Split 405/531 head pics. [Archive]

Morley

11-07-2005, 01:55 PM

This is what you've been looking for, I think. Hope it's not a repost, they're shamelessly stolen from a Swedish website. (Savarturbo)

The intake.

http://home.minlos.no/~audun.skripeland/Topp/405_in_std.jpg

The exhaust.

http://home.minlos.no/~audun.skripeland/Topp/405_ut_std.jpg

I think anybody is able to see how fubar the exhaust port is now, and why the Swedes call this head the "swan-neck" head.

dl242gt

11-07-2005, 02:02 PM

Thanks Morley, that's a great to be able to see what's good
and what isn't. I think I can see why the large coolant passages
made the head weak under high boost. Especially on the intake
side. The guy that worked over my cylinder head told me the
exhaust port would work better if he could have it come out of
the cylinder more vertical then have the passage turn toward
the port.

Best regards,

isaac

11-07-2005, 02:30 PM

Makes you wonder if maybe raising the exhaust port floor, slicing the crap out of the port roof, and somehow filling the hole up there would work wonders.

Slice a straight line through that hump at the bottom of the intake port and fill that in too, then see what happens. That'd be badass.

Morley

11-07-2005, 02:32 PM

Makes you wonder if maybe raising the exhaust port floor, slicing the crap out of the port roof, and somehow filling the hole up there would work wonders.

Yes. They do that, weld weld weld weld. SCP heads have a great advantage here. Not allowed in a lot of racing classes though. (The welding)

Slice a straight line through that hump at the bottom of the intake port and fill that in too, then see what happens. That'd be badass.

+1

linuxman51

11-07-2005, 02:36 PM

got any of a 531 with its coolant passages? :)

Morley

11-07-2005, 02:36 PM

got any of a 531 with its coolant passages? :)

Noes.:-(

Morley

11-07-2005, 02:37 PM

As far as I can see, there's a lot of potential on the intake, when you're using a head without injector holes. The exhaust is, fubar.

blkaplan

11-07-2005, 02:42 PM

i think mikep has a junk 531 head that has either cut up or was thinking about cutting up...

maybe he will chime in

mAydAy

11-07-2005, 05:16 PM

It'd be awesome to get all of them up there....160, 398, 530, 531....BCP (Where applicable) and SCP. Its alot to ask for, but if people just can pick up a junk head now and then we could get it together, or just find some pictures online. It'd be extremely beneficial for seeing porting potential and weak spots and stuff.

I'm assuming thats a BCP head.

Mike has a 531 that is correded on #4 I'm pretty sure, don't think he's gotten around to cutting it though.

Captain Bondo

11-07-2005, 05:39 PM

Slice a straight line through that hump at the bottom of the intake port and fill that in too, then see what happens. That'd be badass.

Huh? People actually go to a lot of effort to ADD a "hump" like that to ports that look like the exhaust port.Cutting it off would actually make it worse. That hump is what is keeping the shortside radius reasonably large. The goal is to "straigten" the port- trimming that lump off would add a ton of port volume (which is bad) and not help flow. Basically, you'd make it look like the exhaust port.

Honestly I don't see anywhere material really needs to be removed on the intake side except for a little bit in the bowl. I think it might be worth making the part of the casting that directs air around the valve stem (the "sharkfin") more "sharkfin-like" and blending that into the bowl/seat, but that's it.

The exhaust port looks hard to fix without raising the port floor at the shortside radius.

Neil Peart

11-07-2005, 05:47 PM

kyle242gt

11-07-2005, 05:49 PM

I think it might be worth making the part of the casting that directs air around the valve stem (the "sharkfin") more "sharkfin-like" and blending that into the bowl/seat, but that's it.
Does that mean that the apparent narrowing of the port leading up to the valve guide is just a ridge?

towerymt

11-07-2005, 09:34 PM

Mike has a 531 that is correded on #4 I'm pretty sure, don't think he's gotten around to cutting it though.
Heavily cracked. It ain't makin a comeback. Chop it.

Captain Bondo

11-07-2005, 09:44 PM

Does that mean that the apparent narrowing of the port leading up to the valve guide is just a ridge?

Yes, the "narrowing" is somewhat misleading at first glance because there is what is more like an "island" of aluminum around the valve guide that serves to help direct air around it and the valve stem. :)

The Aspirator

11-07-2005, 10:05 PM

Kyle, here ya go. This is the "sharkfin" that 405 and 531 heads have on the intake side. I've seen a lot of swedes chop down the valve guide and sharpen the fin like crazy. It tries to smooth the flow of air around the valve and valve stem, and in stock form I'm sure it does a better job than a head without it!
http://www.j2mediagroup.com/john/405-05.jpg

Great pictures guys! Can somebody confirm if that is a BCP or an SCP head? The actual opening near the deck does look really small, but it's hard to judge from a picture like that. The biggest problem with BCP heads is that they don't clamp onto the headgasket nearly as well, so high boost will shoot the fire ring basically into the coolant passage.

For the exhaust ports, could you grind the valve guide smooth and raise the roof a few mm? That would certainly make it a larger radius and probably help with flow direction alot. Wow it's just really interesting to look at those pics! "The anatomy of a volvo cylinder head".

mikep

11-07-2005, 10:08 PM

The bandsaw took a dump. Time for the chop saw? I have 530, 531, 398, 160.

Bondo is right, that exhaust floor needs to come up.

coldfusion21

11-07-2005, 11:09 PM

i have a 530, and maybe a 398 that i would be willing to chop. need to find a valve spring compressor first tho...

isaac

11-07-2005, 11:36 PM

Huh?

What?

So if you filled in the intake port floor ahead of the hump, then sliced the living crap out of the port on top - where the injector would not be on a 530/531 (and some 160/398) head - then you could jack the intake port angle by quite a few degrees. That'd be swiz.

Matt Dupuis

11-07-2005, 11:52 PM

Like they did with turbocontainer'n, in Off Topic.

I have pix of a BCP 398 laying around somewhere - have to find 'em but they may be lost forever, along with tons of other stuff that's stuck on a possibly bad CDR.

isaac

11-08-2005, 12:36 AM

This is what I meant, Kenny:

Intake:
http://upload.pbase.com/volvoisaac/image/51960765/original.jpg

Exhaust:
http://www.pbase.com/volvoisaac/image/51960724.jpg
and yeah that definitely took some doin to make those happen, so I'd say I've done well with PS-porting.

Canuckvolvo

11-08-2005, 12:56 AM

I have pix of a BCP 398 laying around somewhere - have to find 'em but they may be lost forever, along with tons of other stuff that's stuck on a possibly bad CDR.
I only seem to have the exhaust shot, not sure what I did with the intake. Too bad since that's where the major difference is between the heads.
Top is the stock 398 (SCP Matt? Dale?) exhaust port. Below is one I photochopped with the idea of getting some smootherer flow:
http://www3.telus.net/athal/volvo/398 exhaust port b4 and after.jpg

Greg Wong

11-08-2005, 01:00 AM

Big pics, I don't really feel like resizing them, sorry. These are from Philip Bradley, I think the machine shop in New Hampshire sectioned these to find out how much they could port his head. 398.

<img src="http://users.norwoodlight.com/gwong/398exh1.jpg">

<img src="http://users.norwoodlight.com/gwong/398int1.jpg">

towerymt

11-08-2005, 03:10 AM

I only seem to have the exhaust shot, not sure what I did with the intake. Too bad since that's where the major difference is between the heads.
Top is the stock 398 (SCP Matt? Dale?) exhaust port. Below is one I photochopped with the idea of getting some smootherer flow:
http://www3.telus.net/athal/volvo/398 exhaust port b4 and after.jpg
Could you remove material and get the same effect?
http://mason.gmu.edu/~mtowery/398_exhaust_port.jpg

Wagner

11-08-2005, 03:48 AM

Could you remove material and get the same effect?

Every expert, who knows their stuff about volvo heads, i've ever spoken to about these heads have always said "do not touch the exhaust passage floor at all, as it will kill the flow".

I've never questioned that, but now i'm interested too.

Although, most of the flow does take place in the upper part of the channel, and maybe that hump will be too far off to be effective if done by removing material.

Matt Dupuis

11-08-2005, 10:32 AM

Athal and Greg, thanks - those are mine.

As you can see on the exhaust ports, the 398 and 405 are most definitely DIFFERENT in the area right around the exhaust valve.

Yeah, Mike - never remove material from the floor. Only add to it. Athal's got the idea but hasn't taken it far enough, IMO - you've got to add to the floor and smallen up that cavernous exhaust port. Make the floor roughly parallel with the roof, and even remove some mat'l from the roof. Kinda like what Isaac did with his bitchin' pshap.

PRVersion

11-08-2005, 12:16 PM

I could get this done it the matter of a week.

I could even do OHV heads ;-)

pleeeeaaaaaase do. :badboy:

Stereophile33

11-08-2005, 12:37 PM

I think this discussion could benefit from Yea Right's thoughts.

Peter spents thousands and many hours of work bench testing heads and reworking them and then reflowing them.

He eventually went with SPM heads instead of creating his own, but he has a lot of thoughts on working over volvo heads