to do on the dining room table, missus not happy.

head1-003.jpg


Haynes manual showed a screwdriver compressing the springs enough to get the rocker arms out. I tried this and the screwdriver slipped as one of the rockers came out and the rocker guide hit me in the face:eek:. So used a big wooden spoon handle instead with no more injuries.

head1-004.jpg


The cam came out pretty easily. It got tight at a few points but I found if you rotate the cam each time a bit it takes the pressure off the compressed spring and it slides out ok.

head1-005.jpg


All bits kept in order and bagged up and labelled.

head1-006.jpg


Taking the springs out was a bit of a chew on without the right equipment but I was to keen to wait.
Definately reccomend buying a spring compressor!

head1-007.jpg


All the valves almost fell out so I assume I haven't bent any.
Do I need new valves or do you grinding paste them back in??

head1-008.jpg


Hacked the remnants of the scabby old gasket off which took an age.Sanded with a block until I could see some clean metal and cleand with a degreaser to see whats what.

head1-010.jpg


Seems to look ok , but what do I know. Going to Z Farm tommorrow for an honest opinion.
On the manifold side of the head in the middle at the bottom of the picture there appears to be 3 holes, the left one has been filled in with something. Same with the second top hole between pot 1 and pot 2?? Is this normal??
Anyways slow progress but I don't think I've a rsed anything up yet.
 

Throttleton

Well-Known Forum User
Off to the Z farm next week to get the head rebuilt and the pistons reconned.
Zedheads radiator issues have made me think about the standard rad.
Again my car will not be a competion car but I want to build and test it on the track.
Will I have any cooling issues on a stock motor, assuming I build it correctly, when I thrash it round a track for a few laps?? Obviously I don't want to wreck the build due to something simple but I also want to keep it all stock??
 

Rob Gaskin

Treasurer
Staff member
Site Administrator
Yes it's nomal for those 'holes' to be filled in.

A standard rad will be ok as long as it's in good condition. I ran with a standard rad for a while.
 

Huw

Club Member
Hi Craig

How is the rebuild coming along? I'm about to start the same journey as you, so it would great to hear how you are getting on with your motor.

Cheers

Huw
 

Throttleton

Well-Known Forum User
Hi Huw, I'm in the middle off taking the head off my hilux and it makes the datsun motor look a doddle.
Mine is stripped now ready to take to an engineering shop.
After advice on here and from Duncan I am getting the shop to do the bearings and also to lap the valves in. I got one off those rubber suction sticks to try but they are shyte.
I am also going to get the block honed as the bores are all varnishy.
If you keep everything in order for re-assembly and a haynes or similar it will be reasonably straight forward.
I have also splashed out on a posh torque wrench as I would imagine I would be a bit over the top with bolt tightening tbh.
If you do most off the work yourself I reckon the bill will be hundreds rather than thousands for sure.
I'll keep you posted.....
 

MaximG

Well-Known Forum User
Your going to pay to have someone lap your valves in, more money than sence. I did all 12 valves last week it it took less than an hour.
 

Throttleton

Well-Known Forum User
How did you do it mate? I have googled it and apparently you need to achieve a 1mm 'band' around the valve to achieve the right mating faces. The yanks put the valve stems on a drill to do it but I'm not confident. It is quite a bit of work to strip and build a motor but a lot you can do yourself, but I thought a few things might be better done by a shop. I would be upset if I rebuilt the engine and it was all good but the valves leaked a bit?
 

SKiddell

Well-Known Forum User
Craig
Do you know a good engine builder (yes) then why haven’t you rung or pm'd him for advice, when you do, you can tell him how his doors and dashboards are doing.

Seeing as this is a forum and as such a source of info, here we go, (for a mild tune road engine)
The old sucker and stick method is at best poor, barely adequate for even a trip down Tesco’s

Putting them in a "drill" is flawed as you can increase eccentricity, wear the valve guide and get a concentric ringed surface both on the valve and the seat, the "better" DIY tool as an oscillating drill attachment as it will "bed" the valve onto the seat

LASER%20TOOLS-FS-G4095.png



(can be had for around £30 or so at Machine Mart) and they do a reasonable job for a road engine, if care is taken

Start with a course grit and work to a fine grit
Use engineers blue to indicate contact area to get that consistant contact patch around the valve to seat interface.

For a more serious engine, (mild road tune to screeming track weapon)
Proper valve jobs are done on a specific CNC setup to a tolerance of 2 or 3 microns
 
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