The 8 inlet guides are pretty uniform as they vary between 19 and 20mm
The 8 exhaust have more variance at 13 to 15mm
I can measure they fairly easily because the valves are out as are the heads and all were measured at the place you will see mid guide as looked through their ports , you may or maynot be able to see the inlets have obvious bottoms in the casting , though both set of figs are pretty right for the areas .
Depending on your circus skills you should be able to cut a piece of plastic , piece of cardboard etc to small range of widths and poke them up against the guide protrusion and with your circus stuff and a light you should be able to see if there is a difference .
The over all of these guides is around 62mm but i can measure inside the guide to get a length , with the valve in it i don`t see how you can check this , putting a straight edge over the guides they are pretty much the same .
‘Valve guide installed height 'A' = 15.00 mm
(0.590 in).’
Philip have you seen the drawing with dimensions? My feeling is 15mm from the spring base.
PLR wrote :
‘edit .. when looking at you pics it struck me that there didn`t seem to be enough length of valve stem visable as compaired with what`s in the shed .’
peter – that is exactly what I am thinking. that valve is down about 3 mm and is sitting on the piston top. If I lift it up it still only has 295 thou travel till the collet hits the seal.
Am back home now so can’t do any more measuring.
think I will just ring the workshop who reco’d the heads tomorrow.
Thanks for all the input. Shall update with what the shop says.
Regarding the camshaft here are the specs of OEM for 3.9/4.0/4.6. there appears to be a big difference between the 4.6 and others. Does anyone know what is driving this, is it the bore stroke ratio or something else. If I go back to oem then at least I have a good baseline. But am struggling to find anything to justify or those whom have experience with 4.6 doing such (other than the dynotec cam TRS used to put in which people are generally disappointed in.)
The motor is 4.6 with thor manifold, o2 sensors, injected lpg, tin head gaskets so CR up around 10:1. am after best mpg so a torque cam.
Make Number Timing Period Valve lift Lifters Class Comments
Rover Standard 32/73/70/35 285° .390" Hyd. Production 3.9-litre (designation ETC 8686)
Rover Standard 28/77/66/39 285° .390" Hyd. Production 4.0-litre (designation ERR 3720)
Rover Standard 14/70/64/20 264° .416" Hyd. Production 4.6-litre (designation ERR 5250)
your aware i have a bias but the other 2 i was looking at were Tighe and Crow both of these have similar to your 4.6 numbers not the same though but it was a few years ago when i was looking .
The Tighe is 300AT
The Crow is 37613
Don`t know if either is suitable because i didn`t use either .
Spoke to the head recon place, they only had some old heads to measure off but had the same height to stem tip as PLR. Other than that really wanted to see the heads.
So bit the bullet and took one off today and voila….please see pics. all pistons on the side i took the head off have been hit by the inlet valves.
So what is normally the cause of this….the guys at the head shop are happy with the cam lift and obviously so are wade cams too.
This might be getting to my point of no return…..though I can have endless patience at times.
Interested to hear the cause other than the obvious ‘the valve done it’.
I’m still working out where to from here…I go into a workshop with a motor 45k old and come out with this stuff. FFS. (apologies).
Also spoke to wade cams about 4.6 cam – said it is most likely so diff from 3.9 because of emissions ie reduce overlap, bigger lsa etc they recommend not trying to replicate the 4.6 grind
IMHO there WAS nothing wrong with the heads and the guides are correct.
The cam lift, preload and/ or cam timing are obviously incorrect or the lifter sare too long.
You NOW may/will have bent valves so these will have to be checked and replaced if bent.
I would look at
1 the lift of the cam ( distance from centreline to tip of lobe vs stock)
2 the base circle diameter of the cam ( distance from centreline of cam to the back of the lobe) . this could be the cause of excessive preload.
3 the cam timing as installed ( seeing you have the other problems with the seals , it is probably more likely cam lift than timing)
4 That the lifters are the correct length
Seeing you have standard heads/gasket/ rockers/pushrods these dimensions should be OK.
I know that you say the cam maker reckons everything is AOK but They could have made a mistake. Not unheard of.
To check the lift etc, you could make up 2Vs to sit the cam in on its bearings and compare the heights with a dial gauge.
Regards Philip A
the more you get in the more you can see why it rattled .
I`d suggest all the pictures you have should be shown to the 3 places concerned , though i don`t think the cam mob have to answer for anything .
If the other two are reputable , i`d suggest they should replace , reimburse ETC .
I`d also suggest before you send the heads , you will need to remove some of the valves that have been obvious strikes and note if only the head of the valve is bent and not the actual stem above the head of the valve and look for any grab marks where the stem runs through the guide and if you find anything take some more pics . You can also then measure the length of the guide .
It appears the inlet valve in your pic is bent because it shows marking only part way around and as even bent they should still rotate .
Is it only the inlet valves that have hit , from what i can work out with your block pics they show 3 inlet hits , one piston is shown twice and one piston isn`t shown ?
I`d suggest the problem is likely to be cam timing , if the case it will require the removal of the timing cover and more pics and luckily i guess , you`ve already decided the cover has to come off .
These pics i`m suggesting are not for posting per se but as a record of what you find if you later need them .
I don`t know this for a fact but have seen it on the internet that by fitting 4.0ltr pistons to a 4.6ltr engine it will give a higher compression ratio , i also don`t know if this is right but i have on the internet on a UK specialists site seen quoted , the cc of the piston dome ( even though concave still refered to as ..."dome" ... neg - for concave and pos + for convex )... 4.0ltr at 13.23cc and 4.6ltr at 22.29cc both are neg so concave , being the UK they are talking the higher comp engine that is std there .
Our 4.0ltr up untill the last head gasket change used heads with a thickness on the tall side of 61.30mm the factory std thickness is as you know 62.56mm , the head gaskets used were 14 bolt composite of 1.03mm compressed .
So 62.33mm in total which is less than just the bare head thickness on a std factory head and as you know it uses a Wade 259A cam .
The valves have never touched the pistons and as you can see by where your inlet valves have hit the pistons the concave in the top of the piston doesn`t really come into it because they have hit on the piston top and not the dish . For comparision our 4.0 has a pistion to deck of 0.020" meaning when the piston is at the very top of its stroke it is another 20 thou to the block deck or top .
By the way i remember previously quoting the 14 bolt tin head gaskets at being thicker than actual , they are in fact thinner than a tin 3.5 gasket .
At the time i suggested using my memory that 0.75mm was the thickness , the thickness is 0.45mm .
I`m sorry for my error and the fact the nobody else bothered to set right my wrong memory .
On both sides every piston has been hit by the inlet valve.
When I pulled the timing cover off and took out cam last week I took some photos to help me put it all back together. So going by the photo today I recreated the same position of the timing marks and then turned it so the marks lined up ie join the dots.
Sure looks like it’s out a tooth.
As it may be difficult to determine if timing marks were lined up exactly as it was when I pulled it off I then took the chain off, set the timing marks correctly then put the chain back on. Then turned it to replicate the position it was in when I pulled it apart. I feel it shows conclusively the timing was out a tooth.
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