Straight -cut or Cross-cut Cam Gears

17th may 2008

The debate between strait-cut gears and regular cross-cut gears has been ongoing for some years and is something that many engine builders will come up against and will have to make and educated guess based on the information that is available to them.

Certainly the pros of the straight cut system are the increase in performance that the straight cut gears low friction give. The Cross cut gears however seem to have a much stronger build quality usually made from aircraft gauge billet Aluminium or Magnesium where as the straight cut gears are noticeably thinner and made from steel or use a steel gear and alloy drive gear. I originally elected for the Cross-cut gear system as I was also aware that the straight cuts system gave the engine an odd wine as the gears spun together.

The two featured camshafts are on the straight cut gear above left an Engle FK8 and on the crosscut to the lower right a Bugpack high lift cam.

The use of this lightweight and narrowed straight cut cam and crank gear set will virtually eliminate all cam bearing thrust wear created by high lift cams and high pressure springs. Straight cut gears are also available in an adjustable type witch allows fine tuning of the valve timing from the cam. A typical engine built with a straight cut cam can be heard here: http://www.youtube.com/watch?v=SynhO3LoJsA. The wine is very noticble and can be mistaken as the sound of a supercharger.

The Cross-cut gear type apparently wears better and is now also available in adjustable models and also some with steel and alloy mixed gearing sets.

Personally I am going to fit the Straight cut gears and see how they fair in my new engine. I will write in another blog on how to set up the cam with the correct the adjustments when I get to the pre-build make up.

MOT the real deal

15th May 2007

Some serious time has passed since I last wrote on this blog leaving me feeling a little busy and feed up with the garage that had mot'ed my buggy way back in March. My buggy had been sitting in the garage for most of this time waiting for me to get motivated again and to have it retested. I had contacted DVLA regarding the garage in Ford garage in Battle that had mot'ed the Buggy in March but I had no response regarding my claim that the MOT had been done unfairly and my request for the test fee to be returned. I decided enough was enough and took the buggy in for a retest at Leaders Engineering in Hastings, I had been told that they had some experience in Kit cars and tried to make an appointment to have the buggy mot'ed. The weather was not on my side and I could not seem to get a day that was not raining to go. Eventually I plumped for Friday and took the vehicle into Hastings to have it Re-tested. The MOT started off well and the engineer was very thorough going all over the vehicle. Watching this I was worried as the Ford Garage in Battle had stated that the front Calliper was leaking amongst other faults. To my amazement the car went through the MOT with a totally clean bill of help.

Now seeing the car had been in the garage since its last MOT and nothing had been done to it I can not understand why the Ford Garage was stating there was a fault with the calliper that seemingly repaired itself. I will leave this for my readers to ponder on as I have already made up my mind.

MOT SAGA retest

8th April 2009
My MOT re-test had been rebooked for 1:30pm on 7th April 009. The buggy seemed to be a lot better on the road and I had had a friend have a look at the vehicle with me on the weekend so had been fairly confident. I watched as the Young MOT test man tested the brakes and all passed with flying colours I was fairly confident that I would get a pass. The MOT man seemed to take a long time to come out and I began to have doubts that he was going to pass the vehicle. He returned to my amazement with a failure for seven more items , some which had not been found on the original test. I took the paperwork from him not wanting an argument and went home. Later that afternoon I rang the Ford agent in Battle where the MOT had took place and asked him why and if they had retested the whole car again. He said that they had and that if I was unhappy with the test result there was a number on the back of the test sheet to ring and make a complaint. Now I had always thought that an MOT test only tested the things they found wrong the first time as the 10 days that where given to you was so that you had a fair chance of passing. I decided that I was going to ring DVLA and clarify the situation as it seems pretty irregular and to be honest I had already had the feeling that the test person did not want to pass that they would send out an inspector as the MOT failures looked very odd.

Mean while I still did not have an MOT. I decided that I wanted to change the rear brake line fixings as I was not really happy with then and wanted to design a better bracket. I had tried to modify the existing brackets but was not happy with the result . I cut the brackets from 5mm stainless steel and the holes where drilled as 11mm and 14mm. The bracket was 75mm x 24mm on the longest side and 24mm x35mm on the other. I cut small slots into the largest hole to act as a locater to stop the hose from spinning ithe car. I tried to make it not give any contact to any of the other pipework on the rear of the car.

I would have to find another garage to MOT the buggy as I would not be using this garage again it is very sad that I had to make my mind up with that as previously I had had a good releationship with the gentleman who owned the business. I hope that VOSA are able to put his business back on track and that he will able to say that his business is better for this not worse as I hate to see a business fail in these economic conditions.

MOT failures,brakes and a stiff test station

5th April 2009
Finally March has passed and the problems of the month seem to be disappointing. It has been a harrowing month of family problems some still not resolved hopefully favourably by the end of this week.

My buggy had also had an MOT failure. I had chosen the closest testing station Stiles Garage in Battle East Sussex which is a Ford dealer. It was also the Friday before Volksfest and I really wanted to have the buggy on the road.

The MOT test man pointed out 24 items that he felt in his opinion needed to be changed before he would pass an MOT on the car. To be honest some of these where very good finds the others seemed to be a little pedantic and ranged from bolts not protruding far enough from nyloc nuts to the wind screen wipers not laying flat on the body work, to the accelerator pedal being to close to the brake. I had a bigfoot accelerator pedal on the accelerator I think he didn't like it.

However the main failure was because of the rear disks. The rear disks did not seem to operate other than via the hand brake cable. Obviously this was very good to find and was worth the MOT test price alone.

He also did not like the noise that the exhaust was making stating it was obviously to loud lol. Funny I thought that was normal on a buggy. I had used a straight through exhaust on the temporary engine and realised I would have to create a baffle that would stop some of the noise escaping and offending people. A Friend suggested using a tail pipe from a beetle exhaust this was a pretty good idea as it had a baffle already built into it. The only problem was that the tail pipe and the exhaust where totally different sizes. Initially I tried securing the tail pipe into the exhaust with three opposing screws . This only slightly improved the noise level and it was obvious that the end around the baffle/tailpipe needed sealing. I thought I could wrap the tailpipe in exhaust wrap but unfortunately could not find enough material to wrap it up to the required size. Eventually a motor factor came up with a coupler that was a reduction pipe. Although this was not the correct size I worked out that it was the same size difference on both sides of the adapter. I sliced the adapter up its length and removed enough material to allow the pipe to fit. I remembered to use PI to work out the circumferences of the size i needed and the size of the existing pipe so that the difference between the two was what I removed. The adapter was then fastened on with exhaust clamps.

The end of March turned into a saga of fault finding on the buggy with the the hydraulic system being bleed and bleed and bleed with little success. I had read that the nipple should be facing up and not down so changed the callipers over from side to side. This also had the advantage of getting the handbrake cables further of the ground giving better road Clarence.

Unfortunately this did not resolve the problem I bought a Gunson pressure one man bleeding system that fitted onto the hydraulic reservoir. It pressurized the system 7up so that you could just bleed the fluid and the calliper nipple. This eventually gave some success however the rear brakes where now braking the pedal was traveling and hitting the bulk head which would be seen as another MOT failure.

I had spent the rest of March trying to think how to resolve this problem I placed threads on http://www.thesamba.com and on http://www.volkzone.co.uk . Eventually a member of the samba suggested that as my master cylinder was lower than my calipers I would need a residual pressure valve to keep the pressure within the caliper section up to 2lb. Now I was not aware by posting this onto volkzone that this would open a tin of worms. Several members of VZI said that this would not solve my problems other members suggested that my brake push rod length was the wrong length and might need adjusting. I ordered the residual 2lb wilwood valves and would have to try them when they turned up two days later. These promised to eliminate excessive pedal travel. I also managed to remember that these items needed a special adapter to connect them to the 10mm copper pipework as they where a Jic thread and ordered the adapters at the same time. I would also need to make up new hydraulic lines to connect to the valves. The lines would need to be 500mm long with two concave 10mm male connectors. In the middle 170mm from one end I would need to have convex female adapters. Bearing in mind the valve was 70mm long this would give me two lines one 170mm and one 260mm per side.

Later today i made another trip down to the garage and spent some time looking over the whole hydraulic system with a good friend and buggy enthusiast John. I had decided before coming that I wanted to check the brake pedal position something which was often overlooked when changing the master cylinder or removing and refitting the pedal set.The pedal was supposed to travel up to 3mm before hitting the piston in the master cylinder. Mine was over 15mm and once it was reset the pedal started to react better if not totally correct. A drip was noticed on one of the flexi-joints on the rear A-arm tightening this made the pedal movement a little better. I think the real change will be made only by the residual valves that i currently have on order and my hydraulic lines have been made up. My MOT retest was looming and I was not going to have time to fit the residual valves before the retest. The only question was would it pass or fail?

Super Flow Heads

12th March 2009.

I have been looking for some new 94mm heads for my new engine build for some time. Eventually after a long time some had turned up on eBay and they where wonderful 94mm Superflow heads tweaked and generally had everything known to an engineer done to them. Having blown my budget on a crankshaft and h-Beams I was not in a position to buy them and tried to broker a deal with him paying him payments he never accepted my offer and sold them at a lower price than I had offered him. I was gutted.

VZI to the rescue. Feeling at a loss for what to do as this had been the next vital part i needed a member of Vzi had noticed my thread and luckily had another set stored in his garage. After some discussion It was agreed that I could secure the purchase with £100.00 and pay the rest on collection. He sent me some pictures through vzi I could not believe my luck.

I havent mannaged to speak to the seller yet as I had lost my internet connection and his number I hope he will see this an give me a message.

Mad March affairs

9th March 2009
The start of this month has been utter madness my buggy has been off road for some months and this has only been reiterated in my head by DVLA sending out a tax reminder. This month is going to be utter madness. With my new engine still in dry dock on the living room table in boxes. The past winter months have bought an appathy in my head about the time I have spent in search of this new engine. My original estimates of the cost of this rebuild have been re worked out time and time again the high dollar price has caused prices to sore. With this said I have to look harder for parts and have been in search of some super flow heads. The first set I found I lost due to a ebay failure .Luckily I was approached by another Vzi member who offered me a similar deal. I am hoping this will be more fruitful. I have also decided to sell some of my old engine components and I hope they will be well loved as they have been on my buggy.

In the meantime i have had my case bead blasted and it has returned to me in a wonderful condition. I still need to have some engineering work done on the case. I hope the engineering work will be successful and will happen after I have aquired the heads.

In the meantime MOT and taxation looms at the end of March and I have a couple of issues outstanding before the buggy will be ready for an MOT. The first being the holes I had cut for the Drag bar that would need to be fibreglassed.

I decieded to use polymer fibreglass from a modelk shop instead of the usual kits that is sold in the garages in my area. This is a higher quality product and gives a longer cure time so it can be worked to provide a better fit. I made peices of card board to fit the holes and coaded the surface of the card with some household wax polish the hard block type. The cardboard was then mated with the body work so as to provide a framework for the fibreglass to sit against. I was careful to try and match the battery box indent that was on the other side of the car . The result is shown in the photograph. It hasnt been cleaned up as get and the underside has also not been fibre glassed. I am wonering whether the hole body needs to come of to do this and If it does I want to then seal the inside of the body work with a stiple effect. In the meantime its been sealed and should now go through an MOT.