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531 vs 530 head

b_carlson

New member
Joined
Mar 26, 2013
I've read that the 531 head supposedly flows better on the intake side. But with identical exhaust. I currently own a SCP 530 head but have the oppurtunity to purchase a 531 for a very good price. My plan is to port whichever head out that I end up using, installing larger valves etc. My question is will both heads have the same maximum potential or will the 531 still come out on top at the end of the day. After I put all of the time and money into a head, I want the best I can get.

Thanks
Ben
 
with just minimal clean up there's no difference.. Doing more like actual "porting" and there's no point in wasting money on the 531..
Only time a 531 and its 1-2% max flow means anything is if you're building a car for Volvo Original Cup where you can't touch the ports..

Going to be n.a or turbo?
 
i seem to remember that there is also a slight difference in combustion chamber volume, 530 being slightly smaller so will result in slightly higher CR when installed on the same shortblock. Don't ask me numbers, i don't know because to long ago.
 
531 chamber is 2cc larger, spark plug location is different as well.

I have a 531 at a machine shop, I wouldn't have spent a bunch of money on it but if it's free/cheap why not start with the best platform. Do some googling the differences are nicely documented.
 
As far as i remember the 531 has a spot with much less meat which could cause troubles when doing serious portingjobs and larger valves...
 
531 chamber is 2cc larger, spark plug location is different as well.

I have a 531 at a machine shop, I wouldn't have spent a bunch of money on it but if it's free/cheap why not start with the best platform. Do some googling the differences are nicely documented.

Muchachito, everybody always sayz " spark plug location is different"...

I just was looking at that 531 that RSI jerked the guy around for 15mo and wrecked--for $2000 ----and stonewalled him afterward and although the gigantor HUGE chambers were obvious, the "different" spark plug location wasn't.

EVERYBODY that buys the whole 531 thing ALWAYS says that. But NEVER any a) comparison or b) allegations of the significance of, or c) HOW MUCH different..

Cause it wasn't noticeable.

You think it's meaningful? measurable? I don't know. What do you think? Asking cause you might have a better eye since you know waht real excellent heads look like (and they don't have any holes except ONE spark plug hole right up in the top.)
 
I have access to a pile of 531's near me. Boat wrecking yards are a VERY good place to find them. Only reason I would pick one up is if the 530 on my car needed work for whatever reason. It's not the unicorn people make it out to be. If you get a good deal on one then no reason not too.

Just FYI if anyone wants one the guy said 250$ with a clean bill of health. Don't know what that means to him but ehh.... Someone wants one send me the money and pay the shipping and I'll get it to you.
 
i seem to remember that there is also a slight difference in combustion chamber volume, 530 being slightly smaller so will result in slightly higher CR when installed on the same shortblock. Don't ask me numbers, i don't know because to long ago.

At this pint in World History, we should probably say "the 5XX was originally CAST with chamber Xcc less--but 25-28 years later who can begin to say what the chamber volume is now...so that difference is how you say in SoCal? Oh yeah...that difference is "Like, whateveah"

So much of the writing here is too vague, sloppy and lazy and therefore useless...
You're a sharp guy, you could help out in helping the poor innocents that read this bordell and who must try and make sense.
Please.:please:
 
Jeez just port what you have. It's going to free up more than enough air flow. Can be ported to way more than any red block will need. These cars are getting 350-400hp standard. Ports.are just going to raise that to a higher rpm if you go cam and springs. Go cam and springs and then worry about port when you want over 400
 
Muchachito, everybody always sayz " spark plug location is different"...

I just was looking at that 531 that RSI jerked the guy around for 15mo and wrecked--for $2000 ----and stonewalled him afterward and although the gigantor HUGE chambers were obvious, the "different" spark plug location wasn't.

I won't lie, I haven't had the 531 next to a 530 yet, so I must admit I'm just repeating what I've read. I was kinda believing this site since it's at least got some documentation, but I'll have to look and see for myself (once the machine shop wakes up and tests the thing for me).

http://people.physics.anu.edu.au/~amh110/Head/cylinder_head_531_530.htm
 
Well, moot point for me. Just rapped with the machine shop and it's going to cost too much to get my 531 cleaned up to make sense (pitted gasket surface and typically crummy #4), so I think I'll end up putting the money towards getting a 530 worked a bit. I certainly would have liked to start with a 531, but if it costs hundreds of $'s just to get it to "clean core" status it hardly seems like a wise move.
 
This is a funny thread. Not once was the key thing that makes the 531 intake side better mentioned, or conversely what makes the exhaust sides of both suck!

The exhaust short side radius on these heads SUCK! This is where the 531 got it right on the intake side, but left the exhaust side as is.

If you're dedicated to using an 8V head (A'la Bamse), and dont' mind spending money or doing it yourself, raise and shape the port floors. This has everything to do with preventing boundary layer separation.
 
http://forums.turbobricks.com/showthread.php?t=232036

Keep your 530/398scp if you are in a turbo car.

Good on your for posting that thread, but it's not as simple as that.

This is the key right here....

A well ported/filled 530 will make more power than a 531 anyday with a cam under 12.5mm.

.... to which I say, "of course". And RSI were (who knows what's going on there these days) prolly doing this on both the intake and exhaust sides. Remember the 531 has the same garbage short side radius as the 530.

However, this is TB. People would rather put on bone yard 16V's then spend real money on a built 8v.
 
Well, moot point for me. Just rapped with the machine shop and it's going to cost too much to get my 531 cleaned up to make sense (pitted gasket surface and typically crummy #4), so I think I'll end up putting the money towards getting a 530 worked a bit. I certainly would have liked to start with a 531, but if it costs hundreds of $'s just to get it to "clean core" status it hardly seems like a wise move.

'xactly
 
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