Alfa V6 into 73 Spider

adelspyder · #1 (**permalink**) 03-04-2007, 05:50 AM

Hi everyone,

About a month ago, I stumbled across the Alfa Bulletin Board, and found several posts on engine conversions involving the Alfa V6 into Spiders and GT/GTVs. What a great source of information and ideas – and I’ll be getting my brother to sign up ASAP!

He’s spent the last 3 years working on installing a 3.0L V6 (sourced from a 164) into a RHD 1973 Spider. As he wants to get the car properly registered and insured, he has to ensure that the car is properly engineered to receive approval from the State Transport Authorities. First step was to receive in-concept approval from the relevant authorities of his modifications, subject to certain engineering reviews and design parameters.

His concept (as many others who have fit the V6 have realized) was to achieve higher levels of performance for the car, and he felt that the smooth and lightweight V6 would serve as a better basis than the 2 litre. He also wanted to minimize any change to the cross member or rear firewall (any welding or modifications would require certification of the work performed), improve upon chassis strength, suspension and braking to handle the extra power, and to potentially modernize the car with added niceties such as power steering (and possibly air conditioning). In keeping with the Alfa tradition, he would be trying to do all of this with original Alfa parts, and saving weight wherever possible.

He has given me some photos with a brief explanation of each one, so I’ll be putting some of these up as time allows over the next few days. While they’re not as pretty as some of the other conversions out there, he’s still finalizing all of the components for fit and installation. After this, he’ll focus on rebuilding the engine, gearbox, interior, etc.

I hope that these posts help anyone else contemplating the conversion - any questions, comments or suggestions are welcome!

Dino

adelspyder · #2 (**permalink**) 03-04-2007, 06:28 AM

Only modifications to engine bay (so far!) is the manufacture and fitment of engine mount plates, the rolling back of the tunnel lip and the removal of the top control arm lip (plate to be welded – this was necessary to provide for greater exhaust clearance). Although not required for the engine fitment, the original dual master vac setup was replaced with a LHD firewall mounted hanging pedal setup from an Alfa Milano/75. This allowed a reduction in overall weight, and would simplify the fitting of a chassis stiffener (the original RHD setup has the clutch and brake master cylinders mounted on the chassis rail).

The LH and RH engine photos show the manufactured cast aluminium bell housing. A cast unit was made to bolt the V6 to the (enhanced) standard gearbox, as excessive welding of an adaptor to a standard 2.0 L bell housing resulted in the build up of thermal stress [which requires distressing by a T5 or T6 tempering process] and distortion [which would require re-machining of the welded unit]. Consequently the welded bell housing was used as a mould, allowing the sand casting of a new aluminium bell housing, which would then be heat treated and machined to spec. The bell housing has been modified to allow the use of a SAAB 9000 clutch slave unit and the more compact 164 starter motor. Extractors are made from seam welded mandrill bent 1 5/8 steel tubing.

The RH engine photos show the fitment of 164 permanent magnet gear reduction starter motor (lighter and more compact than 75/milano unit). Custom made distributor (for bonnet clearance) using 164 cap and rotor. The distributor is a 2 piece unit where the distributor cap is mounted on a removable adaptor which is screwed on the distributor body. This design allows for the removal of the rocker cover (for adjustment of valve clearance) without removal of the distributor unit. A Nissan RB20 optical pickup will be used as this will allow for the use of sequential fuel injection.

adelspyder · #3 (**permalink**) 03-04-2007, 06:50 AM

While several people have install a V6 into a Spider, the job is more difficult in a RHD car, as the transmission tunnel is offset to the RH side to allow for space for the steering box in the LHD cars.

As the 164 engine was not installed vertically (but slightly rolled over to fit the engine bay), the decision was made to roll the engine on the crank centerline to improve exhaust clearance in the engine bay, and to reduce the overall engine height. The first photo bast illustrates the transmission / engine setup, including the roll of the engine.

RH Exhaust Photos (with and without extractors fitted) display that the rolling of the engine on the crank centreline (reverse to 164 setup) allows for No 3 exhaust port to clear steering box (factory engine and transmission tunnel is offset approximately 30 mm to the RH side of the car). Modified Milano/75 brake booster has approximately 15 mm clearance to cam cover. Although not clear in the photo, the booster is mounted above the lower lip of the cover. Thus on engine torque roll, the engine will move under and away from the cover.

The final photo shows a front perspective of the distance from the pan rail to the cross member. This can be compared to the relay (25 x 25 mm – black object on RH side of block). There is an additional 5 mm gap between the relay and the bottom of the block. Next stage is to fabricate a pattern in order to cast a new aluminium sump to fit the V6 engine and the lower shape of the 2L in order to fit the shape of the cross member.

adelspyder · #4 (**permalink**) 03-04-2007, 07:03 AM

RH engine bay front and RH engine bay photos: Alfa 33 16V accelerator cable used, along with larger aluminium Milano/75 radiator and fan. Custom made air cleaner box can be seen on LH side of car (grey). Engine has approximately 15 to 20 mm clearance from RH cam belt cover to bonnet.

LH engine photo: Note fitment of mechanical tacho drive adaptor on rear of LH head where previous 164 distributor mounted.

Transmission under car photo: Custom made drag link made for extra engine clearance (20 mm clearance from LH engine block to drag link at full lock – standard steering arm ratio). Modification of gearbox drive mount (insertion of 2 mm bushes and re-drilling of the holes) allows for the use of the stronger driveshaft doughnuts (as per Alfa Sei, BMW 5 series, Pontiac GTO / Chevy Lumina / Vauxhall / Holden Monaro / Commodore), without modification of the existing tunnel.

**Dan Walker** · #5 (**permalink**) 03-04-2007, 09:58 AM

Quote:

Originally Posted by adelspyder

RH engine bay front and RH engine bay photos: Alfa 33 16V accelerator cable used, along with larger aluminium Milano/75 radiator and fan. Custom made air cleaner box can be seen on LH side of car (grey). Engine has approximately 15 to 20 mm clearance from RH cam belt cover to bonnet.

LH engine photo: Note fitment of mechanical tacho drive adaptor on rear of LH head where previous 164 distributor mounted.

Transmission under car photo: Custom made drag link made for extra engine clearance (20 mm clearance from LH engine block to drag link at full lock – standard steering arm ratio). Modification of gearbox drive mount (insertion of 2 mm bushes and re-drilling of the holes) allows for the use of the stronger driveshaft doughnuts (as per Alfa Sei, BMW 5 series, Pontiac GTO / Chevy Lumina / Vauxhall / Holden Monaro / Commodore), without modification of the existing tunnel.

**silverspider** · #6 (**permalink**) 03-04-2007, 01:20 PM

Ditto. Cool!

87Sprint · #7 (**permalink**) 03-07-2007, 10:10 PM

thirded!

very interesting to see - keep it comin

**alfaman** · #8 (**permalink**) 03-08-2007, 09:32 AM

i know nothing about this type of conversion, but i met someone who had it done...looked great

i think the only compaint he had with it is that the tires "screetched" whenever he stepped on the gas upon takeoff....no matter how lightly he hit the gas

maybe he's lurking on the board somewhere and can comment

adelspyder · #9 (**permalink**) 03-13-2007, 08:15 AM

Good comment about potential traction issues. My brother already commented that under heavy throttle with the previous 2L he could trigger wheelspin!

While he has initially engineered the drivetrain to retain the original mounting points for the spider's 'box and the live axle, he is currently thinking how he could efficiently get the additional power of the V6 down to the rear wheels.

If your friend has done the V6 conversion into the Spider, could you advise if he has modified the rear suspension and/or diff gearing to compensate for the additional power gained and improve rear traction?

Any thoughts or comments would be most appreciated from the BB members.

Dino

**streetfame** · #10 (**permalink**) 03-13-2007, 11:42 AM

Dino,

A way to improve the grip/traction from the rear would be to lower the rear roll center via a Watts Link or Panhard Bar.

Talk to Max at Alfaholics

http://www.alfaholics.com/racing_and...nt_128_117.php

or Andy at Performatek. (scroll half way down)

http://www.performatek.com/frOnlineCatalog.htm

Also, it would be a good idea to upgrade tire and rim width over stock.

streetfame

slyalfa · #11 (**permalink**) 03-13-2007, 06:29 PM

Any chance of more bell housings? if you have a cast. make more........
and what was enhanced in the gearbox

adelspyder · #12 (**permalink**) 03-15-2007, 07:45 AM

Quote:

Originally Posted by slyalfa

Any chance of more bell housings? if you have a cast. make more........
and what was enhanced in the gearbox

slyalfa · #13 (**permalink**) 03-15-2007, 12:09 PM

OK so the normal trany mod that they all NEED

I did that on my spider. The Verde will get that if I ever have the time to pull it. but I have also been looking at a vett 6speed for the Verde...

I like that light PM starter. I have one on my spider. I had to have a custom gear put on, A 10tooth to mate with my 72 ring. but man the starter is powerfull and very light. and the current draw is very low. my old starter would only start with a 1000cca battery and was very slow.

If I could get a bell I think I would do my 72 spider. I was thinking of welding one up but at the same time thinking I might look at a better trany with 6 gears. my 72 revs the crap out of the 4cyl, and with a 6C it would just wast a ton of gas. I guess the taller rear would be the sane thing. any guess at the price for one if you do make more?

But it seems the alfa gearbox even with the light gears and all new parts still shifts slower then any other tranny.
It seem a shame that I can shift all 5 gears on my 84 truck faster then one gear on a Alfa sports car.

Craig_m67 · #14 (**permalink**) 03-16-2007, 06:19 PM

stunning. I'll take one sand cast v6 to 105 g'box bellhousing for my next duetto, thanks

more pics !!

adelspyder · #15 (**permalink**) 03-20-2007, 06:10 AM

Slyalfa,

At the time of fitting the engine into the Spider, I remember discussing the gearbox options with my brother. While his research had his first preference as a Getrag (a smaller overall size than a ZF would mean little or no trans tunner mod's, and the Getrag had many different gear options available too), it was the overall price here in Oz that put him off. Just sourcing a used 'box would be around $700, then the better gears would be another $1300, then the rebuild costs, and then making the bellhousing on top of all of this!

As a result, he thought that he might as well use the Alfa box, as the gear ratios overall weren't that bad, the boxes are fairly readily available and the parts reasonably priced (he could still rebuild the box twice over for less than the price of a single Getrag). And if the box ratios really weren't that good, then he'd know what to try next.

How much wo