107 replies to this topic

[stoneface]

Amazing work and dedication.

Would love to know if you plan to make more and make them available?

[Ronski]

Very impressive work, subscribed.

[no66]

This together with a Specialist components 5 bearing block   

Joking aside, would also like to know if there are any plans for more to be made?

[Norway Thomas]

 

It would be interesting to know what a camshaft, head, manifolds, thermostat housing etc would cost.

I regret mentioning the fan being on backwards but one was asked to spot the deliberate mistake.

Like others I am might impressed by the work put into this.

 

Truth is I hadn't realized the fan was on backwards! The deliberate mistake was the dip stick! which is now fixed, and came out really well and very easily too. Sometime you get a win!

 

It's too early for costs! Cam and Exhaust are off the shelf. If I do make some the cost will depend on the quantity made...

 

And don't forget standard A+ Rods don't clear an 8 port cam! Bet you didn't know that I was halfway through this before I found out, S rods can be modified a bit to clear but if you go A+ then you need new "competition" rods with bolts rather than the stud and nut on the standard rods.

 

Thanks for that info :)

If I were to go this route I would likely opt for the best aftermarket rods, the cams available for the 8 port heads that are available seem quite extreme for what will likely be a road engine.

It is pipe dreams at the moment, lets get the rust sorted first.

[Spider]

 

And don't forget standard A+ Rods don't clear an 8 port cam! Bet you didn't know that I was halfway through this before I found out, S rods can be modified a bit to clear but if you go A+ then you need new "competition" rods with bolts rather than the stud and nut on the standard rods.

 

 

This occurred to me when I saw the Combustion Chambers and the Valve Layout.

 

Would it not be possible to 'mirror' Cambers and Valve Arrangements for Cylinders 2 and 4 ?  I do realise this is a very simple question that has huge implications elsewhere in the design.

 

It not only gets around this issue, but it then also goes back to the more normal Camshaft arrangement and a much much wider variety of off the shelf Cam grinds, other than 'Full Race' and 'Sprint' grinds.

[Trog]

 

 

And don't forget standard A+ Rods don't clear an 8 port cam! Bet you didn't know that I was halfway through this before I found out, S rods can be modified a bit to clear but if you go A+ then you need new "competition" rods with bolts rather than the stud and nut on the standard rods.

 

 

This occurred to me when I saw the Combustion Chambers and the Valve Layout.

 

Would it not be possible to 'mirror' Cambers and Valve Arrangements for Cylinders 2 and 4 ?  I do realise this is a very simple question that has huge implications elsewhere in the design.

 

It not only gets around this issue, but it then also goes back to the more normal Camshaft arrangement and a much much wider variety of off the shelf Cam grinds, other than 'Full Race' and 'Sprint' grinds.

 

 

 

 

This is what all the 7 port heads do, Idea being you can bolt it straight on, and even use the old exhaust system.

 

But it comes at a price, the inlet ports are not ideal, and exit the head in pairs 1/2 & 3/4, which means they can "scavenge" from each other, or you have to make rather serpentine ports! But the bigger issue is the exhausts, namely 3/4 which are Siamese'd on the standard head, It's very hard to make these separate ports, Ken Eldar tried it but the ports were a dogleg shape and compromised (No criticism meant!) I have seen one other design (for a 1000 cc. engine) that used a steel divider to make it 8 port, but again a compromise as you are squeezing 2 ports through one push-rod gap.

 

For the sake of a cam and and exhaust manifold (and a set of rods!) I didn't think these compromises worth it when an 8 port can give you so so much better ports. "Why have 7 when you can have 8"!

 

WRT the cam Swiftune will make me an 8 port with any of their grinds on (from a billet, but then they all are these days, for 25 quid more than a standard cam (One off set up fee I guess) so not a major issue for me. I will be getting a fast road cam off them when the time comes.

[Trog]

Thinking of Rods, 

 

The "problem" I have is I am only building a fast road engine. Standard rods are more than enough for this, you only need new rods for much higher output engines... So of course they are very high spec and expensive and overkill for what I am doing. I have seen the Maxspeeding rods but am I prepared to risk an engine and (5 speed) gearbox to save a few hundred bucks? No is the simple answer. I have looked into this a lot, I like the Minispares I beam rods but will probably go with the SC H beam rods as they are a better price. 

 

Would be interested in thoughts from those with more experience of this than me, so any engine Gurus out there?

[GraemeC]

What bore size are you looking at? The SC rods are quite wide and do sometimes catch the bottom of the bores:

http://mk1-forum.net...php?f=5&t=27556

[Trog]

Chapter 5 “Can’t think of a quote”

 

At the beginning of this story I said how I had not been able to get a copy of any Leyland drawings. As I was working through this project, I found that I could reverse engineer about 90% of the data I needed. Another 9% could be found on the ‘net. But that last 1% was a bit of a problem. Specifically, the fit between the guides and head… So, I asked for some help on the Ausmini forum and got some feedback from “winabbey” who had a copy of the head drawing and was happy to share it with me!!! Wish I had asked for help on the Ausmini forum earlier! Ironically this did not have that one piece of info I needed but it did let me check a lot of my reverse engineering and helped to get the machining a whole lot better. (I did find the tolerance I needed in the end; more later) The first thing I did was compare the head stud, valve guide and pushrod hole patterns with the drawing. I wasn’t too far off, all within +/-0.5mm. of the Leyland drawing, but I still corrected everything to the exact spec. Ironically, I had just had a 6 mm ally plate laser cut to confirm the fit of the head to block… It did fit so I was within the tolerance of the oversized head stud holes.

 

For reference the “front centre” stud (between 2 & 3 spark plugs) is a sized hole, all others are over-sized. When fitted the head can move about this stud. (Do any of us take the time to get the head as straight as possible on the block!) When you think that modern heads are located with dowels etc. this is a bit surprising but made the head a whole lot easier to make as my positional tolerances could be a bit looser.

 

I have very little machining experience and no equipment so this was never going to be something I could do myself. Luckily, I have a colleague who does and has! And would do it at very reasonable Mates Rates. I gave him the CAD, a set of my drawings, a copy of the Leyland drawing and of course the castings.

 

This was his initial 11 steps to happiness:

 

 Machining 1.JPG   68.16K   5 downloads

 Machining 2.JPG   18.27K   16 downloads

 

Couple of things that changed, firstly he didn’t need to counter bore the plug holes, and there is an oil way drilling missing. But it should give you an idea of the amount of machining required for what is a very simple head! (Imagine a twin cam like KAD’s) In reality fact he did not do all of each step at the same time.

 

We also discussed reaming for the guides and cutting and fitting the Exhaust seat inserts and agreed that this was something that I would give to a professional engine reconditioning company as they would have the experience and correct equipment to do the job correctly.

 

If you remember the casting images; we had some casting defects on the main face, as we machined the head they all disappeared except one which turned out to be a hole into the water jacket. This was a real surprise and a downer. However, a bottle of wine (or two) later we thought about it and realised it was not over the compression ring or the combustion chamber so we felt it could be brazed up later. Actually; it is where there is a brass insert on the 1275 head to cover a core venting riser, I thought I had given the sand cores enough venting routes through the water jacket holes but apparently not. If I did more castings I would add a vent there, just like BMC did… Hmmm.

 

 Slide1.JPG   49.08K   14 downloads

 Slide2.JPG   48.62K   11 downloads

 Slide3.JPG   58.87K   5 downloads

 Slide4.JPG   54.51K   10 downloads

 Slide5.JPG   56.43K   7 downloads

 Slide6.JPG   46.7K   6 downloads

 Slide7.JPG   62.19K   6 downloads

 Slide8.JPG   54.19K   8 downloads

 Slide9.JPG   63.52K   9 downloads

 

Nearly finished now just needed to get the guides fitted…

 

 

 

[Pops_Guild]

Finally got to read this thread. Amazing read and amazing work! Thank you for find the time to share all the info with the community too.

[mini13]

I'm using the sc rods and happy with them, but I'm only running a turbo lump so 7.5k max... Although there are plans to up this.

Are S rods an option for you? As I know these used to be the go to for 8 ports back in the day.

[Spider]

Thanks for your reply re: Changing the head chambers around. Copy on all that and I do appreciate that nothing s simple, especially when some say 'why don't you,,,,,'. I asked as while I realise that just about any Cam profile you want can be ground, it might have addressed this issue (below), which there is a solution to, but not cheap,,,

 

Thinking of Rods, 

 

The "problem" I have is I am only building a fast road engine. Standard rods are more than enough for this, you only need new rods for much higher output engines... So of course they are very high spec and expensive and overkill for what I am doing. I have seen the Maxspeeding rods but am I prepared to risk an engine and (5 speed) gearbox to save a few hundred bucks? No is the simple answer. I have looked into this a lot, I like the Minispares I beam rods but will probably go with the SC H beam rods as they are a better price. 

 

Would be interested in thoughts from those with more experience of this than me, so any engine Gurus out there?

I'd only use Carrillo or Arrow Rods. The consequences of failure are just to high to think about.

 

 

Oh and the Bore dia in the heads for the standard guides is 0.469"

[Mr Joshua]

Take a bow son take a bow

[AKat]

Haha, this is great!  You beat me to it!  My criteria were slightly different to yours though (small bore).  Mine were

• Has to be compatible with standard manifolds
• Has to be compatible with standard cam layout
• Has to out-perform a standard 12G295 casting by a minimum 25%
• Has to be cost effective (where it fell on its knees)

 

 

I applied modern port design data to it, used modern standards for CSA and port taper.  The prototype did outflow the 295 substantially above 0.060" (below that it was too hard to tell because of the valve seat... subsequent designs I've done I've actually inserted a steel seat into it so that I can use proper seat angles). 

When I worked out the cost to produce I realised that people probably weren't going to want to pay for it.

Interesting that we both ended up with a chamber not too dissimilar from the stock one, with the space available and other constraints it was hard to beat that basic love heart shape! 

Love your work mate! 

 

 

 

[Trog]

Haha, this is great!  You beat me to it!  My criteria were slightly different to yours though (small bore).  Mine were

• Has to be compatible with standard manifolds
• Has to be compatible with standard cam layout
• Has to out-perform a standard 12G295 casting by a minimum 25%
• Has to be cost effective (where it fell on its knees)

(Pictures Deleted as everyone's just seen them!!!)

 

 

I applied modern port design data to it, used modern standards for CSA and port taper.  The prototype did outflow the 295 substantially above 0.060" (below that it was too hard to tell because of the valve seat... subsequent designs I've done I've actually inserted a steel seat into it so that I can use proper seat angles). 

When I worked out the cost to produce I realised that people probably weren't going to want to pay for it.

Interesting that we both ended up with a chamber not too dissimilar from the stock one, with the space available and other constraints it was hard to beat that basic love heart shape! 

Love your work mate! 

 

 

Really lovely work, not seen anything like this before, really clever original thinking. I find it really interesting to see how different people come up with so many different solutions to what is basically the same starting point: "I want better performance from the cylinder head" like you say you started with some very different criteria so you have come up with a very different and ingenious solution. 

 

Can I ask; with the exhaust ports, are they water cooled over the top or are you relying on oil cooling? When I looked at up-drafting the exhausts, like you have, I couldn't get any water jacket over the top. Also before someone else asks are you going Iron or ally on this?

 

I understand what you mean about production costs, I am not sure whether I can make a cost effective product either, and I think costs out here are cheaper than the UK. It all depends what people are prepaired to pay of course!

 

So are  you going to take this further (You really should!)? Will it be cast or machined from solid? If you are casting do look into 3D printing, at least for your first prototypes as It can get you a very accurate part quickly and at a very reasonable cost.

 

But far more importantly; you can go into your workshop without shoes on? If I did that I would end up in A&E having my paws stitched up...

 

Good luck and keep going! (and don't forget to add some spark plugs...)