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3.0litre stroker crank set, k-jet fueled?

If I want to put 38mm exh valves in 531 head, need to cut valve seat?
Will 46mm intake valves be beneficial? What are the best springs to use untill say 6500rpm? With some 12.5 ish lift cam?
 
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The large size stock valve springs are ok till 6500rpm. I would cut the valves seats to be sure they have the optimal sealing surface but you don't have to replace the valve seats to run those size valves. Maybe get the KL racing valve springs?
 
I am asking because I read somewhere that springs form older B23/21 heads have stiffer springs? I have some of those wondering around, so was thinking to use those?
You can use those for the stiffer springs, I measured all of them a few months ago as well as the kit's I got from KG. The stock larger springs achieve 380N clamping, ideally you'd be at 500-600N

 
My machine shop used the larger B21FT stock springs when he rebuilt the 405 head on my car. He shimmed them and told me I can safely go to 6800rpms. I've accidently gone to 7k and it was ok with it but I try not to go over 6500 most of the time. I use a V15T cam with it and it's been fine for many years now. Stock valves with turbo exhaust valves added. You can see the specs on gsellstrm thread on head flow spread sheet. Edit, It's a kjet 405 head from a B23E in Canada.
 
I am asking because I read somewhere that springs form older B23/21 heads have stiffer springs? I have some of those wondering around, so was thinking to use those?
The KL Racing single spring kit with steel retainers is a great option. The larger diameter original springs get soft after many miles, new small diameter springs are more stiff than used large diameter springs when I’ve measured them.

It’s common for people to use the large diameter spring retainers and locators with vw type-1 aircooled springs. So that’s an option as well.
 
Culberro has a point. My original 160 head floated a no 2 intake valve around 275k miles when I over revved it. So they lasted pretty long but at that point I knew it was time for the better head on the engine. 8-)
 
Mr. Swedbrick convinced me of buying his valve springs, 46mm intakes and H cam.. :) So that solved quite some questions.

So set up looks like set up will be something like;
- 3 liter bottom end
- 531 head gently ported
- 38/46 valves with 520N springs
- H - cam Kyrk Motorsport KY 126 13.1mm lift 275 duration
- 48 mm webers
- Flat flywheel, on diet, with Saab performance press plate, organic NOS 215mm drive plate.
- Leaky M46
- Freshly painted eikers
 
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I would suggest the 240mm Saab pressure plate. There's going to be a lot of torque from your engine. It fits the flat flywheel if you move the dowels and there is a thread on spacing the pivot ball in the bell housing for the clutch arm.
 
Using kyrk motorsport KY 126 13.1mm lift 275 duration.
He says it will work with stock tappet.
Also some springs coming and 46mm intakes.

Anything special I need to be aware off? Valve guides length maybe?
 
Using kyrk motorsport KY 126 13.1mm lift 275 duration.
He says it will work with stock tappet.
Also some springs coming and 46mm intakes.

Anything special I need to be aware off? Valve guides length maybe?
Valve guide length shouldn’t be an issue with that amount of lift.
 
I found that with the double valve spring retainers, 13mm was the maximum clearance to them, so for those beware
That's really good to know! Which retainers, the KL Racing ones? I'm so used to using the retainer and seal combo that I source, which offers a decent amount of clearance at those lifts (13-13.5mm when used with OEM seals).

Was it 13mm of lift before the retainer hit the guide or the seal? Or was that "13mm" with a 1-2mm safety margin?
 
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That's really good to know! Which retainers, the KL Racing ones? I'm so used to using the retainer and seal combo that I source, which offers a decent amount of clearance at those lifts (13-13.5mm when used with OEM seals).

Was it 13mm of lift before the retainer hit the guide or the seal? Or was that "13mm" with a 1-2mm safety margin?

The KG trimming retainers, I did the check for my RSI stage 3 cam with 12mm lift because I was unsure it would work. The intake side has a bit more clearance if you are comfortable without the seals, but I found the exhaust to be really close.

I'll take a picture of my measurements tomorrow, they should still be on the whiteboard. Basically took the difference between the measurement from the top of the retainer to the baseline of the camshaft journals, with and without spring, the second dropping the retainer until it landed on the valve stem.
 
While sitting on board my m8 already stripped the donor engine down for me.
Looks like its last oil change was in 1869.

The seller promosised me that it would be a '95 b230f but seems pre '93 since the squerterers are missing in action.
Have just requested some BMW squirterters at my m8 who's working in BMW.
Luckily it has 63mm mains though :) otherwise the crank wouldn't fit.

So engine should go to workshop 2morrow for boring it up to 96.4 and decking it 1.3mm.

Squirters will be installed after I get home, I made the tools already earlier for another build so shouldn't be to difficult to get them in.

Edit:

If someone in dutchie country or near is in need of engine parts I have some :p
 

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