The purpose of this upgrade is -
Increased horsepower, increased torque, increased oil pressure, increased engine cooling, increased
drive-ability, improved appearance. (It is assumed you are starting with a healthy engine).
The aim - to add performance without stripping down the stock engine. Easy DIY.
Most of the upgrades below can be done by anyone with DIY skills and a basic understanding of vehicle routine servicing.
The two exceptions are -
1. It is recommended to bring in an expert to set up the carburetor.
2. Some bending / welding will be needed to adjust the exhaust pipes. An exhaust specialist may be needed.
Easy upgrades - All of this was achieved without an engine removal and without an engine strip down. The heads were not
removed. The stock heads remained. The rocker covers were removed to assist assessment and fit. The exhaust
manifolds were removed. The carburetor was removed. The inlet manifold was removed. At the same time the opportunity
was taken to repaint the rocker covers with Chevy orange paint. The oil pan and oil pump were also removed.
Parts required -
Street Demon 1904 750cfm carburetor with optional brackets. Price £300 ($450)
Reasons for choosing this carburetor -
1. Highly recommended for high performance.
2. A very important reason is the "Aerospace Composite Bowl for significant heat insulating benefits" This composite base / pan
reduces heat conduction from the engine. Too much heat can incorrectly vaporise the fuel within the carburetor which reduces
efficiency, reduces horsepower and results in poor warm starting.
3. Compatible with the 200R4 transmission as it has a bracket attachment which is correct for the 200R4 dent cable. This results
in the transmission changing gear correctly and insures the internal pressures within the transmission are always correct.
4. Cruise control option. The carb also comes with a bracket for cruise control. However, since it was decided to include cruise
control as well, the Lokar bracket was ordered as this bracket has both the 200R4 transmission option and the cruise option.
(Note, cruise control also needs the correct option on the steering column but the steering column was also upgraded).
Edelbrock EPS 2701 Dual Plane aluminium inlet manifold. Price £120 ($180)
It is well known that dual plane inlet manifolds can increase horsepower and torque. The question is, which make and model
provides the highest performance at a reasonable price? This manifold is widely respected as offering high performance as a
very reasonable price. In reviews and tests, (e.g. www.hotrod.com tested 19 manifolds) only one inlet manifold achieved slightly
higher horsepower and torque figures and that was the "AFT Titan" composite unit at 3 times the price. In addition, with a stock
engine it is unlikely the difference would have been noticeable. The Edelbrock was painted Chevy orange (to match the rocker covers),
but the raised lettering was left silver. The Edelbrock inlet manifold is made in the USA to high quality standards of workmanship.
Carburetor notes. -
Notes on fitting and setting up the Street Demon carburetor can be found in several places on this site.
1. Fitting the carburetor - fitting.
2. Setting up the TV Dent cable.- TV cable.
3. Monitoring the transmission oil pressure - pressure gauge.
3. Fitting a throttle return spring - return spring.
4. Throttle cable and the need for a loop - Loop.
Sanderson performance "header" manifolds - £300 ($450) + £215.50 ($325) of extras.
Sanderson performance "header" manifolds were chosen for the following reasons -
If the inlet side of the engine is improved, failure to improve the flow of output gases would result in the inlet modifications not
producing the expected improvements. In a 49-53 Chevy truck, there is no space for tubular headers without major alterations to
the inner fenders to provide more space. This can also adversely affect structural integrity . Also headers can by noisy compared to a
manifold. A version of the Sanderson manifolds is specifically designed for the 47-53 Chevy truck. The left and right sides are not
the same. The outlet on the left side is offset from the centre to provide the correct amount of space for the steering shaft and
linkage. This manifold hugs the block and really no other manifold available is as close fitting. The Sanderson "header" manifolds
are highly respected for a performance very close to tubular headers but are much quieter. Reviews also state that unlike
other makes there are never any leaks of any exhaust gases. The only criticism sometimes levied at these manifolds (from those
who do not know a solution) is that they can result in the HT leads being heated to high a temperature, however, a company called
R and M Specialities makes a special bracket specially for the Sanderson manifolds which supports the leads and this problem then
does not exist. The new custom made high performance HT leads are held on a special support bracket to insure they are not
too close to the exhaust manifold. This keeps them cool. The support bracket is designed for the Sanderson manifold. The support
bracket keeps the leads away from the heat and is made in the USA. "Spark plug wire divider custom machined aluminium
brackets"- $50 (£35) from Summit Racing. New HT leads from Tayler Performance all cut to the exact correct lengths £60.00 ($90.00)
per set. (2019 Update notice in the pictures above the Sanderson header manifolds have been painted with E-Tech Extremely High
Temperature Paint. Colour - Graphite. Available from Amazon and other retailers. The manifolds were painted during the TCI IFS
upgrade in 2019. They still look perfect in 2022. This paint has not discoloured at all and is highly recommended).
Some alteration to the routing of the exhaust pipes was needed to suit the new manifold. New stainless steel pipes were used from
the manifold all the way back to the stainless steel flanges on the mufflers. In addition, 2" heat shield was wrapped round the exhaust
from the manifold until it went under the cab. This resulted in less heat being generated in the engine compartment. This is another
useful tip for keeping things cool under the hood. All of these extra parts added about £215.50 to the cost of the upgrade. In detail-
Spark plug HT leads £60. Spark plug leads support bracket £35, 2 X 1.5m of stainless steel exhaust pipe £65, Anti vibration stainless
steel flex exhaust pipe (with 4 clamps) £32 DTI Titanium heat insulating wrap (2 X 15' rolls) £19.00, stainless steel tie cables £4.50
SBC aluminium finned oil pan kit, pump, hardened shaft and oil. Price £165 ($250)
Small block Chevy aluminium finned deep oil pan £110 ($170), Melling M55 high volume oil pump £26 ($38). Melling IS55E hardened
oil pump shaft £7 ($11) ($10), oil £22 (£36). A high quality aluminium deep oil pan with high volume oil pump and good oil can increase
oil pressure. It is recommended to use a hardened shaft if a high volume pump is used. The deeper oil pan needs a couple more pints
of oil. The recommended chosen oil was the Carlube Triple R Semi Synthetic 10W-40. Although cost was not a consideration, this oil
is only about £11.00 from JTF for 4L, Since about 6L are needed with the deeper pan, two 4L containers of oil were purchased at £22
The aluminium oil pan has cooling fins and this helps to stop the oil from overheating. If oil overheats, it becoming thinner (less viscous).
Cooling fins help to maintain the correct viscosity. A thick finned aluminium oil pan is also very resistant to knocks from uneven ground.
Spal 30102049 curved blade pull high performance fan and gasket. Price £125 ($180)
Spal Automotive USA high performance 16" fan £100. Spal fans are original equipment in Caterham and Morgan cars. They
are used by the Pro Drive Racing Team and the M-Sport World Rally Cross Racing Team. Also required was a Spal electric fan
cowl hard rubber at £25. The existing fan in the truck was from Summit Racing and the temperature sensor was in the bottom
hose. This new fan is much thinner, had more blades and was more efficient. It was positioned lower than the existing fan.
The temperature sensor was fitted into the engine. The position of the alternator was above the old manifold and not in the air
flow of the old fan. This was identified as a problem. The alternator was hot due to the heat from the manifold and insufficient
cooling. A special bracket was sourced from RH Jones Racing Products to move the alternator in front of the engine and into
the air flow of the fan. This special aluminium bracket had an adjuster which allowed the tightness of the belt to be adjusted with
a screw thread. Much better than pulling the alternator by hand or with a lever while tightening the bolt. This bracket was an
additional £40 ($60) It was decided to replace the top hose with a better performance hose at £35.00 Add £75 ($110)
Total cost of upgrade parts £1300.00 (about $2000.00)
Road tests.
Road tests finally took place in May 2016. The rather long delay was due to the whole truck being painted to a high standard
first and then a few more small engine upgrades.
The engine upgrades were - The stock water pump was replaced with a polished aluminium, dual heater pipes, finned water pump.
Wires running near the engine were put in flexible stainless steel conduit.
The road test was complicated by the inclusion of the Stage 2 high performance automatic transmission which resulted in gear
ratios with high acceleration but not ideally practical in the streets. Basically the gears change at higher speeds than stock
(higher RPM). This will be corrected by a new governor (with larger weights.) Apart from that there is really a large increase
in performance. The truck has a lot of get up and go. Going up hills is effortless. Kicking down produces immediate
acceleration. Power delivery is smooth and increased performance seems to be there at all speeds. The mods have worked
extremely well and have significantly increased the horsepower.
An improved cooling package is planned for 2018.
