View Full Version : XE Valve clearance question
As a few of you know I'm building/having built a big power XE.
We've come to set inlet and exhaust valve clearances, using solid buckets, Newman PH5 cams, +1mm wasted stem valves and a 150' shim we have an inlet valve clearance of 80' which is a little large.
Does anyone know if we can run with a 230' valve shim? The largest QED stock is 180' we can manufacture some 230's if it'll work it just sounds quite big.
The valves measure 105mm as they should and the buckets measure the same as the ones QED have in stock. We just can't get our heads round it.
On the flip side the exhaust shims are down at 70' to get the correct clearance. Anyone any ideas?!?
BRoadGhost
29-11-15, 05:01 PM
The shims I just used were 11mm base to top with 6mm of solid; was pretty shocked to hear some builders just grind them by hand!
So to clarify if I can Mr Ghost sir,
http://i27.photobucket.com/albums/c175/grahampointing/top-hat-shim.jpg (http://s27.photobucket.com/user/grahampointing/media/top-hat-shim.jpg.html)
http://i27.photobucket.com/albums/c175/grahampointing/cam-follower-steel.jpg (http://s27.photobucket.com/user/grahampointing/media/cam-follower-steel.jpg.html)
Your top hat shims as pictured were 11mm total height and the recess that goes onto the bucket "finger" inside the bucket (for want of a better word) was 5mm and it added 6mm to the height of the "finger" in the bucket??
So we can make up some 230 thou shims with no real drama?!
We've got a proper valve grinder to machine them as we need.
BRoadGhost
29-11-15, 07:54 PM
I'm not overly enthusiastic about the collar shown in your top picture; why's it so shallow? That said once it's all together I doubt they'd fly out!
I measured mine in mm and gave 16 individual bags to my machinist stating the various total heights; greased them to hold in place during assembly & not had issue.
The ones in the pic sit with the recess on top of the valve hence why it's small any bigger recess and it would touch the collet not the top of the valve
I'll give Darren the go ahead to machine some up at 230 thou!! easy peasy!!!
BRoadGhost
29-11-15, 08:19 PM
I fitted mine into the convex bit of the lifter up the other way, went on nice & snug with grease.
Don't rush the build & certainly dont' rush running it in! Triple check every bolt!
Engine is being assembled by a very reputable engine company locally mate, I wouldn't risk building it myself, the level of detail they are going to is beyond my skill set!!
Darren said he wants to fit them recess into the bucket as you describe
BRoadGhost
29-11-15, 09:29 PM
A lifter will have less deviance on it's path compared with a sprung valve (top); some say to remove the spring location cups, but given how much these parts actually rotate at high rpm I'd prefer to keep them!
It's easy for someone else to tell you to go for it yourself, but everyone's different; all I can say is really take your time & if anything isn't perfect then go back & do it again purely for peace of mind.
I'm more than capable of doing it, despite my skillset comment, but my wife and I are trying to get approved as adopters at present and I'm so busy with work it's just a time factor really, plus tooling to do the job, the boys at Modus have everything!! Darren and Jay have also just built another 20XE for someone else with a Nova, along with many other big power engines, their reputation locally speaks for itself. Trust them 1000%
I agree with the idea that the lifter will have less deviation it in path compared to the valve, that makes total sense!! I also specifically asked QED about spring cups and they said it's a no also to remove them.
steveboyslim
30-11-15, 09:07 PM
?
BRoadGhost
30-11-15, 09:09 PM
That could be bad news if people have had some fail before
I'm more than capable of doing it, despite my skillset comment, but my wife and I are trying to get approved as adopters at present and I'm so busy with work it's just a time factor really, plus tooling to do the job, the boys at Modus have everything!! Darren and Jay have also just built another 20XE for someone else with a Nova, along with many other big power engines, their reputation locally speaks for itself. Trust them 1000%
I agree with the idea that the lifter will have less deviation it in path compared to the valve, that makes total sense!! I also specifically asked QED about spring cups and they said it's a no also to remove them.
off topic but,Good luck with the adoption mate!, me and are lass have our pannel date on the 9th of December, i know what you mean about hard work!! but it will be worth it in the end!! how far along are you??? are you in stage 2 yet??? kind reguards Pete:thumb:
off topic but,Good luck with the adoption mate!, me and are lass have our pannel date on the 9th of December, i know what you mean about hard work!! but it will be worth it in the end!! how far along are you??? are you in stage 2 yet??? kind reguards Pete:thumb:
PM sent mate!! haha brilliant!!
I get shims made/have in stock which have 8mm location, they locate on the dick on the bucket.
The original design only has 2.4mm location and locate on the valve above the collets, but if you hit the rev limiter or get a bit of valve float/bounce the shims flip off even if located on the bucket, my deep locating shims do not come off, they do need to be ground to size, some followers have a tapered dick and need some of the location reduced to ensure they seat properly.
Try to fine out the supply of cam buckets, they look a bit thin on the perimeter wall thickness, some collapse, some split.
Steve
Thanks for your input Steve, appreciate your time and knowledge, the buckets pictured are just some stock pics from QED, I believe that I've got Piper buckets but as these were sourced by Phil, I'm not really in a position, nor do I have the inclination, to contact him to ask!!
I'll send you a PM and you can let me know about ordering some from you, grinding them is not a problem, Modus have a valve grinder so it shouldn't be a problem to get the sizes exactly correct.
It makes perfect sense about them being located on the "dick" instead of the top of the valve, Darren had expressed a wish to mount the shims this way also but was concerned that it wouldn't be possible with the shims I'd got from QED. He'll be over the moon with these shims!!
steveboyslim
01-12-15, 09:21 AM
?
230 thou thick shim is more than I usually used, I would suggest a different cam with a larger base circle diameter, I would guess that that cam has been reground several times or it is a standard cam which a profile with a lot of lift has been ground on to it.
Small base circle diameters give the cam buckets a hard time due to the high acceleration rate caused by the angle between the base diameter and the start of the cam lobe, larger diameter less angle.
Steve
The cams are brand new from Newman, PH5's, as far as I know they have been ground from blanks.
I'm also using +1mm valves, not sure if this would affect the valve clearance due to the seats being in a different position to accommodate the larger valve head. I'm going to call Newman to ask if they've seen this before.
steveboyslim
01-12-15, 09:36 PM
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Thanks Steve,
It is correct, you can see the stickers on the end of the cam, brand new PH5's which Newman list as cut from a blank.
http://i27.photobucket.com/albums/c175/grahampointing/D256CD67-2405-42E1-A7B2-16F2DE10784B.jpg (http://s27.photobucket.com/user/grahampointing/media/D256CD67-2405-42E1-A7B2-16F2DE10784B.jpg.html)
I'll pass this extra info onto him and see what the measurements say, he may well have already done this I just haven't got the info yet as he was continuing to look at the head and see what else may be wrong, he is telling me this, he's said he feels something is a miss with the 230 thou for the inlets as he feels this isn't correct and has asked me to do some digging to see what I can find out.
If you did the port boring would that have also included fitting the the +1 valve seats or would these have been fitted by Phil?!?
The way I'm feeling this head is going in the bin and I'll just send another one direct to Neil Roper and start again.
steveboyslim
02-12-15, 08:07 AM
?
Ah ok, that clears up what may have gone wrong atleast!!
I'll get the guys to check the installed spring length today and as above see how it looks as discussed above, that will give us an indication as to where the problem may lie.
I'll talk to them and see how they feel, it may well make more sense to bring it to you than chase our tails trying to work out what's wrong.
BRoadGhost
02-12-15, 10:25 PM
Build the head up complete & torqued correctly minus the lifter shims, then measure the cam to lifter gap for each valve (as they WILL be different); that simple.
Build the head up complete & torqued correctly minus the lifter shims, then measure the cam to lifter gap for each valve (as they WILL be different); that simple.
We will be setting the final gaps by full assembly, we're only using the valve clamp to get the shims as close as possible.
We have a standard head with standard valves that we are going to try with the cams and buckets to see if we can get a decent inlet and exhaust valve clearance, this should tell us that the cams and buckets are correct, the cams are brand new after all and the buckets, cam face to "dick" measure exactly what QED have on the shelf so they appear correct aswell.
Our line of thinking currently is that the valve seats have not been cut correctly for the +1 inlet valves meaning the valve isn't sitting into the head as far as it should. Obviously we can't cut 80' (or 2mm in new money) out of the seat so we are thinking what options we have.
I guess at the end of the day the fact we're running a 230' shim doesn't actually matter providing we have all the correct spring bind clearances, valve to piston clearances and full valve lift from the cam profile.
As Darren has said something just didn't look right, QED assure me that they supply 230' shims on other engines the hold parts for so it's not as if no-ones ever heard of shims that big. Piper stock a 6mm shim to fit a 7mm valve stem so....... it's not unheard of.
steveboyslim
03-12-15, 08:25 AM
?
Steve,
We're still in the investigation stage. Comparing the head I have with the standard head we have in stock.
If it appears that we have standard valve seats then we're well aware that we can't cut +1's into them (as stated above) and would require new seats and by extension the throats would need to be machined also, possibly something that we would require someone with extensive experience to do (with reference to the throat work), valve seats we can change but removing material from the throats is sometimes best left to guys that have experience with the specific head. (Namely yourself)
I appreciate all your input, whilst it's sometimes easier to just send the head to you straight away, we don't learn by doing that, it's a voyage of discovery after all!!!
So, just got off the phone to Darren, my head does indeed have standard valve seats on the inlet. A standard valve works with my head and gives and expected valve clearance.
Now for the solution!!
steveboyslim
03-12-15, 05:14 PM
?
Thanks Steve,
The stems have been changed for what I assume to be colisbro ones, the guys will have checked them already and we know they are new just not the make.
Jay and Darren are proceeding with changing the valve seats for some +1mm items as it appears that the inlets a simply standard sized with a new seat cut but nowhere near right enough for the +1 valves.
The exhaust valves, which are +1 also, seem to have simply had new seats cut deep into the standard size seats. We can't believe this would be the ideal solution and would also explain why the shims for the exhaust were down at 70' cos they're cut too far into the seat.
The long and short is, new seats all round.
Another really interesting point that has come about today, the port bored Coscast head that we're using has got smaller throats directly above the valve than the standard GM head, this makes no sense to us?!? Indeed when Jay called QED to ask if they knew anything about the Coscast head having smaller throats they knew nothing at all about, very strange.
Steve, is part of the port boring process to narrow the throats? surely this would only be achieved by welding material into the throats and there's no evidence of this so we can't figure it out!! Have you ever come across a Coscast head that has narrower throats than the GM one?!?
The end result we've decided on is to fit the +1 size seats and open the throats and blend into the new seats. This is without doubt the best solution.
steveboyslim
03-12-15, 10:03 PM
?
Thanks again Steve, I'll pass that info on, the only issue we can see is that the exhaust needs a shim at 70' to get the correct clearance, which seems quite small, would you be ok with this!?
As for shims we'll get the seats fitted and see what the shims we have are saying, I've spent nearly £300 on shims at this point so I'd like to see if the ones we have will work first!!
The fucks alll the question marks all about
It's what all the cool kids do nowa days old man
The fucks alll the question marks all about
I don't know mate, Steve has changed all his posts to ? for some reason, no idea why.
TallDave
05-12-15, 01:43 AM
http://www.pngclub.com/forum/images/misc/quote_icon.png Originally Posted by Andy http://www.pngclub.com/forum/images/buttons/viewpost-right.png (http://www.pngclub.com/forum/showthread.php?p=2279848#post2279848)
The fucks alll the question marks all about
I don't know mate, Steve has changed all his posts to ? for some reason, no idea why.
Dunno this Steve Slim Boy character, come to think of it I don't know any of the characters on here, but that aside, isn't it all getting a bit cloak and dagger?
Maybe I'm missing something but surely a forum is about open discussion's and maybe even learning stuff....?
Mr Tall, I like to try and learn, otherwise what's the point in life!!
We had a situation that didn't make 100% sense, Darren asked me if anybody has come across it before, as although he and Jay @ Modus are exceptional engine builders they don't build high power XE's every week. Maybe running +1 valves on standard seats gives a power advantage?!? They weren't sure, so before setting about replacing valve seats and re-cutting it all they wanted to ask if this was something anyone's seen before.
Now we have our an answer and know what to do, thanks in no small part to Steve's help., So as to why all his helpful posts have changed to ? I have no clue other than the fact his last post asked if I was going to buy some shims from him as discussed earlier in the thread and I said I'd like to try and use the £300 worth of shims I've already got, then the next morning all his posts have changed to ?.
steveboyslim
05-12-15, 09:50 AM
Nothing to do with the shims.
I have replied to your PM.
Steve
Can this thread be deleted by a moderator please.
The information contained was of a sensitive nature and therefore should not have been shared openly. Now said information has been removed the thread has no point.
Why post it in the first place then?
What's happened to make somebody throw a wobbly?
I built an XE lawn mower and had a similar valve problem so this info would be useful to me
http://i27.photobucket.com/albums/c175/grahampointing/a8W58q3_700b.jpg (http://s27.photobucket.com/user/grahampointing/media/a8W58q3_700b.jpg.html)
Bizarre.As said threads are to help others with similar problems.
Southie
05-12-15, 01:28 PM
I've closed the thread but tbh the whole point of having a general car chat section is really to share amongst others for reference.
So if your not wanting to post in a thread then just pm someone.
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