Well guys my 86 GTV6 is now inside for its winter sleep and I am starting my plans for a complete engine teardown and rebuild.Engine is a 2.5L and has somewhere ? more than 150k miles on it.Runs great but valve seals are due and wet compression is a little low so I've decided to go for it.Could those of you with some experience check my list and let me know if I'm missing anything.Obviously there could be hidden surprises but I'm keeping my fingers crossed.
I'm tempted to use Greg Gordon's trick and keep my piston's and liners by rotating 90 deg. but will wait to see what they look like.Rings will be Total Seal.
If I hadn't read so many horror stories about Sperry I would be tempted to send my heads off to them but being in Canada it's a little difficult to chase things along and I don't want to find myself without heads come April.
-Timing Belt
-Tensioner
-Water Pump
-Complete Gasket Set
-2x o-ring camshaft
-2x Camshaft seal
-Front crankshaft seal
-Rear crankshaft seal
-Valve Guides-Seals Valves
-High rev springs
-Intake valves
-Exhaust valves
-Valve stem seals
-Valve guides exhaust
-Valve guides intake
-Pistons/ Liners/rings
-Crankshaft bearings
-Connecting rod Bearings
Thanks
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Little Italian
- Silver
- Posts: 4
- Joined: Sat Dec 04, 2004 6:34 pm
- Location: Lexington, Kentucky
Rebuild parts list
Looks like a good list. I've done it twice. If you buy a full gasket set, you'll find most all of the cam seals, guide seals,injector seals and gaskets you've listed are included. The full sets are expensive but have alot. Stay with a hydraulic tensioner if you can. They are very rebuildable. The kits are about $24.00 (U.S.) I rebuilt mine every time I replaced the timing belt at about 25,000 mile intervals. Get new plugs, wires, rotor and cap -plus the plastic wire holders that fit into the top of the cam belt cover. The motor mounts are good if there not spongy from oil contamination althought I understand there are some polyurethane versions out there now. I'd put new donuts in too as you've got to take the driveshaft out. Time for a good paint job on the driveshaft. I've never heard of reversing the pistons, not sure I'd try that. May be some offset side to side. I have the ALFA gtv-6 inspection booklet that shows all the tolerances. I can scan some pages for you if you email me your address and have interest (bitmaps or jpegs). Polish the crank journals with a couple of feet of emery available from a autoparts store. You need new Rod and main bearings too. Look at the colored splashes of paint on the counterweights of the crank. They are red and/or blue. That tells you which bearings to use. If you've changed the oil regularly, you won't have to go to an oversize bearing and can order the correct tolerance bearing shells. They come in packages of two (one journal) in Fiat/Lancia/Alfa packages. I ordered mine from "Alfa Parts" on the web. Or you can get Vandevell rods and mains and thrust washers. You may need a Lock tab set.
I pulled a friends motor apart last summer. It was out of his wifes Milano and had more than 100,000 miles on it. The pistons were in excellent shape and still had the fine machining ridges on the side skirts of the pistons. I intend to reuse them because they looked so good. George is an ALfisti of many, many years and I'm sure he took good care of oil changes. He gave me the engine. Good friend!
Goodluck!
Bud Feigel (bryant.feigel@att.net)
I pulled a friends motor apart last summer. It was out of his wifes Milano and had more than 100,000 miles on it. The pistons were in excellent shape and still had the fine machining ridges on the side skirts of the pistons. I intend to reuse them because they looked so good. George is an ALfisti of many, many years and I'm sure he took good care of oil changes. He gave me the engine. Good friend!
Goodluck!
Bud Feigel (bryant.feigel@att.net)
I second the hydraulic tensioner rebuild. I put a rebuilt oil-fed in with the recent head work. Piece of mind for me. YMMV.
Below is a post from the AD a while back on a tensioner modification from Fred DiMatteo regarding the seal. Hope it helps someone. It's complicated but should get rid of the leaks once and for all...
Credit to John Hertzman who posted it as a reprint from an AONE/AROC tech article some years ago. Maybe this should go in the tech docs here on the site.
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In our original article on rebuilding the detensioner (see the March 1990 issue of Velocissima) Fred and I mentioned a modification to the bushing or sleeve which provides a bearing for the piston shaft of the tensioner. This sleeve is pressed into the bottom of the cylinder of the tensioner and has an internal groove to retain the U-shaped seal which seals the piston shaft against the internal oil pressure. Since the original article we have had numerous inquiries about this modification so here is a description of the procedure.
Using a press or a large vise and appropriate socket (I use an old valve guide) push the bushing out of the cylinder. The OD of the bushing is 0.6776 and it's an interference fit in the cylinder. Note that there is an O ring which provides a positive seal between the bushing and the cylinder. If you have never removed the bushing, this is the extra O ring which comes with the Alfa rebuild kit that you could never find a place for. The standard U seal for the shaft is 8mm ID. 14mm OD and 4mm thick. It doesn't seem to last very long and has been one of the main sources of oil leaks. Fred found that the seal used in the 105 series cars mechanical tachometer drive is 8mm ID and the sealing lip is spring loaded which is not the case for the original seal. Unfortunately, however, the tach seal is 16mm OD and 7mm thick, and the OD of the bushing is not large enough to bore out for the new seal. A little research at the local bearing companies showed that this is the smallest spring loaded seal available for the 8mm shaft. So the modification we made was to chuck the bushing in a lathe and bore it out to 0.600" diameter and 0.266" deep. Bore from top side. Diagram in inches.
The next step is to get one of the 8X1 6X7 seals from your local bearing supply house and make up a mandrel so you can center it up in a lathe to turn down the OD of the seal to 0.599". 1 used a quarter inch shaft and a couple of conical washers to center the seal. You will find that the seal has a steel body onto which the rubber is bonded and you will just hit the steel at the desired diameter. This leaves the bushing with about a 1/32 inch wall thickness The seal should now be a light press fit in the bushing and a little blue locktite ensures that it stays in with no leaks. (Be sure to place the new "O" ring under the bushing)
For reference, here are the "O" ring dimensions (ID X cross section in mm) used in the tensioner; Piston 31 X 3.5; oil return rear bracket 9 X 2.5; pivot shaft-rear-9 X 1.7; pivot shaft-front 8 X 1.7; idler bearing shaft (2)14 X 1.7; piston shaft bushing seal 17 X 1.7.
So far, we have had good luck with this mod but it is not a step that is easily reversed; Alfa won't sell you a new bushing so it's not easy to go back to the original configuration. The timing belt ought to be replaced by, at the most, 40,000 miles and that is the time to check the tensioner. Incidentally, we checked the availability of the double row ball bearing used in the tensioner; it is an SKF made in Italy, not exported to the USA. Alfa gets about $150 for this gem! NOTE: Air tests show no leaks at 80O psi!
Below is a post from the AD a while back on a tensioner modification from Fred DiMatteo regarding the seal. Hope it helps someone. It's complicated but should get rid of the leaks once and for all...
Credit to John Hertzman who posted it as a reprint from an AONE/AROC tech article some years ago. Maybe this should go in the tech docs here on the site.
------------------------------------------------------------------------
In our original article on rebuilding the detensioner (see the March 1990 issue of Velocissima) Fred and I mentioned a modification to the bushing or sleeve which provides a bearing for the piston shaft of the tensioner. This sleeve is pressed into the bottom of the cylinder of the tensioner and has an internal groove to retain the U-shaped seal which seals the piston shaft against the internal oil pressure. Since the original article we have had numerous inquiries about this modification so here is a description of the procedure.
Using a press or a large vise and appropriate socket (I use an old valve guide) push the bushing out of the cylinder. The OD of the bushing is 0.6776 and it's an interference fit in the cylinder. Note that there is an O ring which provides a positive seal between the bushing and the cylinder. If you have never removed the bushing, this is the extra O ring which comes with the Alfa rebuild kit that you could never find a place for. The standard U seal for the shaft is 8mm ID. 14mm OD and 4mm thick. It doesn't seem to last very long and has been one of the main sources of oil leaks. Fred found that the seal used in the 105 series cars mechanical tachometer drive is 8mm ID and the sealing lip is spring loaded which is not the case for the original seal. Unfortunately, however, the tach seal is 16mm OD and 7mm thick, and the OD of the bushing is not large enough to bore out for the new seal. A little research at the local bearing companies showed that this is the smallest spring loaded seal available for the 8mm shaft. So the modification we made was to chuck the bushing in a lathe and bore it out to 0.600" diameter and 0.266" deep. Bore from top side. Diagram in inches.
The next step is to get one of the 8X1 6X7 seals from your local bearing supply house and make up a mandrel so you can center it up in a lathe to turn down the OD of the seal to 0.599". 1 used a quarter inch shaft and a couple of conical washers to center the seal. You will find that the seal has a steel body onto which the rubber is bonded and you will just hit the steel at the desired diameter. This leaves the bushing with about a 1/32 inch wall thickness The seal should now be a light press fit in the bushing and a little blue locktite ensures that it stays in with no leaks. (Be sure to place the new "O" ring under the bushing)
For reference, here are the "O" ring dimensions (ID X cross section in mm) used in the tensioner; Piston 31 X 3.5; oil return rear bracket 9 X 2.5; pivot shaft-rear-9 X 1.7; pivot shaft-front 8 X 1.7; idler bearing shaft (2)14 X 1.7; piston shaft bushing seal 17 X 1.7.
So far, we have had good luck with this mod but it is not a step that is easily reversed; Alfa won't sell you a new bushing so it's not easy to go back to the original configuration. The timing belt ought to be replaced by, at the most, 40,000 miles and that is the time to check the tensioner. Incidentally, we checked the availability of the double row ball bearing used in the tensioner; it is an SKF made in Italy, not exported to the USA. Alfa gets about $150 for this gem! NOTE: Air tests show no leaks at 80O psi!
The true joy of an Alfa Romeo is behind the wheel.
Thank you Bud and Peter.Bud you description is excellent.Makes me wish you were my next-door neighbour ! Fortunately I have a great deal of documentation on hand so I have all the component specifications and will check them all as if I was a Swiss watchmaker.I have run the mechanical tensioner for about 40k miles with no problems so I am hesitant to pull out my old hydraulic one and rebuild it.Somehow I've convinced myself that the failures of the newer one result from a poor design which requires following the instructions 100%.The slightest deviance from these directions could result in failure.I'll read and re-read Peter's procedure from Fred D and make a decision.Pretty much like going to a Casino ! Greg Gordon and others have mentioned the trick of rotating the piston liners (I erroniously said "pistons" in my post) 90 deg.and just installing new rings.Sounds very attractive financially but I'll give this some more thought.
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Greg Gordon
- Verde
- Posts: 1552
- Joined: Mon Nov 29, 2004 7:06 pm
Hi Murray,
Your list and the additions others suggested are excellent.
The gasket set from IAP has all the seals we just used one on the Verde build, strangely the one I got from VICK didn't. I probably would not buy new intake valves since they are probaly in good shape. Have them reground and they should be fine. Alfa's valves have plenty of extra metal on them to allow this. The exhuast valves tend to be more worn but could be re usuable.
Rotating the liners 90 degrees works, and provided the liners are not out of spec to begin with it's just about as good as buying new liners. Keep in mind we have actually done this twice and one of the engine has well over 100,000 miles since we did it and it's still going very stong.
I usually don't comment much on the timing belt tensioners since I think both designs are prone to failure. I have never had a belt slip and I use the mechanical tensioner, but I may be just lucky. Of course as anyone who visits page 6 of my site will discover I no longer need to fear belt slippage anyway.
I suggest you try to get Sperry on the phone a few times before you ship anything too them.
Your list and the additions others suggested are excellent.
The gasket set from IAP has all the seals we just used one on the Verde build, strangely the one I got from VICK didn't. I probably would not buy new intake valves since they are probaly in good shape. Have them reground and they should be fine. Alfa's valves have plenty of extra metal on them to allow this. The exhuast valves tend to be more worn but could be re usuable.
Rotating the liners 90 degrees works, and provided the liners are not out of spec to begin with it's just about as good as buying new liners. Keep in mind we have actually done this twice and one of the engine has well over 100,000 miles since we did it and it's still going very stong.
I usually don't comment much on the timing belt tensioners since I think both designs are prone to failure. I have never had a belt slip and I use the mechanical tensioner, but I may be just lucky. Of course as anyone who visits page 6 of my site will discover I no longer need to fear belt slippage anyway.
I suggest you try to get Sperry on the phone a few times before you ship anything too them.
Instead of stock pistons, why not go for 0.5 or 1mm overbore? Say 10:1 or 10.5:1 Venolias from Greg?
For headwork, try going to www.alfapartscatalog.com, call them and ask for Norman Racing's phone number. They also belong to the same group of companies. Norman racing is very reliable, they did my 3.0 V6's head in 3 days.
For headwork, try going to www.alfapartscatalog.com, call them and ask for Norman Racing's phone number. They also belong to the same group of companies. Norman racing is very reliable, they did my 3.0 V6's head in 3 days.
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Greg Gordon
- Verde
- Posts: 1552
- Joined: Mon Nov 29, 2004 7:06 pm
Compression Ratio Change
Increasing the compression ratio even just to 10:1 makes a lot of sense to me. It is the ratio used in the S engine. I notice on Greg Gordon's web site and in IAP's catalog that this modification probably wont meet emission standards. If the S engine does, why can't a 2.5?
Scott Shure
Ellicott City, Md
85 GTV-6
Ellicott City, Md
85 GTV-6
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Greg Gordon
- Verde
- Posts: 1552
- Joined: Mon Nov 29, 2004 7:06 pm
I don't recall saying that. It's true that in many places there are emission laws that would make it illegal to go with 10:1 pistons but as far as passing an underhood inspection or running emission test...no problem. I may have been talking about an engine as a complete package. For example if we were talking about a 10.5:1 motor with race cams it wouldn't pass an emissions check due to the cams.
Yea guys the idea of a slightly higher C.R. is appealing but I'll wait until I get a look at the pistons and liners before deciding.I'm pulling the engine tonight so it won't be long.The other consideration is if I go with Greg's SC.then higher compression would be counter-productive.
1986-GTV6
1989-75 Twinspark very sadly sold-remarkable sedan !
2014 Audi Q5 3.0l TDI - torque MONSTER
1989-75 Twinspark very sadly sold-remarkable sedan !
2014 Audi Q5 3.0l TDI - torque MONSTER
Depending on how high a CR you want to go, you could find a 3.0 bottom end and put your 2.5 heads on it. You end up with 12:1 compression though.
You can take 0.040 off the heads for another point of compression without changing pistons. That'll get you to about 10.5:1 which is what I did in my car.
-Peter
You can take 0.040 off the heads for another point of compression without changing pistons. That'll get you to about 10.5:1 which is what I did in my car.
-Peter
The true joy of an Alfa Romeo is behind the wheel.
Milling .040
Can you just mill the head that much? Do the pistons need valve pockets? How is reliablility?
Scott Shure
Ellicott City, Md
85 GTV-6
Ellicott City, Md
85 GTV-6