pix
FORDMUSCLE.com FordMuscle Nav
Page
1
2 3 4
 
High on Carbs: Part II
Text and Photography by Chirag Asaravala

We left off in Part 1 without fully having our arms around the entire project. We had mocked up the Vortech blower in the '67 Mustang engine bay and were left with several uncertainties. We did not know how exactly the accessory belt routing would be configured. Other challenges included plumbing the radiator, setting up the fuel delivery, and fabricating the supercharger ducting. The good news is since then we've figured it all out, as is explained in detail in this article. We've even fired up the motor with the blower and attempted to drive the car under boost. We say attempted because at 3lbs of boost on the gauge we felt detonation and backed out. However this was expected as we are still lacking timing advance control at the time of this article. In Part III however we will deal solely with tuning issues.

Accessory Belt Routing
By far the biggest challenge of adapting the 5.0L kit to our early Mustang was in setting up the belt routing. The Vortech kit is designed to be used with a 5.0L serpentine belt system. Such a system assumes a
reverse rotation waterpump, a 5.0L belt tensioner, and accessories on both sides of the crank pulley (e.g. power steering, AC compressor, alternator and smog pump.) Our '67 was not only equipped with a V-belt system, but a standard rotation waterpump and only one accessory, the alternator. To make things more complicated early Mustang waterpumps discharge on the passenger side. While we accepted that we had to convert to a serpentine belt (necessitated by the Vortech crank pulley), for some reason we were convinced it would be easier to use the stock '67 pump. In the end we were wrong, but we'll outline our failed attempt as there is always something to be learned from mistakes.

The first sign that we were headed down the wrong patch was with respect to pulley alignment. The distance from the dampner face to the center grooves on the Vortech crank pulley is stock 5.0L dimensions. However the hub on the stock 1967 waterpump is closer towards the engine block than would be on a late model 5.0L water pump. Furthermore the early pumps being standard rotation requires that you use a grooved waterpump pulley. We could not use a late-model Mustang smooth waterpump pulley. Smooth pulleys are driven with the backside of the serpentine belt which means the accessory is turning counterclockwise.

Still trying to make the stock '67 waterpump work, we ordered up a grooved waterpump pulley designed for an early Lincoln.

Initial attempts to stick with the stock '67 waterpump led to belt interference and no way to tension the belt.

Final belt routing worked best with a reverse rotation 5.0L waterpump.

Use a grooved tensioner pulley, sourced from a 4 cylinder Ford.

The 5.0L tensioner is adjusted manually in this belt routing.

We had a radiator shop move the lower outlet to the opposite side - cost $80.
We used spacers behind the pulley to align it with the crank pulley. We thought we could run a short belt around the crank, alternator and waterpump, all turning clockwise. Unfortunately we hit a couple snags. First off, there was no easy way to tension the belt. Serpentine belts require proper tension to perform correctly. Usually a spring loaded tensioner maintains proper tension at all times, compensating for belt stretch and wear. In our system we could not use a tensioner as there was no place to mount it with the short length of our belt. The second problem was that the belt rubbed on the lower radiator hose. In fact it was rubbing, and this would eventually lead to a hole in the hose (see image 1).

After racking our brains for several days the solution began to appear (see image 2.) We suspected that all of our headaches could be resolved by simply using a late-model 5.0L waterpump. This pump would be reverse rotation, allowing us to use a smooth waterpump pulley off a late model Mustang. The pump hub offset would be correct and require no pulley spacing. The pump has it's outlet on the drivers side which would alleviate our belt rub issue. This solution however would require the lower port on our radiator to be moved over to the drivers side (see image 5.)

We installed the 5.0L waterpump and used a smooth, stock 1993 Cobra waterpump pulley. Anytime you run a smooth pulley in a serpentine system you must have a grooved pulley mounted higher in the pulley chain on which the belt wraps around to change direction. On a stock 5.0L engine the grooved power steering and AC pulleys are mounted higher and to the right of the waterpump, enabling proper belt routing. On our motor we have no accessories on the driver side of the block. Doing some research we came up with a solution. We took the stock 5.0L tensioner (obtained from a wrecking yard) and ground the locating pin off its back side. We then swapped its' smooth pulley with a grooved pulley from a belt tensioner off a Ford 4-cylinder engine, also from the wrecking yard (see image 3). We mounted our modified tensioner in the intended location on the Vortech bracket (see figure 4). In this configuration, however, the tensioner does not provide spring loaded belt tension. The tensioner arm is meant to tension clockwise, however in our belt routing we require tensioning upwards, or counter clockwise. To achieve this we use simply use a large wrench and pull the tensioner up until desired belt tension is achieved, then tighten the large mounting nut down. Rather than an automated tensioner it is a manual one, however it works just fine. We had this setup on the dyno at 6500 rpm and it did not slip. A new belt will stretch and thus the tension will need to be reset after first few miles.

With the belt routing finally resolved we felt as if we were over a major hurdle. Now the entire front dress could be bolted into place and the radiator and hoses dealt with. The lesson learned here - what appears to be the hardest solution may in fact be the easiest.

(Radiator mouting)
Page
1
2 3 4
 
In This Article:
We finish up installing a 5.0L centrifigual supercharger kit on to our 331 stroker equipped 1967 Mustang. The engine is fired up and test driven under boost.

Also See:
High on Carbs Part 1: Mock Up
 
 
Table of Contents
The radiator is moved back to allow clearance between crank pulley and fan. Page 2
The mechanical fuel pump is modified to increase pressure as boost rises.
Page 2
Oil system is modified to feed the supercharger and allow drainage back to the oil pan. Page 3
Air inlet to the blower and duct work between the blower and carburetor is fabricated. Page 4
The engine is fired up with the blower. Listen:

or download MP3.
 
 
 
 
 

pixblue
pixblue
Tech Archives Project Cars Readers Cars Feature Cars