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Tech QuestionsOctober 2001 Tech Q & A

Answer by Technical Editor Rex Chalmers

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October Topics:

GTV-6 Front End Stiffening | Piston Rings, Liners, and Compression | Motronic Power Increase
Overheating 2 Liter | Low RPM Rattling Noise

GTV-6 Front End Stiffening : question by Paul Grant | ’86 GTV-6

I've heard both pro and con about firming up the front suspension of my GTV6. I currently have a Verde front roll bar. My mechanic in ABQ, NM insists that stiffening up the front end will tear up the front end of the car. I was thinking of Shankle anti roll bar and poly bushing for the caster rod. Your thoughts and any other place to purchase performance suspension parts for the GTV6 other than Ricambi?
Answer : Anytime the front end of a chassis is made stiffer more stress and impact shock will be transferred to the chassis. Generally, the lower ball joints will take the brunt of the abuse. 105 and 115 chassis also have a problem with their sub-frames cracking as well as upper shock mount concerns. 116 &119 chassis have problems with cracks and weld separation at the upper shock mounting frames and a major problem with the sheet metal at the sway bar mounts. The sheet metal cracks and sometimes actually separates from the chassis. I have seen this problem even on bone stock front suspensions.

There is a cure. Alfa Ricambi supplies re-enforcing plates that are of a heavier gauge steel that mirrors the sheet metal under the front sway bar mounts. These plates require welding into place, so take them to a good welder for installation. I have installed many of these plates with good result.

As far as the modifications that you have in mind, I would definitely install the plates and a thicker front sway bar. Depending on your driving style and what rear springs you are using; I would also consider a more aggressive rear sway bar as well. The poly castor rod bushings are loud and can also cause some structural problems - if you feel the need for better castor control, I would consider modifying the castor arm mount to use 115 castor ball joints in place of the standard rubber discs.

Piston Rings, Liners, and Compression :

Part A - question by K Patterson | ’77 Spider
I am currently in the process of installing new pistons and liners in my 77 Spider. I have a lack of compression: 90psi per cylinder, then with a squirt of oil, 120psi. I am having a hard time getting the liners out of the block, and want to know if there are any factory tools for this process, as I do not want to risk damaging the block. I have tried pulling from above, and some gentle tapping from below with a block of wood with no luck.

Part B - question by Tony Rondeau | ’79 Spider Veloce
I am curious as to what the compression reading (psi) should be in my "79" U.S. 2.0 spider? What psi is considered to be good?

Answers :

Part A - Unfortunately, I don’t believe that the factory tool is readily available. A good machinist could make one for you. However, the type of tool that the factory provided did not work very well on seized liners. You should try heating the block at the base of the liner with propane torch and use brass or bronze drift, tap alternately on opposite sides, as liner can cock easily and jam in place. I have used this procedure countless times and have never damaged a block. I have seen liners chip and crack during this process, but I would imagine that 24 year old liners probably need replacing, so I wouldn’t worry too much if you loose a bit of liner in the removal process.

Part B - Compression test should show between 145-160 psi for a 9:1 Compression Ratio (CR) Alfa. Vehicles with shaved heads and/or carbon build up can 170 psi and over.

Motronic 4 Cylinder Power Increase : question by Victor Schuler | ’91 Spider

Is there anything (modifications) I can do to increasethe Horsepower in my 1991 Spider?

Answer : Yes, Victor, there are modifications that you can do to your engine that will increase power. First, strip off the Motronic system and install Weber Carbs and a high-energy ignition system or install a programmable fuel injection/ignition system. If that is more than you want to tackle, I would first install a chip to increase the RPM that the rev limiter kicks in and enrich the high-end fuel mixture. Then I would install a set of performance camshafts, and tubular exhaust headers. The catalytic converter also limits the speed that the exhaust gases exit the tail pipe. Basically, you can increase horsepower, how you want to do it is up to you and the depth of your pockets.

Overheating 2 Liter : question by William Gillespie | '81 Alfetta 2000

I recently bought this car for a bargain, but the previous owner complained that the car keeps over heating and then pops the head gasket. The problem occurred all at once, no mods or repairs has been done prior to the problem. In trying to resolve the problem a new water pump, thermostat and fan switch has been fitted - no results. The previous owner then recondition the head completely, new valves, guides, crack test and the head has been skimmed as well. The problem did not occur again for two months (+/- 1500 Kilometres has been traveled). The head has been re-torqued at 1000 Km , however the car overheated again, the Radiator has been cleaned. Today I once again were forced to change the Head gasket, after which the car idled nicely for about 15 min after which she started overheating again. The top radiator hose was warm however the bottom hose was cold, could you advice me as to where and what I should do next in order to repair this over heating issue.
Answer : First let me say that this is a very uncommon problem for 2.0 Alfa engines. Judging from the symptoms you have described, I would have to conclude that there is a problem with coolant circulation through the engine and radiator. A hot upper hose and a cold lower hose usually point to either a thermostat malfunction, an obstruction somewhere in the cooling system, or a radiator that is not flowing properly. First, I would test the thermostat by placing it in a pan on your stove with a thermometer in the water and note at what temperature the thermostat opens or if it opens at all. Next send the radiator to a good radiator shop and have them check the flow rate. Finally, with the engine cold and the thermostat removed, and the heater on, insert the end of a garden hose into the coolant outlet on the top of the engine and watch the flow out of the water pump, then put the hose into the waterpump outlet and check the flow out of the thermostat housing.

Low RPM Engine Noise : question by Dean Mericas | '74 GTV

I've got a peculiar noise that my engine makes, and I'm trying to get some guidance on what may be causing it. At part throttle under load, a noise that sounds exactly like valve clatter kicks in somewhere around 1500 RPM, and then goes away as the revs build past about 2000 or 2500 RPM (my tach is wildly off, so I can't be precise). It feels like there is a flat spot in the power at the same time. Once the revs go up, the noise disappears and the car runs like a champ.

I've checked the valve settings and ignition timing, and tensioned the chain. Everything seems to be right at spec. I even tried premium gas, with no apparent effect.

Answer : Assuming that the timing chain is tensioned correctly, the lower timing chain is not too loose and that the ignition timing cam timing is correct, I would check the advance curve, too much advance at low RPM can cause detonation. I assume that you aren’t trying to run a 12:1 engine on pump gas, so I would have to suspect an exhaust leak, probably where the manifold meets the cylinder head. You state that you even tried premium fuel: you should always use premium in any Alfa engine. Check your compression, the prolonged use of regular grade gas can cause carbon build up that will increase Compression Ratio (CR) and cause detonation as well.

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