Caddyshack

With the cost of YB 200 and 500 blocks seeming to be over £2k / £2500 it seems to me that the alloy blocks at £3500 plus VAT make a lot of sense when you can run 2.4. (especially as my 200 block and pistons / rods would have a value)

I guess with both builds you would be in for pistons and rods either way. Do the alloy blocks run just standard cranks, if so you might find there are savings although I suppose you might be daft not to run an arrow etc.

I have seen that the std head will fit the alloy blocks, I dont think I would run to the £6500 head at the moment So you would need the cams and head sorting.

I guess this would be a good 500 - 600 bhp option with the right size EFR? I would be limited to the 7670 I think as the next one up would take up too much room in my bay but at least I could re-use the manifold that Mark Shead had made and he thought my current turbo wouldnt have enough puff for a long stroke over 500bhp.

I am actually not chasing numbers as the 469bhp and 500 lbft that my car has is more than enough, I am just thinking about the potential rebuild of my engine and where best to spend the money, If I can get away with a refresh, long studs and cams / headwork then I would be happy.

Any thoughts?

ajamesc

Look about I paid 500 plus shipping for my 200 block from mt. Bore condition was of no concerne as with big power liners is better anyway.

lee2cossies

iTrader: (2)

Best speak to harvey at scs, i had a chat too him a while back about alloy blocks, definetly the way forward. The liners are only £100 each too if they ever need replacing, he has a few past 800hp and one at a 1000hp with no problems so far. im considering getting one as i want 700hp, it works out around £1400 to have a block nikasil linered and the same again if they need replacing so it makes sense long term, plus the cost of a 200 block on top, im sure he said 2.7 cc is a possiblilty as you can order them with a taller deck height too.

Caddyshack

Yes, the block does sound a lot but then when you factor in liners etc...it all gets a bit closer. I would want Mark Shead to build it. Anything over 600bhp would be too bonkers in my Pug as I can only get to about 205 tyre width and brakes that fit under 16's, I really dont want 17 inch wheels on a 205 shell. I would be more than happy with the max of 530 that my Turbo can run but a 2.4 / 2.7 would have the torque everywhere over the rev range and that is what makes a lovely road car IMO. I like the 25kg weight saving of the ally block as it is over the front axle. To be fair if my block is fine then it may be better to just use that but I want to avoid down time of the car so assembling bits first and then sell mine on after would save time.

Any thoughts on using the standard crank on any of these builds, be it std 2.0 or not if the target is under 600bhp. I know you can go for different stroke for better rod angles but wonder if that is better on higher rev engines or higher bhp?

If I could get away with just long studding my block, gas flow the head, pocketted pistons and cams then it neednt be a massive cost rebuild.

Oddly enough, I have put fresh oil in my car and fresh fuel and it seems to have cleared up a lot and only really smokes on start up cold map and sometimes when you give it a boot full on full boost and big revs. I can certainly soldier on for now.

lee2cossies

iTrader: (2)

If you are aiming for around 530hp im sure the 200 block will be fine even without liners.The standard crank are fine too, scs use them up to 700hp if unground, but again its a big risk due to their age and a new crank has many benefits just a little expensive. It would be best to call mark and have a chat to him if u want him to build your engine.

Mark Shead

Toby if you want to look at one I have two currently on the build stages now.

Mark

Caddyshack

Oh wow, Thanks. Maybe I can come and pick up,the viper when you are ready and I can have a look and ask you a few questions.

What crank will they use?

Mark Shead

Both on stock 2lt crank and bore size.

Mark

Caddyshack

So if I did go 2.4 or more then I might be able to use my crank if it is not too worn and just get Pistons for the bore? Would the rods need to be changed?

My engine has only done 36k from new so hopefully it will be fairly un worn with any luck.

Mark Shead

You can't go that big on bore so the crank would need to be changed. Even on my ultimate spec I would go no bigger than a 84mm crank and stock bore size.
I would also go for the tall block version if you have clearance with the bonnet.

Mark

Caddyshack

Ok, will need to speak to you more and hopefully put this off until everything else is sorted....all being well. You were right, my head gasket is a metal one

costina

iTrader: (1)

Imo its a no brainer not only do you have the weight saving also (i would guess) the alloy block and head combo will expand and contract at better rates than the cast iron and alloy head combo.

Win win.....

Caddyshack

It does seem to make a lot of sense and 20kg is a useful weight saving from the front of the car and quite high up. I can save another 20kg by matching the boot lid to my carbon bonnet., I don't have rear seats so it kind of helps make up for the 4wd system and small roll cage.

The pug 205 is only 870 kerb weight in standard form so if I can get close to 1000 /1100 kg I will be happy. I think a Saph 4x4 is about 1280kg?

smiley

My Mrs asked me "who's smith and Jones? " I said "why?"
She said "you were mumbling it in your sleep" 😂😂😂

Caddyshack

Better that than the blonde twins names from down the pub

smiley

Any pics?

Caddyshack

Yup, right up your 'alley'

Caddyshack

I have had a measure up and think I can easily fit the taller block, I will get it over to Mark to double check before I drop the dollars though. Also need to get my box in and 6 degree Beam in at same time as bladed arb splits to do first

smiley

only just seen that

Going for it then mate propper nuts 205 it will be

hq_

Apologies for resurrecting a thread from the past, but as it seems that at zero posts (and 6+ years of lurking after registering) I can't start a new thread, this might be the most relevant and least annoying way to do this.

In essence, I'm looking forward to building a large-displacement YB, tall deck alu block + stroker crank. I'm only aiming at between 500 and 600bhp, but I insist on having a broad powerband and good.. no, scratch that, great throttle response. Approximately 9-9.5:1 compression, twin scroll EFR7163 or 7670, E85 as a possibility. Probably with a (still experimental) diverting quick spool valve on a split (1+4/2+3) manifold.

What are my options for a 2.5l+, possibly even 2.6...2.7l bottom end? I know this won't be cheap when everything is said and done, but keeping it a bit more reasonable than writing an open cheque to a high-end engine builder sounds like a good plan at this point.

Caddyshack

Hi, speak to Mark Shead. He has a lot of experience but this turbos would be perfect on a 2.2 stroker. I think the 2.5 and higher are designed for naturally aspirated builds. 2.4 will rev less.

7064 is thought to maybe build too high back pressure on a 2.2 but should spool up in an amazing way. We are going to try it then upgrade to the bigger turbo. Throttle bodies should improve throttle response too. Mark shead head spec and cams worked brilliantly with a 2.0 recently and mine was great without head and cams. Can’t wait to try my stroker though.

smiley

As above really speak to somebody with experience in building and turning them budget for around 15k

hq_

Thanks for advice. The reason I'm asking because back in 1991 I had a very nice, all-custom stroker engine in my 2WD Sapphire. IIRC, ~90mm crank in a re-sleeved YBD block with ~94mm bore. It could spool an RS500 T04 like there's no tomorrow, but unfortunately it wasn't very long lived due to combination of extreme rod angles, very flat pistons and the limitations of the block itself. I stayed with stock displacement bottom ends with the Sapphire 4x4 and the Escort the following years but sort-of gave up on Cossies in '94 when the 4x4 was stolen and I finally sold the Escort.

Now that the "tribute car" 3dr RS500 replica is in the planning stage, all I really want from the engine is a massive midrange. Even more than the 2WD had, with a modern turbo. I don't care for a high-rpm screamer. A budget of 15k doesn't sound impossible at all.

I've just been wondering if someone, somewhere has already built a very large displacement turbo YB. There's no point in re-inventing the wheel, so an experienced YB engine builder might be the best way forward if 2.5l+(++) isn't common knowledge.

OTOH, the "smart" (read: cost-effective) move would be to use a completely different engine, a modern VVT/VCT 4-cyl like 2.0/2.3l Ecoboost stroked out to 2.6l (Esslinger) or even a V6, but the distinctive red cam cover is such a huge part of nostalgia that I'd hate to give up on the YB.

Caddyshack

I agree that there are better engines out there but the nostalgia is sooooo important, the cam cover is everything!

When I spoke to Mark Shead about strokers he felt that the sweet spot was 2.2ish and just worked best on the engine. With modern mapping, good fuels and a good twin scroll turbo on anything 2.2 to 2.4 I think it will exceed all expectations. The torque and mid range and response of the turbo would be great.

hq_

Just wondering... if 2.5l+ is more common with atmo YB:s, a slight compromise in piston height and/or rod angle might do the trick, with what's essentially an identical recipe. Modern dry liner alu blocks might be able to withstand abuse quite a bit better than the YBD could. Then again, I gave it absolutely no mercy so no wonder it blew up, with by far the most spectacular smoke screen I've ever seen an engine make. My later experiments with Nissan RB tall deck strokers have turned out great so it would be a shame not to use the same principles with the venerable YB.

We'll see.

Caddyshack

I know you can opt for up to 14mm block height and Mark was keen to use that if we had room when we discussed it. I do love the idea of a 2.5 to 2.7 Cossie with a nice turbo matched to it.