Engine Breather

Managed to get out in the car over the Christmas break, I was keen to see how my PCV valve worked - I was looking to see how much crankcase depression I was getting in various engine conditions - my measurement method was a digital manometer hooked up to my dipstick tube. Didn't get very far before I realised my first simple in-line valve was giving me too much depression, it wasn't able to control the pressure. The downside of this is that in extreme overrun I could potentially suck the oil into the intakes.

Time for Plan B, I had picked up a diaphragm type PCV valve, only problem was finding somewhere to fit it, no room on top of the intake manifolds.

After some pondering, decided to use my redundant distributor mounting, This needed a bit of machining to make it suitable, I also added a fixing point to hold the valve in place.

Not sure where I originally picked up this valve.

The valve pushes into the modified distributor housing and is held in with a small cap head bolt.

Fits quite neatly on the side of the block

Plumbed into the intakes via some 1/2" tubing pressed into the end of the manifolds.

Checked everything was fitted ok and started the engine, my pressure gauge was showing a 15 mbar depression at idle. Took it out for a drive, subjecting it to various operating conditions, the valve seemed to pretty much maintain a constant 15 mbar depression +/- 10 mbar. The original engine breather is now the fresh air into the engine crankcase and is fitted with a small restrictor to create the depression. With no restrictor it would be like having an air leak post throttle in the intake system.

Didn't get much else done, really need to trial fit my front upper wishbones - once I know they fit of I can get on and make another set with the thicker wall tubing and then ream the internal bores to the correct size.

Trunnionless Link and Friends

Well, recently sold an injection kit so this has allowed me to spend a bit more on my car, collected the parts this week. Caterham style vertical links that will fit into spherical bearings in yet to be fabricated lower arms.


Alloy hubs with larger stub axle and improved bearings.

New 10" vented discs

And a very nice pair of AP Racing calipers, couldn't believe how light these calipers are, a friend has promised to get me a set of decent pads, they should arrive over Christmas.

No immediate plans to fit them yet, need to get the top and bottom arms fabricated first, also got another couple of engine related bits to finish off over Christmas so I've got to keep it mobile.

Top Arm Update

First pair of top arms have been welded, not bad, they have twisted very slightly and sprung in about 20 thou. The tube for the top ball joint has also distorted slightly making the adjusters a tight fit. I expected to have to make a couple of tweaks to perfect the design, this first set will be used to check for clearance issues with the front upright and to make sure I can get enough camber adjustment with no lower shims fitted.

To address some of the issues, the next arms will be made using the jig removed from its back plate so that a number of tack welds can be put in place on both sides to prevent distortion (springing). I'm also going to use slightly thicker tubing and then ream to the correct size.

Front End Modifications

I've decide a while ago that I was going to convert the front uprights to Canley Classics / Caterham front uprights, primarily for the stronger stub axle as well as doing away with the lower trunnion. I had a stub shaft fail on the motorway a couple of years ago, initially thought it was a wheel bearing until I stripped it all down and found the shaft had broken at the start of the threads.

Anyway, that started me thinking about the front end, as I use quite a large wheel and tyre, I cant lower the front end too much as I end up with contact between the tyre and arch, while looking at various kit car set ups I have decided to fabricate my own adjustable top arms and do away with the shims on the lower arms. Hopefully this will pull the top of the wheel in a little more and give me some more tyre / arch clearance. If I need more I will fabricate lower arms that are slightly shorter and adjust the tops to compensate.

I have borrowed a home made tube notcher to get the right angle and profile

This made light work of cutting the tubes

As a couple of friends have shown interest I decide to knock up a jig to aid with the fabrication.

Just need to find a good local tig welder

Knocked up a couple of adjusters that will allow me to adjust the camber without having to remove the top ball joint.

I will hopefully get these welded together in the next week and then I can make sure they fit ok. I have used 25mm x 2mm wall thickness for the bush holders, 20mm x 2mm for the rest, all seamless tubing.

Got some drawings ready for the bottom arm, just need to see what effect the top one has before I make anymore jigs. The lower arm will be made to hold a spherical bearing.

Oil Leaks

Following the 10CR I developed several oil leaks, front seal, head gasket (push rod side) and rocker cover, all fairly standard but the strange thing was my engine had always been fairly leak free.

In a flash of inspiration sat on the front wheel staring at the engine drinking a cuppa, It suddenly dawned on me that I had modified my air intake system and that maybe it was having more of an effect than I had realised.

I connected a pressure gauge up to the dipstick tube and started the engine. Sure enough a small vacuum as expected as my breather system is plumed into my intake plenum upstream of the throttle bodies.

Took it out for a drive around town, still the same, slight depression on the engine. Found a nice quite road and increased the speed, at around 50 mph light throttle my gauge started to show a positive pressure in the crankcase, not good.

I pulled over and connected the pressure gauge directly to the intake plenum upstream of the throttle bodies in place of the engine breather and went for another drive, what I found was quite interesting, when travelling over 50 mph on light to half throttle I was registering a positive pressure in the intake system, good for performance bad for my breather system. Bearing in mind that on the 10CR (while on the autobahn), we could easily sit at 110+ mph on very light throttle, who knows how much pressure my crankcase was seeing, no wonder it developed oil leaks.

To sort the cause of the leaks I have decide to connect my breather system to the engine side of the throttle bodies and used a PCV valve to make sure it doesn't suck my oil out. I have cleaned up the engine bay and now await suitable weather to take it out for a run.

Mazda MX5 Seats

This post is in response to a recent topic on the Club Triumph Forum, It does not give all the details but highlights the main modifications.

One of the problems I had when fitting MX5 seats into my car was getting them to sit low enough and as far rearward as possible to give me enough room. At 6'1" I need as much legroom as possible.

One of the problem area's is the rear floor pan where it flares out at the rear of the tunnel. If you mount the seats on top of this you end up with very little headroom.



To get around this problem, I fully stripped the seats so that I was left with just the seat pan and then by trial fitting, removed enough material from the pan to clear the tunnel area, make sure you leave the seat hinge area untouched. Make sure you take into account the height of the runners (if you intend fitting them). I then welded in some 20mm angle iron to give the seat pan some strength in the hinge area. I have highlighted the modified area in the following picture.




I used some aftermarket seat runners as the seats I bought didn't have any, the inner runner needs to be modified to match the seat pan. On my setup I used the original MX5 seat mounting points on the outer runner and the front fixing on the inner runner, I welded in a nut for the rear fixing on the inner runner.

To mount the seat in the car, I made up 4 lugs that allowed me to use the original mounting points in the floor, you could probably gain another 15 mm headroom if you were to mount directly to the floor, you obviously then have no adjustment.

I used Securon seat belts with short steel stalks and bolted these directly to the seat in place of the MX5 seat belt stalk. There are slight differences between the driver and passenger seat but you basically make the same modifications.

The seats are very easy to strip apart, you remove the complete backrest as one assembly leaving it fully trimmed, then remove the cover and foam from the base, its all held in place with small wire clips that can be opened up, I'm sure you can buy these new along with the correct fitting tools but I just re-used the originals.

Car toons...........

A friend of mine did a "quick sketch" of my car, I think it looks quite good.

Let There Be Light

Not really happy with the lighting following the 10 CR, never really noticed any issues in the past, then again never really had to drive it all night before. The biggest issue was the amount of glare / refection created when using main beam.

After looking at a TR6 recently at KD Triumph that had a HID kit fitted I was pretty impressed with the installation, I have HID's Xenon's on my everyday car so I'm well aware of the improvement they offer.

A quick search around the Internet and I came across a Bosch HID kit for a fairly reasonable price.


Fairly straight forward to fit, you get all the necessary brackets and fixings. There is a unit that needs to be fitted behind each lamp, I fixed these to some existing fittings on the wheel arch. There is also a control module that needs to be fitted on one side only, this needs an additional 12V feed. It also has a fly lead which plugs into the existing bulb connector. The bulbs basically fit the same as standard H4's, they just connect up to their own harness.



Difficult to show in a photograph but the light is much whiter and brighter as expected, they make the sidelights seem really yellow. I'll have to plan a night drive and see how they perform.

Club Triumph 10 CR

What a trip................




I was a little apprehensive about doing this trip, mainly because my car had only covered about 2500 miles since its rebuild and I was about to double it. I needn't have worried, the car ran very well. I had spent the last couple of weeks checking, greasing etc etc and did not really expect to have any issues but you never really know in a car that is over 30 years old.

We averaged 27/28 mpg over the 2500 miles, 35 mpg was the best and 21 mpg the worst while tackling the mountain routes around Stelvio.

At one point we did suffer steering column shake and vibration but this was quickly diagnosed when the radio fell out and I realised that the H frame bolts had come undone.

We had another issue with a change in exhaust note and strange vibration which did get me a little worried, once we pulled into the service station this changed to a rattle from under the car, after a quick inspection, I found that the exhaust hanger U bolt had come loose, this was tightened and everything was fine again.

Apart from a little tyre to bodywork contact, that's about it.

I did learn quite alot about the car, this has given me a couple of things to investigate.

I had fitted 100 Watt bulbs for the event, while these were superb in complete darkness, with no reflective road markings or signs, If you tried to use main beam on anything reflective you were immediately blinded. My plan to overcome this is to fit some HID lights, they'll be the topic of another post.

My car handled exceptionally well, even in very wet conditions, what it didn't like was crossing road expansion joints in mid corner at high speeds, this became quite uncomfortable when going through series of tunnels during the trip. Not sure what I'm going to do about this as I cant slow down....... I think it looked more dramatic from the cars that were following as the car moved around. I don't plan on changing the wheel and tyre set up so I think I will have a mess around with the damping.

Developed a couple of oil leaks, one from the head gasket and one from the front crank seal, all pretty much standard stuff.

Might have a play around with diff ratios as the car does lack a little pull away performance, I think this is due to having 215/40 R16 tyres. I'm currently running with a 3.89 diff, I plan to swap this in the next few weeks to a 4.11 and see how that goes. I will happily trade some top speed for more acceleration.

I guess the only other thing to mention is that I had a pretty good co-driver, my brother Andy, he was quite happy to sit back and let me drive, when he did drive, he respected the fact that this was my car. We also met some great people during the event, only problem being that I didn't really remember any names but I'm sure we will meet up on future events.

The following link should take you to a short video of the GT6 at the Nurburgring http://uk.youtube.com/watch?v=_Ut2zz2841w

Thanks to Ellis and all at Club Triumph who organised the event.

Six Pack

I Wish..............

Couldn't find anybody locally that had a new distributor cap in stock on Saturday morning, so I decided to pull my plans forward and fit a wasted spark ignition system using a six pack coil. Originally I was going to do this after the 10CR but I got carried away.

Managed to pick up a couple of second hand coil packs and leads on eBay, I used a Mondeo V6 coil and cut the leads to suit.

Dead easy to wire in and set up, just a couple of extra wires to the ECU and then reconfigure the software to run a wasted spark system.

The most time consuming part was making a new bracket for the coil and blanking off the distributor hole.

I basically hacksawed my old distributor mounting casting, this was loctited in place leaving a small clearance to the oil pump drive shaft. I then made a plate, sealed it with RTV and bolted it in place.

Following a test drive, this seems to have cured my 6000 Rpm ignition issue, I now seem to have another issue up around 6800 - 6900 Rpm. Not sure if I need to fit stronger valve springs or I'm having issues with the crank trigger signal.

My trigger wheel is mounted on the back of my crank damper, not sure if the damper is resonating and causing an issue, I think this is unlikely as I'm able to log all the engine signals and all appear to seem OK - I need to investigate further............

My valve springs were bought from Chris Witor, I'll give him a call in the morning a see what he thinks.

Rolling Road

Spent the last month getting my car ready for the 10 CR, one of the main jobs has been to switch from my existing ECU to an Emerald K3. After making a new harness, trigger sensor bracket etc etc, finally got it up and running two weeks ago.

Spent the last couple of weeks mapping but couldn't get rid of an issue around 6000 Rpm, decided to get it booked in for a rolling road session. It was always the plan to optimise it on a rolling road, my only concern being that if the engine let go, I would be out of the 10 CR.

I'm glad to say all went well, the guys at Thor Racing managed to squeeze a bit more power and torque out of it. As with all figures these will vary from day to day, rolling road to rolling road however they do give an indication.

107 lb/ft @ 5580 Rpm

123 Bhp @ 6194 Rpm

Didn't manage to fix the 6000 Rpm issue but did a bit of investigation, basically its looking like a distributor cap issue, off to buy a new one in the morning.

A bit unfortunate as it was looking like there was a bit more power to come, I'm planning on setting the limiter at 7200 Rpm.

Aerodynamics

Numerous people have told me that the reasons why GT6's get so hot under bonnet is down to poor air flow and that what I need is bonnet vents, while this may be true I don't want to hack holes is my bonnet without understanding what is going on.

I have fell into the trap of believing the more air I get into the engine bay the better things will be, I am now starting to doubt this. It originally suited me to have maximum clearance at the front of my bonnet as it allowed me to get my radiator in without fouling the bonnet. The down side of this is that at high speed the bonnet can be seen to lift and starts to move around - this suggests to me that I have a high pressure area under bonnet which in turn leads to poor airflow through the engine bay. After reading several articles I have decided to try and understand what is going on aerodynamically. I plan to take numerous pressure measurements around the front of the vehicle / engine bay / under chassis in a bid to come up with some potential changes.


My aim is to have a high pressure in front of radiator, slightly lower in engine bay area and identify even lower pressure areas under the vehicle so that I can use these areas to draw the air from the engine bay, I will also try and determine if bonnet vents will actually improve the situation.


Over the weekend I have moved my radiator back and pulled the bonnet down at the front as far as adjustment would allow, after a quick run this morning this has stopped the bonnet lifting at speed with no adverse effects to the cooling performance, if anything it actually ran a little cooler than normal.


Next thing is to start taking pressure measurements, I have also made an undertray that I intend to try.

If you have any idea's, comments or theories please let me know.........

Cold Air Intake

One of the down sides of fitting a larger radiator is that it restrict where you can get a good source of cold air for the intake. I had made do with a KN on the end of my plenum, only problem is that when idling and driving slowly the air intake temperatures climb quite rapidly, the air temperature sensor fitted in the plenum lets the ECU know whats going on which in turn backs off the ignition timing to prevent detonation, this can have a major effect on performance.

Following numerous cardboard templates I have come up with something that seems to work quite well, I have fabricated an air box with filter that sits below the radiator.



This is fed cold air via a scoop that fits in front of the radiator



The air exits the air box via a 60mm outlet fitted to the rear and connected to the plenum via trunking.

I don't expect a performance increase from any forced air effect but it should help overcome some of the restrictions of the filter and trunking. Having driven the car with the old and new intakes there is no noticeable difference in performance when travelling at speed.

Idle and low speed intake temperature's have drastically reduced, the next job is to move the air intake sensor into the air box as it does pick up a fair bit of heat soak in its current position - Its currently fitted on the underside of the plenum.

Cooling Mods

Although the cooling system worked ok prior to my rebuild, I have tried to improve the set up to try and ensure I don't end up with trapped air in the system. I have basically added pipework from the header tank to the downstream side of the EWP. Originally this pipe went back into the head.

I have also moved the bleed from the top of the radiator to the thermostat housing.

This hose is fitted with a 4mm restrictor, the idea being that as the pump draws coolant, from the radiator and header tank, it creates a lower pressure in the header tank, this in turn should draw any air in the thermostat housing back into the header tank.

Made up a couple of pipes that fix to the rocker cover studs to keep it all looking tidy. Unfortunately not very easy to see in this picture.

The heater feed pipe (originally the heater return pipe into the back of the original water pump) is up stream of the EWP, with the heater valve closed all coolant flow is directed through the engine, with the valve open, some coolant flow will go through the heater and back to the header tank. All seems to work ok, just experimenting with water levels and pressure caps. Started with a 20 Psi cap but have now got this down to 13 Psi.

Exhaust Manifold Clearance

Engine is now back in, re-wrapped the exhaust manifold and trial fitted it, with so much material removed from the block and the head - close to 1/4" - I had to create some clearance around the turret. This has always been close so out came the grinder - I could have raised the engine but its pretty tight at the top end between injectors and the bonnet.

Also had to put a bit of a flat on No. 1 primary so that it didn't foul the mounting boss on the block.

Spindles and butterfly's fitted, need to get hold of a couple of cap head bolts for the awkward manifold fixings

Should hopefully be running this week if I get some time down the garage.........

Engine Complete

My replacement cam arrived last week so I was able to finish off the rebuild on Saturday afternoon. I opted for a Newman PH3 300 degree duration cam, this had to be timed to achieve full inlet valve lift at 110 degrees after TDC. I initially set this up without the head fitted then rechecked when it was all assembled.

The rest of what can easily be fitted was bolted on ready for installation. Another mod that I have recently been looking into along with some friends was to add a supplementary oil supply to the main gallery at the front of the block - the idea being that it maintains equal oil pressure to all the main bearings. This is nothing new - we were just looking at a quick and easy way to try it. I wasn't going to fit it to my engine initially but following what we suspect to be front bearing failure (due to lack of oil pressure) on a friends car at the Silverstone trackday, I thought I might as well.

It's basically a feed from the oil filter housing directly to the front of the main oil gallery, It will be very difficult to establish if it makes any improvement but it should not have any detrimental effect, in theory it should help maintain an equal pressure along the gallery.

Next job was to get the engine back in, as the gearbox and bonnet are still fitted, I thought I would treat myself to an engine load leveller to aid re-fitting the engine - set off down to machine mart at 4:30 yesterday only to find they had sold the one they had that morning - sods law - not to worry, I have now ordered one off the Internet that should be here Tuesday (cheaper as well).

I will fit the front pulley when the engine is back in, I currently have it at work as I am using it to make a boss to hold a 36-1 trigger wheel for a friends EFi conversion. Next job is to start putting the throttle bodies back together, these were stripped so that they could be ported and matched to the heads, i was thinking about making some new spindles and fitting sealing bushes but this can wait as I need to get the car mot'd at the start of April.

Engine Stand

Following on from a question about my engine stand (another ebay bargain), here are a few pictures. I couldn't find a way of using the original brackets that came with the stand, they really needed to be mounted to the engine backplate - this doesn't help when you are trying to strip and rebuild an engine.

I have used the off side engine mounting bracket on the block with an additional 10mm steel plate, I offset the plate so that the centre of the stand is roughly in line with the middle of the block, this makes it very easy to rotate the block.

When fitting the engine to the stand, I found it easier to remove the rotating part of the stand along with the metal plate and fit this to the engine while it was being supported on the hoist, it was then just a case of lining the stand up with the mounting bracket spigot.

I did have concerns about the strength of the block casting, I initially trialled the brackets using a complete scrap 2500 engine with as much weight bolted to it as I could find, it all seemed to work ok but does become slightly more difficult to turn with a complete engine.

Other Stuff / Cooling

Well the cam didn't arrive so it was time to get on with a couple of other jobs, had an oil leak from the diff pinion seal so decided now was a good time to get that sorted. The diff was another ebay bargain, a Spitfire 3.89 picked up locally for £25 - should have really changed the seal before putting it in, I was more interested to see if it was a better ratio than the 3.63 that I had originally fitted. Removed the prop to make the job easier, this will also help when I refit the engine - should give me a bit of room to pull the gearbox back.

Thought I'd also record what I had previously done on the cooling system, my original radiator started leaking so I looked at what else could be fitted, its all quite tight but I eventually ended up using a Golf Mk II radiator, cost me £50 (new) with the fan temp switch (alloy matrix with plastic end tanks). It has four bosses on the front so I made up a frame which lined up with these and the original rad mounts on the chassis. The frame was also later used to mount the cooling fan and rad cowl.

Found this to be a good site for comparing rad sizes / outlet positions etc. etc. http://www.nissens.dk/uk/index.htm

I was already using an EWP (Electric Water Pump) so it was just a case of re-routing the bottom hose and turning the pump around. On the top hose I used a couple of 90 degree bends and some alloy tubing.

There is also an air bleed from the top of the rad, I routed this back to a custom made header tank mounted on the bulkhead - think this cost me about £40 of ebay.

The whole set up seemed to work ok last summer, the only mod was to add a resistor to the EWP controller to make it cut in at a lower engine temperature. I tested the system by giving the car a good blast down the motorway on one of our "hot summer days" and then parked it in the garage and left it idling for 30 minutes, between the pump and the fan the temperature was controlled at around 95 degrees. Under normal conditions it runs at around 85 to 90 degrees.

I may play around with the fan position to see if it makes any difference with the fan behind the radiator but to be honest it works ok at the moment and it is quite nice to have it all hidden away at the front.

One other point to make is that it is all quite tight to the bonnet line so if you are thinking of a similar conversion, you may need to adjust your bonnet to gain clearance.

Next job is to sort out a cold air intake, not sure if I'm going to stick with the standard plenum or go for filters fixed directly to the throttle bodies, this is something I will play around with if I get it on a rolling road later in the year.