|12-19-2012 03:10 PM|
I've got no idea what's going on with that one
The engine spec is the same for both graphs......with the only exception being the work done to the cylinder head
|12-19-2012 12:37 PM|
.. LOL! Nobody would ever accuse that engine of having a flat torque curve!
.. I am amazed that the earlier head catches up with the later head at 6200 RPMs... I would have expected the earlier head to just keep losing ground... wonder what's going on there? The less efficient earlier head must cause the engine to keep revving trying to reach its peak power for the cam used...
|12-19-2012 10:56 AM|
|ant_8u||Haahaa, not bad Vinnie|
|12-19-2012 10:49 AM|
post 25? lol.
remember the year of the technology.
still the car should be fun to drive
|12-19-2012 10:41 AM|
|ant_8u||Torque and power seem to drop off a cliff|
|12-19-2012 10:35 AM|
I'm starting to feel quite relaxed again, so thanks to everybody for that
I'll ask him about the valves next time I speak to him
So, we'll run it as is and see what the outcomes is
I've managed to find a graph of another Triumph owners engine which has been worked on by the chap that's done my head
The fine lines show his engine with someone else's head
The bold line shows the engine with the same head as mine (allegedly)
Everything else remained unchanged
Seems a big difference for just a head swap?
|12-19-2012 10:07 AM|
So you need to measure the installed height of each valve and shim the springs to give the correct installed height. While there are dial spring height tools, I use a snap gauge and caliper to measure this. The problem w/some dial tools is the top of the tool doesn't always match up to the retainer spring seat, so it has to be shimmed or otherwise somehow account for the mismatch.
No machinist worth his salt will have set you up w/a situation where the seats are too tall, that's to say to give a too-small installed height. But because the new exhaust seats look to be a bit recessed (not that much of an issue especially on the exhaust side), and that the intake seats were refinished (which sinks them slightly) this should not be an issue.
While I certainly understand your desire for perfection, in the greater scheme of things the difference in output between the two different intake valves would not amount to a measurable difference, all else being equal. Not saying don't change them- just saying.
|12-19-2012 09:13 AM|
The reason I used this guy was that he came very highly recommended
I told him what the car will be used for, but basically told him to build/prepare it to the very best of his ability
We agreed what would be done, but it seems that he hasn't done a lot of the requested work, stating that it was fine as it was
The head did come back assembled, but not cleaned
That along with the different valves is what got me to start this thread
I have no doubt his knowledge and ability is far greater than mine will ever be, but I think I have a different mindset to him
For example - The way I look at it, mismatched valves can't be right
And if its not right it has to be wrong, and I don't want things to be wrong
I know it's hardly critical, like we've mentioned, it's a weekend toy
But it'll bug me forever knowing the valves 'aren't right'
He also designs cams and headers for these engines, so my intention was to get everything from him so I know it's all correctly matched for the job
(Regarding valve heights.......since I have pushrods and adjustable rockers, do I still need to concern myself with valve heights?)
|12-19-2012 09:10 AM|
|killeratrod||Now that you have it bare take it to a good shop have it cleaned & magnafluxed. I would not go any further till you know the head is not cracked. These are the first steps you should take & the first $100 spent.|
|12-19-2012 08:50 AM|
I'm not familiar with the insides of a tr6 engine, but if i were you I would do as these fine gentlemen have suggested. if you are worried about the valves, try installing them in the appropriate locations according to the felt marker numbers. (your guy has marked them like this because he has matched each valve to each guide for fitment, also each valve to each seat for fitment and then finished by setting the installed height for each one). then lap each one quickly. then do an installed height check. if they are good, just go with it. don't think too much into it, you're not going racing right? just cruising the back roads on the weekend? i assume that if you were going to do some high rpm stuff then you would have taken your parts to somebody reputable for that application. the parts would have come back with all new stuff and look like they are new. those guys have to warranty their work, to a point, so they don't want to use any marginal stuff, and they want to fully assemble it so they know what the heights are, the spring tension specs etc. since yours didn't come back clean, or even assembled, we have to assume the machinist was giving you what you asked/paid for. sound correct?
if you are still worried,
if you lap the valves, check to see that there is a lapped ring all the way around the valve seating area and also on the head seating area. that way you know they are touching the seats all the way around. the ring should be roughly the same for all the intakes and also the exhausts. the intakes and exhausts will be different widths though.
take a look at the actual valves. check them against engine specs to see if they have enough margin.
then check for stem wear, galling marks or other defects. compare the stem measurement at an unworn spot compared to the worst worn spot. use a micrometer, not a vernier caliper.then compare that against engine specs sheet.
then check the area where the keepers ride to make sure that area is in good shape. you don't want to drop a valve because of a failure there. if there are burrs in that area then you may want to replace the valve and check the keepers closely, or just install new ones.
then check the keepers for wear.
then check the spring retainers for wear.
then check the valve springs for tension at installed height. or have it done. you can get away with shims to bring old springs back to within specs, but if parts are so cheap, why not replace them?
then check the valve guides for wear. make sure they are clean when you do this step. carbon in the guide will give you a false reading. that is why shops hot tank engines before they do any measurements.
then check the installed height against the spec sheet.hastings used to make a tool for this. it is like a piece of tubing threaded into another piece of tubing. it had a little set screw for locking it once set. it could be placed where the spring seat is and then a small straight edge could be used accorss the top of it against the end of the valve stem. you simply unscrew the tubing to expand or collapse the tubing untill it is the same height as the valve stem. then lock it and remove it and measure the length of the tube. that is the installed height of that valve. all the valves should be the same, intakes may be different than exhausts but all intakes should be the same as well as all exhausts. your guy probably already did this, or you could check with him at least.
then check the rockers and shafts or rockers and balls/pivots or whatever configuration you have there. check the rocker area where they contact the valve stem tips. make sure there isn't a divet there. check the pivot areas on the rockers for wear. check the end where the pushrod contacts for wear. check the pushrods for wear and straightness (roll them accross a clean sheet of glass or a "for sure" straight piece of steel). if the pushrods are hollow and are an oil gallery for the rockers, then make sure they are clean and clear inside. check the shafts, if applicable, for wear and proper oiling. if they are hollow make sure they are clean inside.
check the lifters for wear and/or pitting/cracking on the contact surfaces.
check the cam for wear and pitting/cracking on the contact surfaces
I could go on, but it should all be outlined in the engine manual. this is starting to look like a small novel, so I will stop now.
|12-19-2012 07:37 AM|
I think we'll just have to run this one and see what happens
I haven't got the block and pistons handy to take any pictures, but they're the same as the TR6 engine in the link you posted earlier
Restoration of a 1970 Triumph TR6 by Edwin Treffers/Rebuilding the engine/TR6 - engine ready for head
The pistons are flat, and level with the block
I've been told by various people to take 0.010" off the block deck
The head gasket is apparently 0.035" compressed
|12-19-2012 01:27 AM|
The stem side of the valve can effect flow. The new valves are heavier because they're more tuliped than the stock valves. While being heavier, they should flow a little better. Backcutting the valves w/a 30 degree cut next to the seat could show a modest improvement.
I have sure seen better looking hand porting as far as looks go, especially the exhaust side. That said, if the guy is supposed to know these heads, I'd give him the benefit of the doubt until I knew better. Truth is, looking at your ports and chambers doesn't tell me much because I'm not familiar w/the heads and what they're supposed to look like. So for that reason I'm withholding judgement. In the end it's what the engine performs like that will tell the story. Unfortunately there's no real way around this other than using a flow bench to compare before and after- but even then I have seen less-than-stellar flow numbers that run very good, and good numbers that don't perform as expected.
At this stage, swap out the valves if you feel there's something to be gained in performance/€.
If you could, post a photo of a piston. I'm wondering how much of a quench effect they'll give w/your chambers. Even when it looks like there's not that much flat area, tightening the piston to chamber clearance (within safe limits) can induce turbulence that'll help reduce the tendency to detonate. Your heads do look to have useable quench areas, though. This is if you have a selection of head gasket thickness to choose from. If not, you're basically left w/whatever the clearance is.
|12-18-2012 08:39 PM|
|ant_8u||Excellent, thank you|
|12-18-2012 08:28 PM|
|BuzzLOL||. Flat tops on the valves doesn't hurt anything... maybe clean off the dirty ones...|
|12-18-2012 07:58 PM|
He did the port work with a die grinder
Doesn't look like much was done to the exhaust, but maybe there wasn't much work needed
Is the level of finish up to standard?
It obviously doesn't look pretty in there - but I know that's not what it's about
Is it as good as it can be performance-wise?
I'll ask him about removing the edges round the valve seats
What do you think about the valves?
He said he doesn't rate the ones I already had in the head.....but he didn't change them like he was supposed to
As I don't want mismatched valves I intend to do something with them
Do my current valves look a nice shape, or are they too flat?
|This thread has more than 15 replies. Click here to review the whole thread.|