Hi all,
I hope you all have a good christmas and an even better new years.
I have been waiting for my engine heads to be ready to go back on
the motor. After one of my number 1 valve guides broke a piece out the side.
The small piece went up into the plenem and down in to number 4.
So I have just got them back today and it has what looks like pinholes
on the face of the head, is this ok?
Cheers Shane
I also posted it on the bb forum .
http://www.alfabb.com/bb/forums/milano-75-1985-1993/277930-v6-head-work.html#post5084002
If the pin hole is clear of the head gaskets firing ring, which it looks like it will be, than that's fine.
Agreed.
thank's guys
So im going ahead with put them back together .
wish me luck these are my first v6 heads im putting back together,I'm thinking of replacing the spring on the rocker
shaft with sold bushings eg cut alloy tube to fit .
what do you guys think ?
cheers all
hi guys,
I finaly got around to fitting my head to the motor, Went back together without a hitch or
so I thought.
I have done something wrong not sure what.
I put on the timing belt and all the right lines line up. Both cams, dizzy, tdc etc.
So I have no compression in 6 and 5 cyclinder, about 60psi in 1, 4 & 120 psi 2, 3??? and I have noticed that the timing belt goes tight when turned over then loose the next, then tight again.
Note that I have not fitted the spark plugs yet.
Make sure that you have the head gaskets in the right way, not upside down or 180 degrees out, the bolts will still go in, but the cylinder heads won't seal.
The timing belts go loose and tight as the valves open and close, sometimes all the valves will be open and the belts are under tension and tight, when the valves are closed, the belts will be under no tension and loose.
On a Alfa Boxer, you have to set the timing belt tension with all the valves closed, so that when you set the tension the cam is free to rotate, not sure on a V-6.
Also make sure that the banks are on the right stroke, ie on compression stroke, you can have the cams out 180 degrees and the motor won't have valves and pistons coliding, but it won't be building up compression, i don't quite know how to check this offhand, look on the internet somewhere and someone will explain it better than i can, Colin.
thank's colcol,
I spend 20mins put the head gaskets i will really kick my self if i put them on backwards.
thank for the heads up on the timing belt, i thought i may have had a bent cam.
I tight the head down to 98nm like the book said, Is that tight a enough ?
There is no water in the block only oil about 5lt.
Tighten the fasteners to what the book says, if it says 98 newton metres, then thats the final torque, make sure the bolts are done up in seqeunce, ie don't tighten the first one to 98 n.m. then the second one to 98 n.m., there is a tightening order and start off and say do them all to 30 n.m. then 60 n.m. and finally tighten them all to 98 n.m., make sure that if the fasteners are meant to be oiled or not oil, it will make a difference to the final torque, Colin.
Hi All,
So i have retighten the heads to 100nm each and while I was doing that I noticed that the motor had no gap on the left cam (inlet side) I tried to put a filer gauge but connot even get the thinest one between them.
Are all the shims height in the V6's?
Cheers
The shims may need to be different heights. Only two of mine were the same, the other four different.
:)
Hi Richard,
What size filer gauge did you use to set your inlet valves too ?
So i have 2 cylinder at 120 psi 2 @ 60 psi & 2 @ zip psi .
Quote from: alphie75 on April 25, 2014, 08:01:02 PM
What size filer gauge did you use to set your inlet valves too ?
I just followed the workshop manual: 0.475-0.500mm (0.018-0.0197").
I have a photo where I labelled the clearance on one valve as 0.018".
:)
It sounds like something is wrong mate. Take it to your mechanic if you don't know what you are doing.
It's a bit hard to diagnose when nobody here can actually see what you have done.
gday
a small update. IT LIVES!!!!:P
I thought about the ideas that have been given to me off the forum and end using a fine stone to sand down the shims from 1.6 to 1.3 on number 6 cyc and got 50psi and all the others were about 65, 110, 120 etc
So I fired it up first pop and killed it(stop it with the key).
Started it once more for 1 min and killed again. All the cyc are now at the 100 mark so this weekend I
will be filling it with coolant.
Wish me luck
p.s. it's only been two bloody years since it broke.
Take the shims to an Engineering place with a SURFACE GRINDER and get them to grind them down properly, sanding them on a stone or sandpaper won't work, whatever finish you get with sandpaper you will put back on the component that the shim runs on and it won't be parallal, or go to an Alfa Wrecker or Specialist and buy the right shims, Colin.
hey col,
I have been bitten one too many time by so called " Specialist" that is why i am having a go
Now that you know what size you want, buy some new ones or have the old dunger shims that are worn or have pickup on them ground down accurately on a SURFACE GRINDER, but only a few thou, as you don't want to grind through the hardened coating, i have done this for my old Volksy and Alfa 33 and Alfasud and it works fine, don't waste your time sanding them down, it won't work properly, the shims have to be dead flat so depending if the camshaft has positive or negative this will rotate the shim so that wear will be averaged around on the shim and not just on the one spot, Colin.
hi
thanks for the advice, I think I will do exacly what you have suggested.
any one know of a person in Adelaide that can do the grinding?
Just tying to get my leads back from top gun atm, so I can get it running. They made them wrong the first time. I sent the my old leads and they still got them wrong. So its a waiting game atm.
Thanks for the advice
Cheers.
Try an Engineering Shop or and Toolmaking Place in Adelaide that has a surface grinder, but hurry up before they close down along with the demise of our car industry, Colin.
TOO TRUE It all a bit grim .
The only way to get by is working for a big cars parts shop.
hi all,
I've finally got the car going, but it sounds like a hairy goat.
I tried to set the timing, but it sounds like its hunting.
The timing mark is at the pin then it's gone and then its back then gone again and so on???
I'm thinking that I will have to reset the timing again.
Any Thoughts? TA
hi all ,
I'm feeling a bit annoyed .
So the reason that I am having no joy with my heads is because when they reconditioned the head they lapped the valves in so far that the shims were out a lot. Hence rough running.
So now.... to get head off and get the reconditioning guys to make the shims fit.
Not happy... its another $400.00 to spend.
If your planning to recon your cylinder heads.. best check your valve shims.
oh and it continues... bugger.
Only backyarders lap valves in with valve grinding paste, the cylinder head seats should be cut with a single angle tool, the valve should be dropped in and a vacumn test done to check for sealing, the valve should be ground on a valve grinder.
Then the valves should be assembled with the cams installed and the valve bucket to camshaft clearance measured, then to achieve the correct clearances, the cams are removed and the shims changed or surface ground or in some cases a few thou nibbled off the end of the valve stems.
Do a compression test to see if you have compression in all the cylinders, the valves may not be closing or seating correctly, Colin.
Check that the shim walls aren't bottoming out on the collets!
Thank you both, very valid point.
I would have thought this would have been pointed out by "Chris Milton engineering" the business who did the job originally.
I would have thought for *&^% $850 he might of let me know :o
Plan B
Looking into a 3L replacement. Might be the best option.
Cheers guys
Thanks
Here's a few photos of the problem child.
number two
number 3
4 and last one
You could correct the valve clearances by changing the shims, getting them correct, assembling it all and doing a compression test and if it comes up good, you might get a smooth idle with the valves closing properly and getting full compression to the motor.
I had a head reconditioned on an old Volksy a few years ago, the firm that did it told me that the shims were not correct, as they didn't have any shims or the special tools to change them, which i did, so i changed the shims, as i had a collection and the special tools to change them and a thousand kays later when the valves settled in, i had to change the shims again, if you have an older engine, always ask if the shims are correct, as that will be an extra charge.
All the modern engines for the last 30 years have hydraulic lifters, which set the clearances with oil pressure, so its install it, and off you go, Colin.
$850 is a good price for head work.
Did you specifically ask them to reset the clearances for you?
If you didn't, I'd say they aren't at fault here.
Just for reference, 850 is pretty close to what I paid a reputable shop for standard work done to one head, not two. It then took me near enough to 10 hours labour to reset clearances correctly. (I didnt have spare shims, I had to machine my existing ones). It can be a really fiddly and time consuming job, I dont think you can expect that sort of labour to be included for $850.
Having said that, if the rest of the motor is still good, I think you'd be making yourself a whole lot more work trying to do an engine swap if clearances are the only issue. It can seem like a never ending uphill battle, but youve come this far, why let it beat you now!?
AikenDrum105: My wife is the boss, I have no illusions about that mate.
Choderboy; I have compression on all cylinders but it very low, some are 500 kpa some and are 800 kpa.
Mat Francis: yes the price was ok. The point I was making was that nothing was said about the shim's
at the time. Now I have to pull it apart and again. Live and learn I guess.
And the gaskits that I got from the UK that I put on are now shot.... oh well.
Put some new gaskets in, then put the cylinder heads back on and do the clearances on the valves, do a compression test and see what it is like, don't know much about the shims on the motor, but on the Suds and 33's, you can change them without removing the camshafts.
If you cannot obtain shims, have them ground down on a surface grinder, but don't take more than about 0,1mm per side as you will break through the hardened case, Colin.
.
Quote from: colcol on August 13, 2014, 05:46:22 PM
Put some new gaskets in, then put the cylinder heads back on and do the clearances on the valves, do a compression test and see what it is like, don't know much about the shims on the motor, but on the Suds and 33's, you can change them without removing the camshafts.
If you cannot obtain shims, have them ground down on a surface grinder, but don't take more than about 0,1mm per side as you will break through the hardened case, Colin.
.
Colin, seriously mate, if you don't know, why say anything? It doesn't help his situation
We aren't talking about a 33 here.
Cam shafts need to be removed to swap shims.
Why take the heads off? Wind the crank a quarter of a turn so the pistons are all out of reach of the valves.
Cheers.
Alfie75 has stated that the gaskets that he got from the UK are now shot, if the head gaskets are stuffed then they will leak and you won't be able to form enough compression, so you have to bite the bullet and put some new ones on, unless you are talking about cam cover gaskets?, which won't cause a rough idle, but allow the oil to leak out.
But you need to set the valve clearances as the valves may not be closing and you will not be getting enough compression, Colin.
Forget the head gaskets, I wasn't talking about the head gaskets.
I was talking about setting clearances.
He has said the gaskets are "shot". I took that as he thinks they are wasted because he has to remove them. How can anyone know they are fucked if they are still on the motor with heads torqued down?
It doesn't matter, it's all speculation! We would need Alphie75 to clarify exactly what he means.
I'm saying, if clearances are out, and valves aren't closing, of course theres no compression. It's probably not the head gaskets, and since it can be shimmed with the heads on the car as I mentioned earlier, no need to pull the heads off. It seems ridiculous to me to remove the heads and take them back to pay a machine shop hours and hours of labour to set clearances.
I'm signing off on this discussion! I'm over it!
Alphie75, if you want any more advice, PM me!
Seeya!