Cylinder heads

jamesmartin said:

you could but it would be pointless unless you looked at every aspect of the engine ,you have to just look at what you want /expect ,its a subject than get a bit anal ,no point improving part of a system past the point another becomes hinderance

Click to expand...

yes exactly

i think we have to remember that it is a 2.5 tonne land rover, not a sports car!

what was really bothering me was that i thought i may have fitted SD1 heads that were worse than the land rover heads i took off.

now that i know they are the same i am happy to do the work and leave them, but still i wonder whether i should take the opportunity to make an upgrade...?

would be easier not to!!

How do,

The name's Jon by the way! I put an intro up but unless you're really bored it's not worth reading.

It's definetly worth throwing money at a good pair of heads, but if the engine is already generating enough grunt what you want to do with it you're just going to end up pressing the throttle a bit less?
That said, I do think ARP fixings are worth buying. You've only got to have the heads off a couple of times and they've paid for themselves for what you'd spend on a few sets of stretch bolts.

Cheers,

JC.

Mr Noisy said:

yes exactly

i think we have to remember that it is a 2.5 tonne land rover, not a sports car!

what was really bothering me was that i thought i may have fitted SD1 heads that were worse than the land rover heads i took off.

now that i know they are the same i am happy to do the work and leave them, but still i wonder whether i should take the opportunity to make an upgrade...?

would be easier not to!!

Click to expand...

id work with what youve got , then big improvements would be your mega kit

righto Jon/James,

i think for now we will call this a case closed, i will take the inlet manifold off and open up my ports to the gasket line and hope that does the trick, sure it will do because the gasket is well away:



i will pull the injectors first though and attempt to mark the hole so i can see where i do need clearance anyway.

then yes indeed it is time to start working on the megasquirt.

fair size task there indeed, im planning to remove the dashboard aswell so that i can have a bit of a general re-wire, got quite a lot of extra wiring that could do with being loomed now.

off to bed methinks,

hugely appreciate your collective help and knowledge!

onto the next problem!

cheers

if you turn the engine over so that the valve in the port you're fettling is closed, then get a bit of thin- ish choob (thinner than hosepipe) and tape it to then hoover, stuff it in the port to suck all the bits out.

that pic reminds me, my v8 leaks oil from that end seal near the dizzy.

Look what I miss in 24hrs!

Couple of points -

i) there is, in my view, no way that you will port match to the inlet manifold in situ - you won't be able to get close enough to the head to work accurately enough in the first place but more importantly you'll never stop the swarf getting in to everything and anything when you do it - as you'd expect it goes absolutely everywhere.

ii) I didn't know about the minor relief but from what I can gather on here it will only affect the spray pattern of the injector - there isn't any physical interference otherwise you wouldn't have got the injectors seated properly in the first place. If the engine is running OK I can't see that leaving it will cause any problems, particularly as you have moved to composite gasket which will have increased the height of the heads anyway.

iii) Given the budget and before you fit the mega squirt, why don't you spend the time re-working the heads that you took off and then just swap them over and fit your mega squirt? You can sort out the CR, get bigger valves put in at the same time with bulleted guides (the machining should be easily within your budget) and then spend the time porting and port matching inlet and exhaust. You can also, at the same time sort out the valve train geometry by dealing with the pedestals for the rocker shafts. You might go a little over budget with the adjustable push rods but you can buy those later! You will then have a set of heads that you can just swap over in a couple of hours and are worthy of the money you have spent on Mega squirt. (remember to machine the inlet port face as necessary at the same time as dealing with the bottom face to ensure that the inlet manifold still fits)

All JMHO of course.

Hi Jonny

Yes it has been a very quick thread this one!!

So here we are, new day, fresh head, clear view.

The plan is this:

Remove inlet plenum, pull injectors, look in holes.

Then decide what to do, whether it is worth opening the ports up for the sake of the little piece.

Please note I have TIN headgaskets and COMPOSITE valley gasket.

If I do decide to do the work, it will be an in situ port opening, simply using a pneumatic finger sander to remove material around the port opening, mainly at the top, to reach the gasket profile. I am quite happy there will be sufficient room to work. This will be done at TDC in firing order to ensure valve is closed, then good wash out with brake cleaner and compressed air etc.

I will consider opening the ports on the inlet mani slightly perhaps, but might not bother. I am also considering taking some length off the intake trumpets, perhaps 15mm. I think a little extra clearance will help with top end flow rate a fair deal, and it's an easy on-the-bench task.

The valve gear will not be touched, it is a standard cam in a land rover engine, and therefore it will have to do.

When I feel like having some fun I will tear down that engine I have waiting in the wings and have a play with a higher performance build, purely for pleasure and with no time constraints of getting it back in a vehicle.

Jonnyt thankyou again for contributing, I think we need to face facts that serious ****inh about is not worth it given the weight of this vehicle.

The Megasquirt will heavily improve drive ability and tune, but I think the mechanicals will be in sufficient shape to support the Megasquirt adequately.

I am quite keen to make sure the injector spray is happy though because my fuel will be quite precisely metered now, so need to make sure I get the best atomisation I can.

Anyway, first step, injectors out and see what's what!

Thanks again everyone, truly smashing help

I'm with you all the way except about trying to do anything to the ports while the heads are on the engine. Having done it on the bench the swarf really does get everywhere. Even the tiniest of pieces down the bore is going to cause problems, let alone the damage that could be done by any debris from the burr or sanding drum itself.

Ok Jonny, fair point indeed. I mean lets be honest, it's a half hodge at best doing it on the car.

I think with plenty of vacuuming it would be possible though? Who knows.

First job, lets have a look at the injector holes, can't decide too we can see for sure.

Something else I have looked at is a plenum base insulator.

It's like a big thick tufnell gasket that sits under the trumpet base and serves to thermally insulate it.

Couple this with a throttle body heat delete and I might achieve lower inlet temps.

Anyone had the experience?

I was thinking that say the trumpet base gasket is 15mm think, I then cut down the trumpets 15mm, so I keep the full length inlet tract, but I have extra 15mm clearance over the trumpet tops, nice.

Or do I just not waste time and money with something that barely achieves??

I may be wrong but i thought i read sum where that longer trumpets increase torque

Correct, the shorter the trumpet the higher up the rev range we get peak torque. Now being an off roader I want to keep my low end so I'm inclined to fit the spacer and then shorten the trumpets accordingly.

This will give the same length inlet tract, BUT provide 15mm extra clearance over the top of the trumpets, which is good for top end performance.

The question I ask is: is it worth £80 for this thermal insulator spacer, or do I just leave it all well alone as it was designed?!

waste tbh, doubt itl make much diff, water injection maybe??

I'm kinda thinking the same, doubt itll make much difference. I wouldn't mind if the inlet mani didn't carry coolant, cos then it wouldn't take much gasketing to make the whole lot cooler.

Will wait to see what the rest of the team think!

Megasquirt box arrives tomorrow!!!

Tomorrow night will get pics of them injector holes and pics of the mew stuff!

Well...



Quite a lot of obstruction in the injector hole, so I just got on with it, stripped it down, ragged it up and set about relieving the top of the ports.

Sorry Jonny, just had to get it done.

Done bank 1 tonight, will do bank two tomorrow.

Bad news is, like a fool, I cracked my plenum base trying to get it off

So now I need a plenum base, will upgrade to slightly flared and shorter trumpets if i can find an assembly at decent money, otherwise I need a standard one!!

Two steps forward...

Looks like the obstruction is far greater than the small amount of milling in the earlier pictures would suggest. How far are you going back into the head from the mating surface? Des Hammill's book suggests a minimum of 25mm to get the flows right.

Hi jonny

only worked back around 10mm into the head, effectively rounding over the top edge of the port.

not looking to open the ports for performance, just to achieve what land rover did and then a little more.

looking at the old engine, the ports are milled more so on one bank than the other, suppose it depends on the final position of the inlet manifold...?

have test fitted the inlet and we are now all clear, so im happy with that outcome.

tbh its too awkward to achieve much more than a small amount of opening with the heads fitted to the engine...!

will get a pic soon

cheers

Well done.

I'd suspect the difference in milling from one head to another is not intentional knowing Rover!

You see what I mean about it going absolutely everywhere?!

jonnyt said:

Well done.

I'd suspect the difference in milling from one head to another is not intentional knowing Rover!

You see what I mean about it going absolutely everywhere?!

Click to expand...

yeah i had a rag system going, with vacuum at the ready! managed to get full containment though, vacuuming the ports as i pulled the rags out!

Sorted

mud jointing compound