I recently purchased an 82' gtv6 w/ 3.0 liter engine. I have it torn down right now to do timing belt, adjust valves, etc. My question is this. When I bring the engine to TDC on #1 cylinder my left cam lines up perfectly w/ the factory indices. My right cam (intake side) however the marks are about 1/8 '' off. What gives? Is this normal? My manual says they should both line up @ TDC. The weird part is the engine ran strong right up to me taking it apart the other night. I also havent removed the timing belt yet. Do you think Its a tooth off? Should I line it back up?
Second question. I have the mechanical tensioner on the car. I know from reading posts that most people dont trust it. That being said I cant imagine retrofiting the hydraulic one at this point. Do I have to buy a new mechanical tensioner w/ each belt change? I've read that the springs give and break. Does this happen at a certain mileage interval? Finnally I saw the staybelt tensioner that alfa heaven makes. I realize that belt wear may be a little more and it has no provision for block expansion (which I cant see being a major factor) does anyone here use this product? If so for how long has it been installed? Any other pros or cons to it?
Thanks in advance for everyones help. This forum is awsome for tech help and honest opinions. It has been invaluble to me in researching and buying my new pride and joy.
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Tommy Cooney
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- Joined: Fri Apr 29, 2005 8:39 pm
- Location: Florida USA
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MerrilGordon
- Gold
- Posts: 166
- Joined: Wed Dec 29, 2004 5:55 pm
- Location: Marysville, WA. USA
Once I had one of the cams slip a cog and could hear a ticking sound from that side. I believe the pistons were just touching the valves. I thought I was done for but a veteran alfa mechanic said they probably didn't bend and to just reset the alignment. He was right, no bent valves as I checked with a compression test. My point being that if you haven't heard anything, it likely is not off one cog, and if it was, you'd hear it. I don't remember how far off the mark was though.
A previous engine I had showed both cam marks off by approximately that much. I'm pretty confident that was due to substantial milling of the head surface. That's probably your condition. Hopefully the machine shop won't have to take much more off to clean up the surface for the rebuild. Some of these heads get milled down to get more compression and others to simply clean up the corosion that has occurred over the years.
I would imagine having both heads milled to the same height would give even compression all around. Maybe allow the engine to run a little smoother. Hopefully the problem head hasen't been machined past some minimal acceptable value. I've also read that heads that have had extensive machining are more sensitivie to heat and warpage.
Hope that helps in your diagnosis,
Merril
A previous engine I had showed both cam marks off by approximately that much. I'm pretty confident that was due to substantial milling of the head surface. That's probably your condition. Hopefully the machine shop won't have to take much more off to clean up the surface for the rebuild. Some of these heads get milled down to get more compression and others to simply clean up the corosion that has occurred over the years.
I would imagine having both heads milled to the same height would give even compression all around. Maybe allow the engine to run a little smoother. Hopefully the problem head hasen't been machined past some minimal acceptable value. I've also read that heads that have had extensive machining are more sensitivie to heat and warpage.
Hope that helps in your diagnosis,
Merril
82 GTV6 3.0
Engine
Hi Tommy,
Just briefly, my experience with the mechanical tensioner from Alfa Heaven has been disastrous. The mounting plate actually bent under tension to cause belt run off. It's now sitting on the shelf.
The solution was to make my own from the original unit. It works very well. You just need to warm the engine up to allow the block to expand out enough to correctly tension the belt before using big revs.
This issue has been discussed many times on the forum and fans of the product will tell you otherwise. I guess you will need to weigh up the pros & cons.
Just briefly, my experience with the mechanical tensioner from Alfa Heaven has been disastrous. The mounting plate actually bent under tension to cause belt run off. It's now sitting on the shelf.
The solution was to make my own from the original unit. It works very well. You just need to warm the engine up to allow the block to expand out enough to correctly tension the belt before using big revs.
This issue has been discussed many times on the forum and fans of the product will tell you otherwise. I guess you will need to weigh up the pros & cons.
Transaxle Alfas Haul More Arse
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Tommy Cooney
- Silver
- Posts: 12
- Joined: Fri Apr 29, 2005 8:39 pm
- Location: Florida USA
Ok thank you both for your replys. I just got the engine pretty much back together. I ended up doing cam seals etc. I thought that maybe it was off around 1/2 a tooth so I was planning on filing the slots in the pulleys to realign the cams. It turns out it was off 1 full tooth! Can the engine run w/o interferance 1 tooth off? It always felt strong and I never heard any unusual ticking. I ended up moving it the one tooth, put the belt on and turned it over by hand 3-4 times I didnt feel or hear any contact. So my question is should I button it up the way it is? I dont want to start it if Im going to bend valves. I look forward to any light you all may shed. Thanks Tommy.