Amazing progress !
Well, I am not so convinced about RS schedules anymore...
Merlin Heads
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CastleMGBV8
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Mark,
Pleased to hear they have arrived at last, any chance you could post up some pics showing the port areas and the combustion chambers.
That's assuming you are not already busy with the spanners
Presumably you will still have to to do the oiling mod or have R/S put a restricted feed in for the rocker oiling?
Regards,
Kevin.
Pleased to hear they have arrived at last, any chance you could post up some pics showing the port areas and the combustion chambers.
That's assuming you are not already busy with the spanners
Presumably you will still have to to do the oiling mod or have R/S put a restricted feed in for the rocker oiling?
Regards,
Kevin.
Well looks like my valve cutouts are now in the wrong place. Wondering if I should start afresh with new pistons (4.0).
Also I will need to use exhaust manifold studs as the top row of holes goes through into the water gallery.
Will also need to skim heads to get them back down to around 27.5cc
Doesnt seem to be loads of room for roller rockers, need to check that too.
My ARP studs are way too short so need to sort them too.
They certainly look the business.
Think it will be a while before they are up and running as I have some track days booked.
Will try and post some pics tomorrow.
First impressions are very positive.
Mark
Also I will need to use exhaust manifold studs as the top row of holes goes through into the water gallery.
Will also need to skim heads to get them back down to around 27.5cc
Doesnt seem to be loads of room for roller rockers, need to check that too.
My ARP studs are way too short so need to sort them too.
They certainly look the business.
Think it will be a while before they are up and running as I have some track days booked.
Will try and post some pics tomorrow.
First impressions are very positive.
Mark
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CastleMGBV8
- Top Dog
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- Joined: Sat Aug 18, 2007 5:09 pm
- Location: Sidcup, Kent, UK
Mark,
Are the valves moved closer to the centre of the bore then? if so they should be clear of the outer raised edge of the piston where the cut outs are normally required so may not require additional piston work but check with RS.
I think RS do a specific stud kit for the Merlin heads,
What size chambers come as standard on the Merlin Heads?
Would have thought that RS would have ensured sufficient room in the rocker covers for roller rockers but again you will need to check with RS.
If you have standard 4.6 pistons swapping to 4.0 pistons will provide a useful increase to approx 10.88/1
Kevin.
Are the valves moved closer to the centre of the bore then? if so they should be clear of the outer raised edge of the piston where the cut outs are normally required so may not require additional piston work but check with RS.
I think RS do a specific stud kit for the Merlin heads,
What size chambers come as standard on the Merlin Heads?
Would have thought that RS would have ensured sufficient room in the rocker covers for roller rockers but again you will need to check with RS.
If you have standard 4.6 pistons swapping to 4.0 pistons will provide a useful increase to approx 10.88/1
Kevin.
Kevin yes valves are a lot closer to centreline.
<a href="http://s76.photobucket.com/albums/j30/V ... sition.jpg" target="_blank"><img src="http://i76.photobucket.com/albums/j30/V ... sition.jpg" border="0" alt="Valve position"></a>
Photo shows SD1 and merlin valves, must be approx 10mm difference between thir position.
The standard Merlin chambers are im told 31cc ( havent measured yet ).
I have been using 4.0L pistons but think I will get some new ones, where is the best place to get them?
Cheers
Mark
<a href="http://s76.photobucket.com/albums/j30/V ... sition.jpg" target="_blank"><img src="http://i76.photobucket.com/albums/j30/V ... sition.jpg" border="0" alt="Valve position"></a>
Photo shows SD1 and merlin valves, must be approx 10mm difference between thir position.
The standard Merlin chambers are im told 31cc ( havent measured yet ).
I have been using 4.0L pistons but think I will get some new ones, where is the best place to get them?
Cheers
Mark
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CastleMGBV8
- Top Dog
- Posts: 2334
- Joined: Sat Aug 18, 2007 5:09 pm
- Location: Sidcup, Kent, UK
Mark,
Interesting picture, can see the valve position in relation to the centre of the bore but not the edge.
To check clearance remove the valve springs on one chamber and with some engineers blue on the valve perimeters refit the head with the piston at TDC and rotate the valves, that should show exactly where the valves are in relation to the pistons. If that isn't clear enough a thin layer of plasticine on top of the piston will show the valve pattern more clearly.
Check you have sufficient clearance for the lift of your cam + a tolerance of 1-2mm. for a bit of extra comfort.
You probably will not need to replace your pistons, unless you have other reasons for doing so.
Kevin.
Interesting picture, can see the valve position in relation to the centre of the bore but not the edge.
To check clearance remove the valve springs on one chamber and with some engineers blue on the valve perimeters refit the head with the piston at TDC and rotate the valves, that should show exactly where the valves are in relation to the pistons. If that isn't clear enough a thin layer of plasticine on top of the piston will show the valve pattern more clearly.
Check you have sufficient clearance for the lift of your cam + a tolerance of 1-2mm. for a bit of extra comfort.
You probably will not need to replace your pistons, unless you have other reasons for doing so.
Kevin.
Sorry its not very clear.
Pic is of an Old 4.6 short block. I put one piston near TDC and pushed in some plasticine, then removed a couple of valve springs from each head Then starting with the SD1 head I placed it on the block and tapped the valves with a rubber mallet to get an impression. Then put on the merlin heads and did same. Just to get an idea of where the new valves are in relation to my old cutouts. Think I might get away without additional cutouts but when the time comes i will have to do a proper clearance check.
At the moment Im waiting for information from Real Steel as follows:-
No bolts or studs came with heads and as they need to be longer than standard I need to know what to use. Also I need advice about sparkplugs as they use the smaller type. Will my M238 cam be OK with the current springs? Can they supply stainless exhaust studs so solve the problem of top bolts going into waterways. ( dont want coolant loss everytime I take exhaust manifolds off.
Also need to work out how much to have skimmed off to get back to 27.5cc chambers.
Minorv8
I ended up phoning them on a weekly basis dont give up.
Mark
Pic is of an Old 4.6 short block. I put one piston near TDC and pushed in some plasticine, then removed a couple of valve springs from each head Then starting with the SD1 head I placed it on the block and tapped the valves with a rubber mallet to get an impression. Then put on the merlin heads and did same. Just to get an idea of where the new valves are in relation to my old cutouts. Think I might get away without additional cutouts but when the time comes i will have to do a proper clearance check.
At the moment Im waiting for information from Real Steel as follows:-
No bolts or studs came with heads and as they need to be longer than standard I need to know what to use. Also I need advice about sparkplugs as they use the smaller type. Will my M238 cam be OK with the current springs? Can they supply stainless exhaust studs so solve the problem of top bolts going into waterways. ( dont want coolant loss everytime I take exhaust manifolds off.
Also need to work out how much to have skimmed off to get back to 27.5cc chambers.
Minorv8
I ended up phoning them on a weekly basis dont give up.
Mark
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CastleMGBV8
- Top Dog
- Posts: 2334
- Joined: Sat Aug 18, 2007 5:09 pm
- Location: Sidcup, Kent, UK
