|Alfa Romeo GTV6 Site:
European Car Magazine - GTV6 Project
European Car Magazine - January 1995
Author - Paul Mitchell
Photos by Brendan Lopez
When considering an affordable exotic, particularly one that is to be driven daily, ease of maintenance and reliability are primary concerns. This project car, a 1983 Alfa Romeo GTV-6, was selected for these very reasons.
But let's not forget what all of us think of first - performance. With 154 horses available and its 2800 lb distributed evenly between the front and rear wheels, a lack of performance is usually not a problem. Though the GTV-6 has a loyal following of those who are more than satisfied with their cars as they came from the factory, there are some who prefer to maximize the reliability and performance of their cars.
But what specifically are the GTV-6's areas of concern? And what can be done in the way of improving reliability while increasing performance?
This article is the first in a series that will answer these questions, provide you with solutions to remedy the few weak points for trouble-free miles operation and substantially lower maintenance. All of this will be accomplished using mostly Alfa Romeo factory parts.
For the mechanical and technical support of this series we've relied on Omega Motorsports in Culver City. The owner, Rex Chalmers, has been responsible for some of the fastest and most successful race Alfa engines in the U.S., and he is relied upon by many to properly maintain their street Alfas. In his years of service Rex has seen most every type of Alfa problem and is a veritable fountain of knowledge on their maintaince and modification.
Also providing many of the items used in this article, and a source every Alfa owner should know about, is Alfa Ricambi in Glendale, California. Alfa Ricambi has been the premier source of factory and afterrnarket parts in the United States, and they also market the Shankle performance products line for Alfas.
Their components are equally at home on the street as they are on the track. Since Affa Ricambi purchases many of their parts in Italy direct from the original equipment manufacturers, expect big discounts over dealer prices.
The procedures we'll cover will usually be well within the ability of the owner motivated to service his or her own car possessing and proficient with a good set of hand tools. No special tools are required, though I recommend the purchase of the Tensioner Holding Tool, Alfa part number A.2.0363 for $30, and Cam Turning Tool, Alfa part number A.2.0361 for $50. Both are available through Alfa dealers or Alfa Ricambi. Instead of the tensioner tool, a steel rod of 4.5 mm approximate diameter and at least 45 mm in length (a number nine wire drill will work) may be substituted, although I recommend spending the extra few dollars for the tool. Also, I can cannot stress how important it is to have the factory service manual. Buy it, use it, keep it. Do not do this yourself without it. The manual is also available through Alfa dealers and Alfa Ricambi for about $75.
As most GTV-6 owners can attest, the problems are few, but those few can be aggravating. They can lead to increased frequency of maintenance, mysterious oil leaks (including into the coolant, causing your car to overheat), and slipped timing belts (here the overheating is from the owner seeing the repair estimate if any valves were bent).
Timing Belt De-tensioner First on the check list has to be the timing belt
de-tensioner, a roller about 2 1/2 inches in diameter with a mounting and a series of
three springs and a piston operated by engine oil pressure. Its purpose is to compensate
for the expansion of the aluminum block and to provide more tension when transitioning to
lower rpm, when the belt is more likely to slip. If a fixed tension belt were used, as the
block expanded the belt would tighten. So a looser belt is fitted and the de-tensioner
provides more tension at cooler temperatures. Once warm, as rpm decrease, so does oil
pressure acting on the piston, relieving pressure on it and the spring it acts on, thereby
again increasing belt tension.
The entire assembly resides under the plastic timing belt covers at the front of the engine on the right side beneath the distributor drive cog. From this relatively hidden position it can do what it's notorious for, which is squirting oil indiscriminately over the entire front of your engine-in turn saturating your perfectly good timing belt and raising the odds substantially of it skipping and bending your perfectly good valves.
Previous to last vear, GTV-6 and Milano owners had little recourse but to replace the de-tensioner every time they replaced the timing belt at the factory recommended 30,000 miles, adding another three hours of labor and an additional investment in parts. Just so it could start leaking again on your new belt.
Several companies and individuals offered remedies, but with the exception of the re-worked tensioner offered by Sperry Valve Works, none were a permanent fix. The solution came with last year's introduction of the 164 four-cam. Its engine (essentially the same as the GTV-6 but with new 24-valve four-cam heads) was equipped with a redesigned de-tensioner. This new unit loses the oil pressure-operated piston in favor of two bimetallic springs, closing the oil passage from the block and eliminating any chance of oil leakage. It is available through Alfa Ricambi or your Alfa dealer for about $75.
It is a direct replacement for the original unit on any Alfa V-6. This has proven to be the solution every Alfa owner has hoped for. These units are so reliable that no one contacted has seen a failure yet and they should last indefinitely, proving that the new unit is much more up to Alfa engineering standards.
Problem Two: Head Gaskets
We have seen a recurring problem on GTV-6s and, to a lesser degree, on Milanos with the
original type head gaskets. This problem is the leakage of oil from the oil passages
delivering oil under pressure from the block to the heads. These passages are sealed with
separate 0-rings that are part of the multi-piece head gasket assembly. These 0-rings
fail, allowing oil under pressure to seep into the adjoining water jacket, contaminat ing
Rex of Omega Motorsports says the most common cause of o-ring failure is due to the owner not changing the oil often enough, allowing hydrocarbons to build up in the oil. These hydrocarbons attack the 0-ring material, causing failure. Occasionally, he has been able to trace the cause back to the time of purchase when the dealer failed to re-torque the heads as required in the pre-delivery inspection. Consequentially, the problem usually surfaced just after the warranty expired.
When owners speak of head gasket problems on their V-6s, this is what they're referring to. A failure resulting in combustion chamber leakage is exceptionally rare.
This problem with the 0-rings will make itself known to the astute owner who removes the coolant reservoir cap and finds what appears to be a chocolate milkshake residing on the bottom cap and on the surface of the coolant. Should this unlucky person also find the dipstick enjoying this milkshake and the oil filler cap too, immediately complete or have done the following head gasket remedy, because this isn't your engine cooling down with a chocolate frosty, but rather is water in your oil. Which is none too good for bearings, oil pumps and the like.
Luckily, this is a fairly rare problem, and in 98% of the cars with failed 0-rings it's nothing more than a few cc of oil in the coolant. Some bold (or broke) individuals have even been known to drive their cars in this condition for years, though I would not recommend it.
As bad as all of this sounds, the cure is relatively simple-retrofitting of the one-piece head gaskets available through Alfa dealers and again through Alfa Ricambi. These are easily installed and require no modification. Also, in the head gasket sets available through Alfa Ricambi, the factory head gaskets have been replaced with gaskets from Goetz, which everyone agrees are superior. All other seals provided are more than adequate. Of course, while the heads are removed, all seals and gaskets involved should be replaced with those provided in the kit.
The fitting of the newer type head gasket definitely improves the reliability and will last far longer than the original gaskets. But while the heads are off, why not a permanent fix? For $55 the Shankle "Sure Seal" kit does just that. It's a small price to pay for complete peace of mind. Available through Alfa Ricambi, it's a very worthy modification. It consists of several threaded unions and lengths of oil line.
An oil passage plug at the back of each head is removed and the unions are threaded in. The original oil passages in the block and the heads are blocked off by tapping, then threading in Allen screws. The oil pressure sending unit is removed and a T-union is installed-one passage for the oil pressure sending unit and another for supplying the two oil lines-one to each head.
Properly installed, it will significantly increase your car's reliability, to the point where you'll never have to worry about 0-ring failure again - you no longer have any.
In this article Rex has fabricated our own stainless oil lines, but otherwise the modification is identical. Should you prefer this too, it is available through Omega Motorsports.
The removal of the heads is a fairly simple and straightforward operation. Here we will cover only points which are specific to servicing the GTV-6 and out of the norm. We expect that you'll be knowledgeable of basic mechanical procedures before attempting this. You should have available the previously mentioned tensioner holding toot A. 2. 0363.
Begin by rotating the crank so that the P index on the crankshaft pulley lines up with the referedce pin on the front cover and the indices on the cam pulleys are pointing 45 degrees up and to the center (underneath the removable round covers on the belt cover) indicating TDC.
Next, after draining the coolant and removing the radiator, you will have to remove the brake vacuum booster to free the left head. This is done by unbolting the pedal-box assembly. Its bolts are located on either side of the steering column against the firewall under the dash. It will then lift upward and forward in the engine compartment. After having previously un-bolted the master cylinder at the booster, it can be moved forward to allow the booster and pedal box assembly to be lifted out. This can be accomplished without un-doing the brake lines at the master cylinder.
The remainder of the removal procedure is a straightforward process of removing all of the fuel-injection hoses and plenum, airbox, belts and belt cover, cam covers, thermostat assembly and distributor.
Removal of the timing belt involves retracting the de-tensioner and inserting tool A. 2. 0363. Slacken the nuts securing the body of the tensioner to the block. Then rotate the tensioner upward and lock it in position by tightening the nut previously loosened. The belt may now be removed by sliding it off the cam pulleys first.
Now remove the tensioner body and its backing plate and spring. Also, before lifting off the heads, remember to extract the intermediate gear driving the distributor and oil pump from the right head. If your car was fitted with the original type head gaskets, remember to remove the flame-proof rings atop each cylinder liner and check for the o-rings, which may still be on the block. You'd be surprised how many people either have not known or forgotten to do this, but not as surprised as they are when their new head gaskets won't seal.
Installation of the heads is essentially the reverse of disassembly, with the heads torqued to 57.9 ft-lb (78 Nm). After assembly and 500 miles of use, retorque to 65.1 ft-lb (88 Nm).
You'll find the factory service manual invaluable for these procedures. Also, be sure to follow the instructions for installation provided with the new 164 four cam de-tensioner very closely. They are slightly different than those for the original type de-tensioner. Failure to follow these instructions will result in your new belt skipping.
Installation of the Shankle "Sure-Seal" kit while the heads are removed is a
simply matter of following the instructions provided. The tools required are: 1/8",
11/32", 7/16" drills; 1/16"NPT, 1/8"NPT and 1/4"NPT pipe taps.
Alfa Ricambi also sells the above tools as the "Sure-Seal Tool Kit."
Valve adjustment and cam installation should be done only by closely following the factory service manual. The procedure is not terribly difficult, but is fairly long and is best described in the factory manual. I won't attempt it here. The required valve adjustment shims are available individually or as a set from Alfa Ricambi or your Alfa dealer.
Basic Performance Modifications
Though the G'TV-6 has ample horse power and no one would call it a slouch, its engine and chassis are far from their design limits. Inviting us further is the relative ease of servicing, an abundance of performance proven in SCCA club racing and the Firehawk series, and affordability of these parts when compared to those available for cars of comparable performance. Also, most of us just like to go faster. That's usually reason enough.
The search for increased performance must always come to one point-increased breathing. An engine is essentially just an air pump. The larger the volume of air you can move through it in a fixed period of time, the higher the specific output you will receive. It is here that we decided to focus.
Afier the removal of the heads, we decided to consult with Mike Sperry
of Sperry Valve Works. For those who follow Alfas in competition, Sperry Valve Works is a
very f'amiliar name. They have produced more competition Alfa :neads than any other source
in North America. Renowned for the quality of their workmanship, no other shop has spent
as much time flow-bench developing Alfa heads.
'I'here are 4 stages of preparation available for Alfa V-6 heads and five for the 4 cylinders. 'I'hese stages are marked by the difference in oversized valves installed. Except Stage 1 which is a standard head prep with no modifications, all stages are ported and polished the V-6's with full radius cut seats. Sperry also offers cams, a redesigned de-tensioner, a connecting red prep service and a very informative video covering available services, head design and modifications. Every Alfa owner should own this video, if' only to see why you should think twice when "Bobs Fine European Auto and Lawn Mower Repair" offers to do your head for half of what a reputable shop asks.
We finally decided on a Stage 2 head preparation which includes stock valves, full radius cut seats, porting and polishing, match porting of the intake runners, silicone alurninum-bronze valve guides and Viton seals.
The remainder of the intake tract is quite efficient, including the
original large intake airbox and filter, which is equipped with a ram air duct. Available
from Sperry but at this time not installed are new intake runners with an approximately 50
percent larger inside diameter and a matching modified plenlum.
They are a simple bolt-on modification that removes the biggest restriction in the intake system once your heads have been ported and polislied.
To take advantage of these modifications we selectecl the new V-6 cams also available from Sperry for $595 exchange. With a lift of 10 mm and a duration of 232 at .050, they fall mid-way between 164S cams and the Autodelta cams. Fully streetable, they are hardwelded for longevity and readily meet all of our initial criteria.
Downstream, the stock exhaust system is free flowing and well designed. The standard maniifolds are more than up to the job and little is to be gained by installing headers. ers if a catalytic converter is to be us . In fact, the stock catalytic converter is the biggest restriction in the svstem. Losing the converter is not an option, and fitting a much larger converter involves fabricating a Y-pipe to bring the downpipes together into the new converter, then another Y-pipe to split them again to enter the center resonator.
That's a lot of work which might not yield the desired results. Fortunately, Alfa Heaven offered the best solution. It consists of two downpipes, each fitted with its own free-flowing catal ic converter, offering a combined total area far surpassing the original; and it has a cross-over pipe, which will increase torque and horsepower. It is a direct bolt-on replacement for the original and provides a substantial power increase.
Alfa Heaven has been a source for stock, competition, t.o.s., and re manufactured Alfa items for years.
They have also had great success with their prepared GTV-6s and Milanos in SCCA racing and the Firehawk series. They have spent considerable time developing these two chassis.
To finish off our improvements we chose the Alfa Heaven 165 degree thermostat, and to mind the fuel-in'ection store, the Alfa Heaven ECU. Ours has been mapped for mid-ranae horsepower and torque and has the stock rev limiter moved up to 7400 rpm.
The abundance of performance items available for the GTV6 is surprising. The items we've chosen a but a all fraction of what is available through the source mentioned in this series.
Due to time constraints and our deadline, we were unable to put the car on the chassis dyno. We are expecting impressive results as the car is substantially faster at both mid-range ans high rpm's. We will present the results in a following article. We will also be presenting articles on GTV-6 suspension and brake upgrades.
By reading this article, you are showing interest in your car; your investment, that will put you in good stead. By doing or having done the procedures s in this article, particularly the de-tensioner, head gasket and "Sure-Seal ' updates, you're insuring that you'll get the maximum reliability out of your Alfa. Remember, there is no substitute for regular maintenance. Change your oil and filter every 3000 miles (unless youre using synthetic oil then 10,000 or 12,000 will do with just the filter changed at 3000). The air filter should also be changed every 12,0000 miles. Failure to do these simple tasks can result in more trouble than I want to talk about here.
It is common for these cars to go 150,000 miles without the removal of heads and with only scheduled maintaince performed.