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Old 12-02-2019, 02:19 PM   #1
Avtovaz
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Default 530 valve seats for porting

just looking at my 530 head today, its got the biggest valves in the standard seats, is taht 44/38? cant remember but, the seats havnt had any material removed from them at all, it looks to me like that is restricting the head flow, can you take material from here?

thanks
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Old 12-02-2019, 02:33 PM   #2
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The inside diameter of the seats needs to be opened up. I open them up to 86-88% of the valve diameter. Open the intake seat to approximately 38-38.5mm, and the exhaust to approximately 32.7-33.5
The port area under the seat will also need to be enlarged as well.
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Old 12-02-2019, 02:38 PM   #3
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thankyou that is exactly what i needed to know!
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Old 12-02-2019, 05:31 PM   #4
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one moer question i have a 530 that has been worked and then i also have a stock 531, i can see the 531 on the inlet side has a much better flow. Its the same height port size but the width on one side is much better.

ive only seen pics of the 530 with just enlarged port. is that a real restriction? what can be done in this area to open it up?

thanks
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Old 12-02-2019, 07:09 PM   #5
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The real restriction on both heads is the exhaust side. It is undersized, and the short turn radius (sharp corner) needs to be smoothed over.
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Old 12-03-2019, 09:48 AM   #6
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Quote:
Originally Posted by culberro View Post
The real restriction on both heads is the exhaust side. It is undersized, and the short turn radius (sharp corner) needs to be smoothed over.
Back when I was drag racing and had a friend that ported heads. He showed me how most people wrench the short side radius. They would try and shorted it which would cause turbulence when mix would hit the valve. I wonder if that rule still applies to these heads?
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Old 12-03-2019, 12:40 PM   #7
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The Volvo 8v exhaust port is designed very similarly to a 90deg brass fitting. It’s basically two holes drilled 90deg from each other, with a sharp inside corner. Widening the port floor (not lowering it) and creating a short side radius is where most of the gains are. There’s just not that much material to remove on these heads in other places.

On some decent heads, removing too much, or the wrong shape, on the short side can be a detriment. The Volvo 8v needs the entire exhaust port moved up 10-15mm just to match a poor flowing iron v8 Head.
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Old 12-03-2019, 02:11 PM   #8
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so can it be ported to look more like a 531, or is that not a good idea as its not the heron head?


how wide can you go before hitting anything or making the flow worse?

thanks!!
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Old 12-03-2019, 02:40 PM   #9
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Quote:
Originally Posted by Avtovaz View Post
so can it be ported to look more like a 531, or is that not a good idea as its not the heron head?


how wide can you go before hitting anything or making the flow worse?

thanks!!
Are you talking about porting the intake, exhaust, or both to look like a 531 head?

When I get a flow bench, I'll let you know

I just follow what Erland Cox talks about with the 8v heads. It's not radical, it works well, and it's simple.
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Old 12-03-2019, 03:48 PM   #10
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isnt the exhaust the same anyway?

where can i find this info from Erland Cox?!
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Old 12-03-2019, 04:09 PM   #11
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Originally Posted by Avtovaz View Post
isnt the exhaust the same anyway?

where can i find this info from Erland Cox?!
The exhaust it very similar between the 530 and 531. I don't think there is enough material in the port walls to carve a 530 into a 531 style head. But, a ported 530 and a ported 531 have very similar flow capacities.

Erland's site seems to be down, but it can still be accessed through the wayback machine: https://web.archive.org/web/20180829...foretaget.html
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Old 12-06-2019, 07:22 AM   #12
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For some extra inspiration, I just uploaded the folder I collected when doing my own porting and valve deshrouding for inspiration, maybe some of it helps I mostly rounded the harsh angles mentioned, and blended the valveseats to the ports, to get rid of the edges.

Volvo 530/531 porting inspiration/own work


I'd also recommend having a look at this video by JafroMobile, a very good tutorial with useful tips, the whole channel is worth a look to learn stuff for engine building


And for part 2


Good luck!
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Old 12-07-2019, 01:36 AM   #13
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Quote:
Originally Posted by culberro View Post
The Volvo 8v exhaust port is designed very similarly to a 90deg brass fitting. It’s basically two holes drilled 90deg from each other, with a sharp inside corner. Widening the port floor (not lowering it) and creating a short side radius is where most of the gains are. There’s just not that much material to remove on these heads in other places.

On some decent heads, removing too much, or the wrong shape, on the short side can be a detriment. The Volvo 8v needs the entire exhaust port moved up 10-15mm just to match a poor flowing iron v8 Head.
can the valve guide boss be completely eliminated or do you need to keep it for the guide support? Does the head respond to good 3 angle valve job. Would be disheartening to port a head and make it worse or unreliable.
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Old 12-07-2019, 08:05 AM   #14
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Quote:
Originally Posted by culberro View Post
The inside diameter of the seats needs to be opened up. I open them up to 86-88% of the valve diameter. Open the intake seat to approximately 38-38.5mm, and the exhaust to approximately 32.7-33.5
The port area under the seat will also need to be enlarged as well.
I'm in the process of doing some work on a 1990 530 head before taking it to a m/s to have 38/46 valves installed.
I've been looking for info like this for when I take the head in. However I did the math & got 88% of 46mm rounded up to 40.5mm
Also I've just measured the head (to get an idea of how much needs to come off) & the diameter of the inlet seat, just under where the valve sits is about 40.5mm. It tapers in to about 38mm at the base of the seat. Last measurement could be a little off but there is a definate taper. The actual port where the seat sits is a little larger than the seat (felt with finger).
In opening up the seats would you increase the diameter by 2mm to match the increase in valve size? Is the taper important? I would think reaming/boring it to resize it would leave it parallel.
Tim
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Old 12-07-2019, 04:24 PM   #15
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Quote:
Originally Posted by 90volvo View Post
can the valve guide boss be completely eliminated or do you need to keep it for the guide support? Does the head respond to good 3 angle valve job. Would be disheartening to port a head and make it worse or unreliable.
A three angle valve job is stock so you need to do this at least to stock. My shop brought the area under the seats to match the same size as the seat where it meets that area. The taper is very important so you don't creat turbulence. Even with stock valve sizes my shop was able to get about a 20% increase in flow.

Here is a thread where there is big discussion on what to do. Even the famous/infamous? Pacman added to the thread. Sorry my picitures are long gone. https://forums.turbobricks.com/showt...ghlight=405%2A
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Last edited by dl242gt; 12-07-2019 at 04:32 PM.. Reason: add link and comment
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Old Yesterday, 05:28 PM   #16
culberro
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Quote:
Originally Posted by 90volvo View Post
can the valve guide boss be completely eliminated or do you need to keep it for the guide support? Does the head respond to good 3 angle valve job. Would be disheartening to port a head and make it worse or unreliable.
The exhaust guide can easily be shortened and ground to match the port, it is very well supported. The intake guide can be shortened up too, but it is not supported as well. I don't think this creates a longevity issue. I have done this on my daily driver 240 and an old race head without any issues. The stock guides are already significantly longer than most heads.

The stock valve seat does not have a 30deg top cut in the stock heads I have worked on, it is really a 1 or 2-angle valve seat from the factory.
The stock valves and seat geometry make it difficult to get a true 3-angle valve seat, as the valves sit protruding slightly into the chamber. This can be done, but it "sinks" the valve into the head a bit, and the valves must be shortened or thin valve shims used.

Quote:
Originally Posted by K9 240 View Post
I'm in the process of doing some work on a 1990 530 head before taking it to a m/s to have 38/46 valves installed.
I've been looking for info like this for when I take the head in. However I did the math & got 88% of 46mm rounded up to 40.5mm
Also I've just measured the head (to get an idea of how much needs to come off) & the diameter of the inlet seat, just under where the valve sits is about 40.5mm. It tapers in to about 38mm at the base of the seat. Last measurement could be a little off but there is a definate taper. The actual port where the seat sits is a little larger than the seat (felt with finger).
In opening up the seats would you increase the diameter by 2mm to match the increase in valve size? Is the taper important? I would think reaming/boring it to resize it would leave it parallel.
Tim
Tim, the measurements I posted above were using the valve diameters listed by the Avtovaz, so that's where the discrepancy is
The 85-88% measurement is for the ID of the valve seat insert, and I match this to the aluminum ports in the head. From there, I will taper out at ~70-80deg to the 60deg that I have cut into the seat.
When I do larger valve heads, I bore the seat ID to 85-88% of the valve OD, and then go from there. This is the sweet spot for most engines. I might go bigger on the exhaust, and smaller on the intake, as the exhaust is the true restriction on these heads.

Quote:
Originally Posted by dl242gt View Post
A three angle valve job is stock so you need to do this at least to stock. My shop brought the area under the seats to match the same size as the seat where it meets that area. The taper is very important so you don't creat turbulence. Even with stock valve sizes my shop was able to get about a 20% increase in flow.

Here is a thread where there is big discussion on what to do. Even the famous/infamous? Pacman added to the thread. Sorry my picitures are long gone. https://forums.turbobricks.com/showt...ghlight=405%2A
See above for what I've seen for stock valve angles. Even on heads that have been rebuilt, I've seen them done with a single angle seat!
I'm not surprised that the shop was able to increase flow 20%, these heads are pretty bad from the factory
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