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166 24v into 116 GTV

Posted: Wed Oct 03, 2007 10:51 am
by kevin
After a slow start in this years race season in the 'budget race' car as shown in race and track section , I wanted bigger and more power full motor to put into the race car. I needed something to make up for total lack of drivers skill to put me in front of the all Alfa Romeo field in the only GTV 6. Even though I am running a totally stock 2.5 12v motor ,I figured I must be ahead of atleast half the four cylinder field hence the search for a new motor.
Luck had it for me that some chap(unlucky for him) rolled his 166 (30 000KM ON CLOCK) and the motor was going very cheaply. I managed to swop a spare automatic 164 box plus other spares to this garage for this motor.
My plan was to leave this 24v motor standard and just fit some 'wilder' intake cams.
In between racing and the 3.7 project I decided to do this project as fast as possible but for some strange reason this has dragged on for the last four months. Main reason for is that I have gradually improved my driving and got my budget race car realy set up well and started getting some good results. I have also grown attached to the sound of the 2.5 12v motor and the reliability it has given me after ten hard races, many practise session and a few track days.I have no idea how many km this 2.5 12v motor has done but it just seems to rev free'r every race. Anyway the 166 engine is now finished and ready to go into the car but I want just one more race with the old motor before the swop.
I have put this in performance as I have a few interesting pics on this conversion which might help others who might try the same thing.
As the 166 had rolled my first step was to remove the heads and sump(remove journal caps) to have an inspection that nothing major had happened to the engine.
All looked perfect so next step was to send the intake valves in for lenghtening this time, to suit the new higher profile cams. The valves and cams were done by SA's leading motorsport team( BMW). The valve seats remained constant(measuerd clearances before) so the lenghtening of each valve was the same if that makes sense. On went new head gaskets with new tensioners,belts and waterpump . The 166 tensioner is a pleasure to work with and twenty mins later with cam blocks all is done.

Posted: Wed Oct 03, 2007 10:53 am
by kevin
The standard GTV thermostat housing was to be used but it is not simple as on 164 conversion as the bottom of the thermostat housing 'ears ' had to be cut off and rewelded to suit the 166 waterpump.

Posted: Wed Oct 03, 2007 11:47 am
by kevin
As the waterpump sits closer to the timing belts I had to move the top thermostat housing out by a few mm for clearance even after grinding the sides of it. To move it out I redrilled the 7mm hole to 8.5mm in the centre section as shown and also bench ground it down 2mm. All this to clear the timing by 3mm which is all you need. Cant see it getting closer.
Probably notice there is no thermostat and the bottom housing is blocked with a welch plug.
Works well for me(few reasons) as our temperatures here are so high and have only seen snow once in twenty five years.With the thermostat in I was sitting at 88 deg on the start grid and after lap two the fans were running permantly on this particular track.In heavy traffic on lap eight temps were getting really high. I know I can chainge radiators with bigger fans and have the engine running at its optiomal temp 90 deg but this was the easy way and i dont have to worry if the thermostat is working properly or stuck slightly open as on my 164(daily drive).

Posted: Wed Oct 03, 2007 11:57 am
by kevin
pic of welch plug

Posted: Wed Oct 03, 2007 11:59 am
by kevin
See the grind marks on side of housing

Posted: Wed Oct 03, 2007 12:00 pm
by kevin
side view

Posted: Wed Oct 03, 2007 12:03 pm
by kevin
Next was oil filter. I had to make a choice on filters before tapping thread as the GTV and 164 have same pitch thread which I think is 16 &3/8 while the 166 is 1.5pitch. Went with the GTv filter Z96. Must check filter fastens properly againat block and insert does not extend to far inside filter and block it causing it to explode on startu ( been there and done it).

Posted: Wed Oct 03, 2007 12:04 pm
by kevin
Who needs a drill press! Sometimes got to make do.

Posted: Wed Oct 03, 2007 12:06 pm
by kevin
Tap in with a grease filled cloth inside to catch any fillings.

Posted: Wed Oct 03, 2007 12:08 pm
by kevin

Posted: Wed Oct 03, 2007 12:10 pm
by kevin
Next was sump which was made a few years ago for a 3.4motor. As you can see the sump takes 10litres oil hence reason I dont run oil cooler( is that a valid reason Mats?)
This sump profile at the rear was copied off a standard GTV6 sump. As soon as you use gta crank shaft it tends to touch the sump due to extra throw as shown and occurs on the standard sump as I have noticed on my other motor

Posted: Wed Oct 03, 2007 12:12 pm
by kevin
A 60-2 pickup sensor is used but as soon as you press the ring onto the pulley it either touches the cam belt or waterpump pully so both ahd to be machined. The pickup only needs a 3mm area so i was well within limits.

Posted: Wed Oct 03, 2007 12:26 pm
by kevin
All cam covers , plennums has been glass bead blasted on outside only to avoid any embedding of the grains into the soft Aluminium.
More pics of plennum modification to follow.

Posted: Wed Oct 03, 2007 12:40 pm
by fedezyl
Gorgeous engine my friend! i'm jealous! :D

Posted: Wed Oct 03, 2007 12:46 pm
by Zamani

Can you divulge some info about the intake cams? Better than GTA? Also is that a 3.0 or 3.2 from the facelifted 166?

I'm getting my stainless headers next week or so.

Still undecided about the pistons. Stock or overbore with higher compression. Discussing this with Mr. B.