**** poor head JOB + questions
Discussion
Just to clarify, Cerdad, whom some of you may know - Is my dad and this is his car, I just do all of the work on the car for him!
After receiving the heads back from a well know "reputable" tvr company at the beginning of the year, It struck me quite quickly about how unprofessional it appeared. The package was a dodgy box with some tape round and on opening said package, I was a little dismayed at the lack of protection. After then unwrapping, if you could call it that, the heads it was then very apparent at just how unclean the whole operation was. The whole cost of the work was not pocket change, and for the hours they billed and parts they used, I would expect a pristine quality perfectly clean head. But no. Once I started to scrutinise, I was very surprised at the fact they did not skim the heads, despite the fact that they said clearly on the invoice "Head skim Qty 2" @ £40 ea. Naturally I was quite annoyed, as the father unit being the short sighted guy he now is, didn't notice. After challenging them, they said they would correct the mistake. So, a couple of months ago, we had the heads back, and I dutifully unwrapped one of them to find it somewhat cleaner, but not as I would expect. Packaging aside on this occasion as my dad met up with the guy and collected them. I inspected the first head, finding that they had indeed skimmed the head, although not much. I didn't unwrap the second head at the time as I didn't think it was necessary and being sealed up from this "reputable" company left it well enough alone.
2 Months later now I am totally ready for reassembly I unwrap the last head, to find that it has NOT been skimmed and is just as filthy as the last.
To add insult, the wrapped up head now has signs of rust on the valves and guides, that I can only presume is as a result of trapped moisture all of the engine parts are stored in the conservatory and its only the heads that have exhibited signs of corrosion. Also, on this now unwrapped head, there is evidence of swarf left inside the rocker covers, thin shards of cut aluminium and the such.
Before I lay in to this company i need to have some facts straight. I remember that the last time dad spoke to them, something was said about corrosion and being too thin. Didn't sit right with me at the time but I didn't argue as I'm not in the know.
Dad has resided to the fact that he doesn't truly care, and can't be bothered any more. I am otherwise livid at the amount of money he spent on this work and we could have gotten a much better job at a local firm for less money IMO. It was sent to this company on the basis that they knew what they were doing. It just makes me question the whole job, if the outward appearance is anything to go by, what about the important bits, valve clearances seat angles etc? I feel that regardless, I am going to have to strip them down, clean them and do some work myself.
Anyhow, what is the optimal/minimum thickness of the head, and measured from where?
what is the optimal width of the valve seat contact area for this engine?
Finally, what are the differences between the red rose heads and the standard 4.5 heads, I am aware of a higher compression, but is this the only difference? What other engine differences are there?
http://s1258.photobucket.com/user/jodywiles/librar...
Opinions please, most appreciated!
After receiving the heads back from a well know "reputable" tvr company at the beginning of the year, It struck me quite quickly about how unprofessional it appeared. The package was a dodgy box with some tape round and on opening said package, I was a little dismayed at the lack of protection. After then unwrapping, if you could call it that, the heads it was then very apparent at just how unclean the whole operation was. The whole cost of the work was not pocket change, and for the hours they billed and parts they used, I would expect a pristine quality perfectly clean head. But no. Once I started to scrutinise, I was very surprised at the fact they did not skim the heads, despite the fact that they said clearly on the invoice "Head skim Qty 2" @ £40 ea. Naturally I was quite annoyed, as the father unit being the short sighted guy he now is, didn't notice. After challenging them, they said they would correct the mistake. So, a couple of months ago, we had the heads back, and I dutifully unwrapped one of them to find it somewhat cleaner, but not as I would expect. Packaging aside on this occasion as my dad met up with the guy and collected them. I inspected the first head, finding that they had indeed skimmed the head, although not much. I didn't unwrap the second head at the time as I didn't think it was necessary and being sealed up from this "reputable" company left it well enough alone.
2 Months later now I am totally ready for reassembly I unwrap the last head, to find that it has NOT been skimmed and is just as filthy as the last.
To add insult, the wrapped up head now has signs of rust on the valves and guides, that I can only presume is as a result of trapped moisture all of the engine parts are stored in the conservatory and its only the heads that have exhibited signs of corrosion. Also, on this now unwrapped head, there is evidence of swarf left inside the rocker covers, thin shards of cut aluminium and the such.
Before I lay in to this company i need to have some facts straight. I remember that the last time dad spoke to them, something was said about corrosion and being too thin. Didn't sit right with me at the time but I didn't argue as I'm not in the know.
Dad has resided to the fact that he doesn't truly care, and can't be bothered any more. I am otherwise livid at the amount of money he spent on this work and we could have gotten a much better job at a local firm for less money IMO. It was sent to this company on the basis that they knew what they were doing. It just makes me question the whole job, if the outward appearance is anything to go by, what about the important bits, valve clearances seat angles etc? I feel that regardless, I am going to have to strip them down, clean them and do some work myself.
Anyhow, what is the optimal/minimum thickness of the head, and measured from where?
what is the optimal width of the valve seat contact area for this engine?
Finally, what are the differences between the red rose heads and the standard 4.5 heads, I am aware of a higher compression, but is this the only difference? What other engine differences are there?
http://s1258.photobucket.com/user/jodywiles/librar...
Opinions please, most appreciated!
Edited by tofts on Monday 27th April 15:06
As far as I can see the pitting isn't anywhere to worry about. As long as the heads are flat, then you should be grateful that the skim is fairly light. The last thing you want is an overly aggressive head skim. It makes reassembly much more difficult, and the increased compression will immediately cause pinking necessitating a trip to Joolz to adjust the map to compensate. Even otherwise simple jobs like removing and refitting the fuel rail (on a 4.5) becomes a nightmare on an engine with skimmed heads.
I paid significantly more than £40 per head to get mine done (not by a TVR specialist), I don't think that is overcharging - assuming the work is done of course!
I paid significantly more than £40 per head to get mine done (not by a TVR specialist), I don't think that is overcharging - assuming the work is done of course!
The pitting didn't bother me, I wanted skimmed heads.
Map adjust its not a problem as its having a new ECU.
Any fitement wise, I don't really care about, its nothing I can't handle.
But when the bill is £1040 just for labour, another £380 for parts you get an idea why I'm so pi$$ed off.
Oh, that also desn't include vat....
what would you expect for that money?
Also, I feel the valve seat width is far larger than would be optimum.
Map adjust its not a problem as its having a new ECU.
Any fitement wise, I don't really care about, its nothing I can't handle.
But when the bill is £1040 just for labour, another £380 for parts you get an idea why I'm so pi$$ed off.
Oh, that also desn't include vat....
what would you expect for that money?
Also, I feel the valve seat width is far larger than would be optimum.
Edited by tofts on Monday 27th April 15:05
I thought as much.
When we originally spoke to them it sounded like a dandy idea, but in hindsight I should have given it to my local engineering firm. At the end of the day its only a head! I mean, you still have to take the same care an attention putting in guides and seats as any other engine don't you. If they were tuning it, then maybe it would be a different story but frankly any engineer worth their salt would be able to do what we asked them to do with little to no effort.
Oh well, needless to say that if they don't clear up the mess they made I will name and shame.
I have already had a couple of messages from members asking me and even problems with different companies. So it shows that these so call reputable firms are not what they say they are.
Go with the man you know and not some company because it has an affiliation with your vehicle.
When we originally spoke to them it sounded like a dandy idea, but in hindsight I should have given it to my local engineering firm. At the end of the day its only a head! I mean, you still have to take the same care an attention putting in guides and seats as any other engine don't you. If they were tuning it, then maybe it would be a different story but frankly any engineer worth their salt would be able to do what we asked them to do with little to no effort.
Oh well, needless to say that if they don't clear up the mess they made I will name and shame.
I have already had a couple of messages from members asking me and even problems with different companies. So it shows that these so call reputable firms are not what they say they are.
Go with the man you know and not some company because it has an affiliation with your vehicle.
My opinion.
They have both been skimmed, although 1 more than the other. Did you spec a Chamber volume? As they certainly won't match now bank to bank, so you will likely have a differing CR.
They have taken the absolute minimum off (the rougher looking one) so as not to cause problems with knock (were they aware the car it was going in could handle higher compression?).
The pitting is due to corrosion from weak/incorrect coolant mix. Ideally this should have been welded up before skimming and they should have advised that.
Corrosion, not great and they should have used more oil to protect it but a conservatory is not a stable environment to store engine components.
I would also now be questioning how have the guides been installed, what the stem to guide clearance is etc. Also, if there is ANY loose material (swarf) then yes, I'd be stripping them myself and cleaning again.
Can you PM me who this "reputable" garage is.
As I'd like to avoid them in future.
They have both been skimmed, although 1 more than the other. Did you spec a Chamber volume? As they certainly won't match now bank to bank, so you will likely have a differing CR.
They have taken the absolute minimum off (the rougher looking one) so as not to cause problems with knock (were they aware the car it was going in could handle higher compression?).
The pitting is due to corrosion from weak/incorrect coolant mix. Ideally this should have been welded up before skimming and they should have advised that.
Corrosion, not great and they should have used more oil to protect it but a conservatory is not a stable environment to store engine components.
I would also now be questioning how have the guides been installed, what the stem to guide clearance is etc. Also, if there is ANY loose material (swarf) then yes, I'd be stripping them myself and cleaning again.
Can you PM me who this "reputable" garage is.
As I'd like to avoid them in future.Cy thoughts on the differing CR exactly, as far as I can tell, I think about 4 thou has been taken off of the head. The second head has DEFINITELY not been touched, this is evident as in the flesh it is very very clear, but beyond that there are sill small amounts of the original gasket left on the head.
I did't spec a chamber volume no, but I did say that we wanted the CR raised to that of the RR. Regardless, its not been done.
Pitting as you say is blatant, not terribly fussed as it doesn't effect the sealing surfaces of the gasket. It does sugest that the engine has some what overheated in the past coupled with a weak coolant mix has caused micro corrosion. Since owing the vehicle, a new radiator has been fitted as the old was rubbish and the ran temperature cut in has been reduced. Since this, (and at the time a good balance) it was running quite cool so issues on reassembly will have vanished.
No your right, a conservatory is not stable. But I didn't unwrap the second head and felt there should have been more oil for protection, as you say.
Your final point on guides is what now bothers me, for that reason. The whole build has come in to question and TBH i don't know if I would trust to send them back and have them finish the work. I also feel that the seat width is too wide, although I can't find anywhere the designated width for the cerb a general rule of thumb would be abotu 1/16 of an inch, which they are not.
All in all a poor job.
I did't spec a chamber volume no, but I did say that we wanted the CR raised to that of the RR. Regardless, its not been done.
Pitting as you say is blatant, not terribly fussed as it doesn't effect the sealing surfaces of the gasket. It does sugest that the engine has some what overheated in the past coupled with a weak coolant mix has caused micro corrosion. Since owing the vehicle, a new radiator has been fitted as the old was rubbish and the ran temperature cut in has been reduced. Since this, (and at the time a good balance) it was running quite cool so issues on reassembly will have vanished.
No your right, a conservatory is not stable. But I didn't unwrap the second head and felt there should have been more oil for protection, as you say.
Your final point on guides is what now bothers me, for that reason. The whole build has come in to question and TBH i don't know if I would trust to send them back and have them finish the work. I also feel that the seat width is too wide, although I can't find anywhere the designated width for the cerb a general rule of thumb would be abotu 1/16 of an inch, which they are not.
All in all a poor job.
Further to this subject, I have torn down the cleaner of the two heads, one because I wanted to do Port work, and two I wanted to check that they were ok.
Sadly, I still don't feel at all happy with the rebuild.
The seats were supposedly "cut". Ha, don't think so, most of the exhaust seats exhibit the typical darkness associated with heat.
Secondly, with the 2nd inlet valve in place, i think cyl no 5, and the valve approximately 10mm out from the seat, I can move the valve around 0.3mm in any direction....
Seems.... excessive, although I have yet to find any specs for the ajp. A general rule of thumb for any engine appears to be around 0.15mm intake and 0.2mm exhaust service limits.
So my 0.3mm intake is wildy off the mark.
I have a video demonstration of this http://youtu.be/D5tKcRwOJ_M - this was recorded yestrday afternoon. *EDIT - this is still uploading to YT and will be done at aroudn 13:30..
What do you think?
Oh and on a side note, they had put the wrong cam cap on the wrong journal. no 2 and 5 had been swapped over, very poor.
J
Sadly, I still don't feel at all happy with the rebuild.
The seats were supposedly "cut". Ha, don't think so, most of the exhaust seats exhibit the typical darkness associated with heat.
Secondly, with the 2nd inlet valve in place, i think cyl no 5, and the valve approximately 10mm out from the seat, I can move the valve around 0.3mm in any direction....
Seems.... excessive, although I have yet to find any specs for the ajp. A general rule of thumb for any engine appears to be around 0.15mm intake and 0.2mm exhaust service limits.
So my 0.3mm intake is wildy off the mark.
I have a video demonstration of this http://youtu.be/D5tKcRwOJ_M - this was recorded yestrday afternoon. *EDIT - this is still uploading to YT and will be done at aroudn 13:30..
What do you think?
Oh and on a side note, they had put the wrong cam cap on the wrong journal. no 2 and 5 had been swapped over, very poor.
J
Edited by tofts on Thursday 30th April 13:35
I wont name and shame just yet, as they deserve the opportunity to correct the mistake. But if they don't then I will make it open knowledge so as this does not happen in the future.
To me this is a £500 job you would expect on a normal engine. I know setting up the cams can be a ball ache, but really its not that hard at all. I will do this myself, just need to get a whole bunch of shims....
You are quite right with the valve pitting, especially the exhausts. They have not been cut in the slightest and look quite poor actually, I haven't had the chance to blue them up yet but I bet that some won't seal particularly well.
I don't suppose there is such thing a shim box on the forum, there used to be one on a previous car forum I was on? Think I will make a separate post for this at some point.
To me this is a £500 job you would expect on a normal engine. I know setting up the cams can be a ball ache, but really its not that hard at all. I will do this myself, just need to get a whole bunch of shims....
You are quite right with the valve pitting, especially the exhausts. They have not been cut in the slightest and look quite poor actually, I haven't had the chance to blue them up yet but I bet that some won't seal particularly well.
I don't suppose there is such thing a shim box on the forum, there used to be one on a previous car forum I was on? Think I will make a separate post for this at some point.
tofts said:
what is the optimal width of the valve seat contact area for this engine?
Finally, what are the differences between the red rose heads and the standard 4.5 heads, I am aware of a higher compression, but is this the only difference? What other engine differences are there?
Hi Jody,Finally, what are the differences between the red rose heads and the standard 4.5 heads, I am aware of a higher compression, but is this the only difference? What other engine differences are there?
I don't know the optimal width for the contact area but I asked to have three angle valve jobs when I had the machining work done but that engine builder who really does know his AJPs said he didn't recommend it for road going AJPs as it reduces that area too much, they need it to be quite big apparently. The red rose were meant to come with three angle valve jobs, but it seems not all did! A side from the other problems I've had I cannot fault any of the machining work I had done. All my seats had clearly been properly re-cut.
I didn't measure the movement after I'd had my new guides fitted but looking at your vid I'd say it was less than yours, though that is very subjective! Generally I think you can "feel" if there's too much movement, my old exhaust really felt bad before I had them done.
Well isn't that counter productive hey?
So it would be OK to promote good work, but not to contrary? What a silly ass ballsed up system, protecting the inept by allowing them to continue trading. then allowing other innocent people to make the same mistake. in a society that is meant to be fair just and free that is some what counter-productive.
Its Rules like that, that may have cost me all this money in the first place. I remember now why I don't like forums.
Credit where credit is due, but the opposite must also be allowed or the the credit has no meaning or basis for comparison.
So it would be OK to promote good work, but not to contrary? What a silly ass ballsed up system, protecting the inept by allowing them to continue trading. then allowing other innocent people to make the same mistake. in a society that is meant to be fair just and free that is some what counter-productive.
Its Rules like that, that may have cost me all this money in the first place. I remember now why I don't like forums.
Credit where credit is due, but the opposite must also be allowed or the the credit has no meaning or basis for comparison.
Big Al. said:
tofts said:
I wont name and shame just yet,
Word of warning, if you name and shame your thread will be removed. I had some shockingly poor work carried out on my Tamora last year. (one instance was a calliper repaint which cost £360, but they just quickly sprayed the calliper in situ and sprayed the discs as well)
I just posted the pictures with no comment, I just let the pics do the talking.
As others have said, mention your poor work on a TVR/Cerb Facebook group, where the post will not be removed.
I just posted the pictures with no comment, I just let the pics do the talking.
As others have said, mention your poor work on a TVR/Cerb Facebook group, where the post will not be removed.
tofts said:
Well isn't that counter productive hey?
So it would be OK to promote good work, but not to contrary? What a silly ass ballsed up system, protecting the inept by allowing them to continue trading. then allowing other innocent people to make the same mistake. in a society that is meant to be fair just and free that is some what counter-productive.
Its Rules like that, that may have cost me all this money in the first place. I remember now why I don't like forums.
Credit where credit is due, but the opposite must also be allowed or the the credit has no meaning or basis for comparison.
Like it or not those are the rules and always have been, even in Ted's days.So it would be OK to promote good work, but not to contrary? What a silly ass ballsed up system, protecting the inept by allowing them to continue trading. then allowing other innocent people to make the same mistake. in a society that is meant to be fair just and free that is some what counter-productive.
Its Rules like that, that may have cost me all this money in the first place. I remember now why I don't like forums.
Credit where credit is due, but the opposite must also be allowed or the the credit has no meaning or basis for comparison.
http://www.pistonheads.com/gassing/topic.asp?h=0&a...
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