GTA hillclimbmonster

Turbohead,
Where did you buy your 321 stainless pipe & slip joints...looking at rebuilding my manifolds with 316 flanges & 321 pipework.
Cheers Eddie.

Hi Eddie,

Burns stainless (USA). Actually very expensive stuff, but worth the price
I was ending there after an odyssey of suppliers and tube diameters.
You should be able to get pipe stuff from your local steel supplier, if you have an option to bend them. But as i've needed pretty concrete diameters and ratios from primaries to secondaries they are calculated to suit the turbo we'll fit, and the heads, gas amount for the numbers i'm aiming and beeing not too big to increase lag and unnecessary heat transmitting surface, and smooth bends, and and... actually a sience at its own as you surely know.
The 3 in 1 merges are a very critical part. Keep angles very smooth, look that you have no steps anywhere disturbing the flow, i've seen sheets that prove how much power you can loose not beeing carfully on the inside.
And take care because of heat expansion, can be up to 9mm by a 1000mm tube from cold to racing heat!
That's why i go for the double slip connections and v-bands, +merges welded by Burns. The rest...TIG welding slowly with little amps! Say 30 on a 1.6mm tube. And take weldings with higher spec, best is very thin TIG TR 347.


!!!

Hmm actually you wanted just to know where i have them from, and surely already know the rest. But maybe it gives a little help to someone else somwhere, once....

Turbohead, thanks for the info...I have been on the Burns site & done the calculations...I just thought you may have found a supplier in Europe for the 321..keep up the good work.
Cheers Eddie.

Go for them! They do a brilliant service, shipping was very quickly.
Worked much better then the things with most of the european folks!

Eddie,
Just to add, maybe you already know. If you search in Europe, look for the norms 1.4541, that's simmilar to 321.
1.4571 is also good, but the 1.4541(321) is a bit more flexible especially on thin wall tubes and under the conditions of repeatet heat and down cooling periods.
I take 1.4571 for the turbo-collector tubes, but in 2.7mm wall.
The 1.4571 is able to resist more heat.

And as you say 316 good for the flanges, less heat transfer, and aviable around the corner.

Hi Chris

Hope you are out there enjoying your holidays! Well, when you catch up I have developed the port and happy with the overall result - bulk flow, flow down force (cylinder filling), and mixture motion (wet flow)... results look like this (.. and that's my best reworked 46mm inlet valve 3ltr head by comparison, not the OE 3ltr head performance):



I'm quite pleased with the that given the complexity and extreme care needed with the 2.5ltr port SSR compared the 3ltr.

Martin

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Well Chris.. my test pattern port for your heads got the seal of approval from Mr. Vizard himself, don't get much better than that sir...

Hi Martin!

Holidays where... well Actually not to return would have been better decision!

Brilliant results from your work!!! Sounds great! Good motivation to go on with the manifolds, thank you! Approval from Mr. Vizard !!! How was it? Learned some interesting things, or have you already known what he was telling?

Kind regards
Chris

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Well Hi Chris... progress!

So I thought I would take up baking, and into the mix goes…

Balanced 63mm crank, with some H beam rods and special pistons that will come in the story later, lots of balancing holes as the rod and piston combination is much lighter… this is all pre cleaning…



Rub rub..



tap tap.. trusty blunt tap for thread cleaning, want those head bolt stretch / strains to be consistent…





Checking liner heights and position before clean down, before building back up with known positions, liner seals etc…



Checking main cap alignment with bore gauge (as per method page 1 here: viewtopic.php?f=8&t=5612), and main cap indexing / reference surface ie which side of the block to push them on assembly – two middle saddles are clamped and reference fit in the block, front and rear is typically not. I have had this block line honed through the saddles and replicating the setup when this machining operation was performed is important; it gives a little extra oil reservoir at the bearing parting lines if done correctly with some tweaks. The PRV is typically tight on this dimension deliberately to reduce engine running noise; in this application I’m not at all worried about that.





Various checks before fine clean and build:









Checking liners free fitted..



Bottom, to:



Top (apologise for the Chinese gauge, it’s my back up, my lovely old British gauge is having new jewels fitted as I dropped it badly when I first started on this engine build.. hey ho, but this is a trusty unit, and null movement on any gauge is the best / most accurate point, these liners post boring (no this isn’t standard bore size anymore… ) and honing are spot on!)



.. and then, checking the liners under torque plate to check taper and ovality, and set final position / tweaks etc.





Scrub scrub..





Uprated version of the shells goes in, comparison of some old units as below:

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To give the basis of the spec, as you would have seen from the above, the block is a later cross-bolted main centre cap. This is by far the best block to have, this one does not have the oil sprays and does not need them, and in fact for the intended short sprint / hill climb application pretty much undesirable – just adds additional oil loading to the rings to control – oil in the chamber reduces the detonation limit. Given the short sprint application then ability to spin the revs up quickly, get the turbo on spool is paramount. The crank has been kept to the 2.5ltr, as it is more durable and forgiving with oil starvation from oil surge or such issue (see my comments on cranks in my Boneyard thread), and much lighter than the 3ltr even-fire. The rods and pistons have been upgraded from OE items, to H-beam rods and forged pistons. The liners are bored and honed 2.5ltr versions from the later “thick” liner series as they were effectively the 3ltr liner finished to a nominal 91mm bore instead of the 93mm bore at the Douvrin factory. The rebore has been kept down to limits to match the capacity class, clean up the bore leaving opportunity for later rebores, and keep the liner wall thickness at a maximum to retain the added rigidity; important for the ultimate ring seal when pushing the turbo over-pressure. More to be covered later.. I’ll probably put the head mods and valve gear changes on my Boneyard thread

Chris, can you post up your turbo spec again please, time to check whether it’s going to be substantial enough!

Prooogggrreeessss!!! Dancing on my chair !
Seems that i should go on with the manifold work quickly!!!
Turbo spec i'll have a look at what i have, too long ago, will post answer next week!
Thanks Martin for the interesting and very important details you are posting. Looking so forward to hear it running!

This is becoming a great thread....

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Thanks Rupert, it's going to be quite an experimental engine as you will see as it unfolds, so it may even go bang at the end of it... will see

Martin,
Are you going to be using a winged door type sump baffle to prevent oil surge on this engine.
CheersEddie.

Nice!

Looking forward to seeing more of the build.

Cheers,

John.