Tag Archives: Needle

Fire in the Hole

Posted on by

We had planned to run the engine on the starting stand with the gearbox fitted, but thought better of it. First, it would mean that we would have to figure out a way to keep the driveshaft fork in the nose of the gearbox so we would not leak oil out the end. However, more importantly, we wanted to inspect the clutch and the ring gear. So we modified the starting stand to include a mount for the engine rear backplate. 

We then hooked up the choke cable to the carb and we installed a lawn mower throttle cable and slide controller on the control panel and also hooked it up to the carb. These are shown in the video with the link below.

Water was then added to the radiator, Valvoline Racing Oil 20W-50 was added to the engine and some automatic transmission fluid was added to the HIF-44 damper. We then disconnected the coil and spun the engine with the starter until we had oil pressure. After checking ignition timing one more time, and testing for spark at the plugs. It was time to fire it up. It ran pretty well but seemed a bit rich at idle.

After a pause to work on other projects and to wait for parts, we came back to the engine to try to improve the engine’s tuning and to check on the clutch and ring gear.

The clutch had worked just fine but we decided to go ahead and replace the disc and pressure plate since the engine was out of the car. While we were at it, we also made plans to take the flywheel to a machine shop and have the face resurfaced and have the flywheel and clutch pressure plate, or cover, dynamically balanced. That is when things got interesting!

We took the flywheel to Southwest Hydraulics in Venice, Fl for resurfacing, but we got a call from them indicating that the flywheel was “coming apart.” As it turned out the flywheel had been lightened a bt too much and there was very little material between the flywheel lip and the ring gear. See below.

Flywheel delamination

This is going into the trash!

Since they no longer make steel flywheels for the 1275 (aluminum lightened flywheels are available) we searched eBay and located one. It had not been lightened at all which we preferred, but it was not without its problems. One of the clutch cover bolts had been broken off in the flywheel. Fortunately, our friend Randy Forbes came to our aid. Using his milling machine, he first flattened the top of the bolt shaft and then with his drill press using a LH drill bit he was able to remove the broken bolt with no adverse effect. Thank you Randy!

We then took the flywheel back to Southwest Hydraulics for the resurfacing and we also had them replace the ring gear with a new one sourced from A.H. Spares

Flywheel resurfaced

Then it was off to “VAMI” – Venice Auto Marine machine shop where we had the flywheel balanced. Unfortunately, we could not balance the clutch pressure plate with the flywheel because the center hole in the pressure plate was too small to fit on their machine. This should not be a problem as the pressure plate comes balanced by Borg and Beck. The new disc was sourced from Rivergate.

We then reinstalled the flywheel, clutch disc and clutch pressure plate. The flywheel bolts were new and torqued to 4o ft. lbs. A locking tab washer was installed and all the tangs were bent over. The clutch bolts were torqued to 19 ft. lbs.

In the meantime, we replaced the metering needle that came with the carb with a “BDL” needle to get some additional fuel at start up without having to rely so much on the choke. Randy Forbes again came to our aid with the installation of our oxygen sensor.

Oxygen Sensor Bung Installed

Randy doing his thing!

He installed a bung into our new exhaust pipe for the  oxygen sensor so that we could use our newly purchased Innovate Motorsports AFR gauge. This is very helpful in adjusting the fuel mixture at the carb.

Innovate Motorsports AFR Gauge

Before starting the engine a second time we also decided to replace the original-type Lucas starter with the gear reduction starter we had. 

We then started the engine a second time and we were pleased with the changes that had been made. The engine seems to be running well with a static advance of 12 degrees and a full advance of 31 degrees at 3,800 rpm. All of our changes and the first and second running of the engine are included in the Bugeye Restoration Video Episode Sixty. 

https://vimeo.com/953122217/a96f4deab1?share=copy

Episode Sixty includes the following content:

0:35 – Gearbox removal

2:30 – Throttle control

3:35 – Choke cable

4:40 – Engine fluids

6:35 – Priming the oil pump

7:35 – Checking for oil pressure

8:10 – Ignition timing

8:32 – TDC Compression stroke

9:00 – Checking for spark

10:35 – Engine starts!

11:30 – Ignition timing again

12:20 – Marking the distributor setting

12:30 – Gear reduction starter reinstalled

13:10 – Innovate Motorsports AFR gauge

14:08 – Engine running again

14:45 – Engine storage until it goes in the car

The exhaust was then removed along with the intake manifold, the HIF carb, and the exhaust header. This was done because we are sending the exhaust header to Jet-Hot for a ceramic coating. We have now covered the engine and pushed her to the side. The good news which is really too good to believe, and surely will not last, is that we have no oil leaks!

Wow, we started this engine work back in September of 2023. Considerable time has passed but we were continually diverted to work on other parts of the restoration. Other than coating the exhaust header we believe the engine is now complete. Hopefully, by Christmas she will be reunited with the car and it will be as easy as installing the engine and gearbox and taking the car for an initial run!

 

 

Carburetor Swap to HIF 44

Posted on by

The Bugeye originally had 1 1/4″ twin SU carburetors. We upgraded to twin 1 1/2″ HS2 carbs shortly after purchasing the car. With the current restoration we are going to try a single 1 3/4″ HIF44 carb. We hope to attain equal performance without the need to balance twin carbs. The single HIF carb was routinely used on Minis with essentially the same engine. The HIF 44 is SU’s most modern carb of the period. The float bowl is integrated into the bottom of the carb body rather than a separate float bowl as with the HS2s. 

Using the HIF carb requires the use of an appropriate heat shield with integrated securing points for the throttle and choke cables. I ordered this one https://www.ebay.com/itm/163969687994  not only is it polished stainless, it also provides an angled extension under the bottom of the carb (where the float bowl is located) to provide a little extra heat protection. This is a very nice piece.

Modified stainless HIF 44 Heat Shield

 A custom intake manifold is also required on the Bugeye. Sourced from Maniflow in the UK. This manifold lowers the carb so that it will not foul against the bonnet.

Maniflow 1 3/4″ Intake Manifold Jet-Hot Coated

After purchasing the HIF44 we sent it to A.C. Dodd in the UK to have him modify it slightly. The biggest change was converting the unit from manifold vacuum to ported vacuum. Bugeye Restoration Video Episode Fifty-nine reviews the features of the HIF 44 and explains the modifications made to it by A.C. Dodd to prepare it for use in the Bugeye.

https://vimeo.com/924772088/d53a91b278?share=copy

Episode Fifty-nine includes the following content:

0:05 – HIF 44 carb documentation

0:45 – Applications of the HIF 44 carb in other cars

1:37 – HIF 44 carb needle

2:20 – Manifold and Ported vacuum

2:26 – HIF 44 Carb heat shield

2:32 – Maniflow intake manifold

2:50 – Choke cable retaining clip

3:23 – A.C. Dodd HIF 44 modifications

5:33 – HIF 44 Hose fitting legend

5:39 – HIF 44 Throttle and choke cable connections 

Setting up the HIF 44 for initial running is really quite simple. (more info to follow shortly!)

HIF 44 Carburetor (RH Side)

HIF 44 Carburetor (LH side)

Setting the fuel mixture is the first step. This is accomplished by turning the fuel mixture screw shown in the image above. The image below shows the proper level of the jet:

HIF 44 Proper Jet Height for Start-up

Turning the adjustment screw to the left will lean out the mixture by raising the jet thereby letting less fuel enter the manifold. Turning it to the right will enrich the mixture. This screw should only be adjusted to effect a change in the idle. It should not be adjusted  to improve the drivability of the car at speed.

The fast idle, or choke, is set by adjusting the fast idle screw against the cam. The images below show the proper setting. The fast idea screw is turned down until it just touches the throttle lever. Once in that position it can be turned down one full turn. A feeler gauge with .018 blades is then inserted between the fast idle screw and the throttle lever. The choke lever is then rotated to line up with the center of the throttle adjusting screw. This is achieved by turning the adjusting screw until it just touches the arrow.

HIF 44 Adjusting the Choke

A small spring clip is used to secure the choke cable end fitting to the heat shield choke bracket. It is a friction fit and is just pressed down over the end of the cable ferrule.

HIF 44 Choke Cable Clip

A two piece cable stop is used to secure the choke cable to the choke lever:

HIF 44 Choke Cable Stop

 We also decided to improve air flow into the carb by installing an aluminum stub stack sourced from M.E.D. Engineering in the UK.

MED Stub Stack

Their site describes the billet stub stack this way:

The MED aluminum stub stacks have been extensively tested on our 110 Superflow flow bench to optimise the elliptical radius on the stub stack. The result is improved air flow to the carburettor/throttle body and a proven increase in performance – on a wide range of different engines and rolling roads.

The stub stack is temporarily mounted in this photo. Eventually the K&N air filter back plate will be installed first with the stub stack mounted inside the filter assembly.

Stub stack temporary installation

Much of the tuning of the HIF 44 carb is accomplished through needle adjustment, spring choice and variations in damper oil weight. Our carb came with a BFY spring loaded needle. Upon initial running (but before we have connected an AFR gauge) the engine seemed to run well at higher rpm but lugged a bit at idle and required the use of the choke for longer than expected. We wondered if the BFY needle was the cause of insufficient fueling at idle, so we decided to try a BDL needle. 

The .100″ jet needles (the middle needle below) are measured in 16 increments:

Needle Metering Increments

The following chart depicts the difference between the BFY Needle and the BDL Needle. As can be seen, the needles are very similar. The only differences are in positions 2,3,4 and 5. This should leave us with a slightly richer condition at idle and maintain the same fuel condition in the higher rpm range. Hopefully we will not need as much choke this time. Additional running will tell us if we have improved our running at idle or not.

BFY and BDL Needle Comparison

Finally, we are using a K&N Cone-type air filter for the carburetor. We sourced this one from Moss Motors:

K&N Air Filter

K&N Filter Packaging