Head porting info required.

CastleMGBV8 · Post by **CastleMGBV8** » Sun Dec 21, 2008 11:45 am

Tom,

I would have thought best done on proper equipment like a Serdi seat cutting machine, if a three angle valve job is required the Serdi machine can do it as a single operation.

Kevin.

topcatcustom · Post by **topcatcustom** » Sun Dec 21, 2008 9:19 pm

Have been told that 3 angle cuts are less beneficial on blown applications... If the standard ex. valves are 1.375" and the next size up is 1.4" then they are only .025" bigger- about 0.6mm??- Is it really worth it?! If so, and dont go for 3 angle then maybe a hand tool would be able to do it ok? Dont want to spend much on this pair of heads- rather save up for some proper stg 3's once its all running...

chodjinn · Post by **chodjinn** » Mon Dec 22, 2008 10:09 am

topcatproduction wrote:Have been told that 3 angle cuts are less beneficial on blown applications... If the standard ex. valves are 1.375" and the next size up is 1.4" then they are only .025" bigger- about 0.6mm??- Is it really worth it?! If so, and dont go for 3 angle then maybe a hand tool would be able to do it ok? Dont want to spend much on this pair of heads- rather save up for some proper stg 3's once its all running...

That's what I have heard. I'm planning on fitting 1.5" exhaust valves when i get round to it.

CastleMGBV8 · Post by **CastleMGBV8** » Mon Dec 22, 2008 11:41 am

You need larger seat inserts to take a 1.5" Ex. valve.

Kevin.

topcatcustom · Post by **topcatcustom** » Sun Dec 28, 2008 7:31 pm

I'd say this porting lark is- tedious

First one or two are ok..... Am taking quite a lot of material out espec in the exhaust ports so may get it in the mill and see if its quicker- the exhaust ports are coming out 25x35mm which is quite a lot for a little carbide cutter!!!

spend · Post by **spend** » Wed Dec 31, 2008 1:29 pm

Any one know of good sources for 1.5" ex valves, I'm looking for some at the moment. Only heard of JE doing them?

CastleMGBV8 · Post by **CastleMGBV8** » Wed Dec 31, 2008 2:21 pm

spend wrote:Any one know of good sources for 1.5" ex valves, I'm looking for some at the moment. Only heard of JE doing them?

Dave,

Do you really need a 1.5" Ex. valve, I don't think you will see much benefit unless the exhaust port and especially the bowl area has had extensive work, you will also need to replace the valve seat inserts as the largest valve the standard seat will take is 1.4"

Kevin

spend · Post by **spend** » Wed Dec 31, 2008 2:48 pm

CastleMGBV8 wrote:
spend wrote:Any one know of good sources for 1.5" ex valves, I'm looking for some at the moment. Only heard of JE doing them?
Dave,

Do you really need a 1.5" Ex. valve, I don't think you will see much benefit unless the exhaust port and especially the bowl area has had extensive work, you will also need to replace the valve seat inserts as the largest valve the standard seat will take is 1.4"

Kevin

They are bigger than 1.4" already? and yes I am sure I want 1.5"

, well aware of seat requirements (the existing ones might just cope) and the scope of guide replacement for thinner stems... I do have one set but they are earmarked for another project

So could anyone refer me to a good supply please, I haven't got 2 pennies to rub together

?

kiwicar · Post by **kiwicar** » Wed Dec 31, 2008 3:11 pm

Try Ebay using "buick exhaust valves" I found
http://cgi.ebay.com/ebaymotors/BUICK-LE ... ccessories
And
http://cgi.ebay.com/ebaymotors/1968-197 ... ccessories
you will need to decide what length you need, look for 318 v6 valves if you cant find 215s in the diamiter you want, avoid the straight 8 and 364 straight 6s. There are always chevy or ford valves in more sizes than you can shake the proverbial stick at.
Mike

CastleMGBV8 · Post by **CastleMGBV8** » Wed Dec 31, 2008 5:06 pm

spend wrote:
CastleMGBV8 wrote:
spend wrote:Any one know of good sources for 1.5" ex valves, I'm looking for some at the moment. Only heard of JE doing them?
Dave,

Do you really need a 1.5" Ex. valve, I don't think you will see much benefit unless the exhaust port and especially the bowl area has had extensive work, you will also need to replace the valve seat inserts as the largest valve the standard seat will take is 1.4"

Kevin
They are bigger than 1.4" already? and yes I am sure I want 1.5" , well aware of seat requirements (the existing ones might just cope) and the scope of guide replacement for thinner stems... I do have one set but they are earmarked for another project

So could anyone refer me to a good supply please, I haven't got 2 pennies to rub together ?

What engine heads are they going into?

Kevin.

spend · Post by **spend** » Wed Dec 31, 2008 5:23 pm

CastleMGBV8 wrote:What engine heads are they going into?

Kevin.

A set of quite nice TVR BV's . (compared to other UBV heads from TVR - the workmanship does vary and these are pearls iMHO)

spend · Post by **spend** » Wed Dec 31, 2008 5:31 pm

kiwicar wrote:Try Ebay using "buick exhaust valves" I found
http://cgi.ebay.com/ebaymotors/BUICK-LE ... ccessories
And
http://cgi.ebay.com/ebaymotors/1968-197 ... ccessories
you will need to decide what length you need, look for 318 v6 valves if you cant find 215s in the diamiter you want, avoid the straight 8 and 364 straight 6s. There are always chevy or ford valves in more sizes than you can shake the proverbial stick at.
Mike

Thanks for that, do you know if any of those are wasted Mike? Pics look like they aren't or are they just lib snaps? IIRC they are also some Merc candidates as well as Fords (but they require different size guides?) Wouldn't mind thinner stems in one way, but wonder if they will still be OK with the roller rockers?

kiwicar · Post by **kiwicar** » Wed Dec 31, 2008 6:30 pm

Hi
if you are looking for 1.5" head valves then really you don't need to bother about original application (unless it is sodium filled or a funny tulip profile) GM and ford in the states use the same suppliers, if it is a 5/16 stem 1.5" head 4.9 inch long exhaust valve in a Buick, SBC of ford 302 it is probably the same valve sourcedfrom any one of seven or eight suppliers the only reason I said to avoid the straight 8 or straight 6 was that when these were designed there were some funny ideas about what was needed in an exhaust valve design.
This is the reason valves are so cheep in the states the manufacturers make them in batches that would keep a european engine builder going for years, they can supply them to the big 3 and have them fitted to loads of different engines.
Decide what you want (thinner stem than standard buick 215/rover ) ?then decide metric or imperial (I would go imperial) then sort out what length you need, hunt on Ebay until you find a match. My chevy valves are 2.08 head inlets 1.76 exhausts, swirl pollished light weight with waisted stem stainless and 1/4 inch longer than standard on a 3/8 stem, they are pretty non standard on an SBC factory head but will be standard fit on some US engine, hence they cost me less than £120 delivered for all 16.
I pointed you at the buick 318 V6 because I know this engine is developed from the 215 v8 and stands a good chance of having the same stem diamiter and stem length as the 215.
Really the first place to look is on comp cams, manley or isky websites to see what they do Manley make valves for the big 3 plus "smaller" batches of performance valves (often just different machining on a common blank) Isky make performance valves in all sorts of sizes so they could be worth contacting to see if the do the valves you want. Comp cams stock a wide range of different valves from all over so again email and ask if they do what you want.
On Ebay you could contact Mad dog racing and ask them if they do the valve you want, I only surgest them as I have dealt with them before and they are helpfull (and pretty cheep as they do big turnover.
Most photos on Ebay are library so if you want a particular feature like waisted stem and it does not say it has it, ask, the US suppliers are hurting at the moment, one I have used a couple of times and was very helpfull supplying difficult to get bits went under a week before christmas, they are very keen on your business and will help all they can to get business.
Good luck.
Mike
PS 1.55" head looks like a standard head size for a chevy vortec truck head if the stem length (I think it is 4.905) matches what you want then they could ne very cheep!! you just have to spin them up in a lathe and take a 25 thou cut off each one. 1.46 is also a chevy valve size.......

topcatcustom · Post by **topcatcustom** » Sat Jan 10, 2009 9:22 pm

Hey Perry how's the porting going?!

I only have the exhausts to do on 1 head then my pair is done! Quite pleased with how it has gone although I know I could do more- but the car is going to be a handful without ported heads so I have nothing to lose by giving my porting skills a shot!

I am more interested in the exhausts as the supercharger will blow plenty of gas in through std ports, but getting it out is more of an issue! Still- it doesn't hurt to give the inlets some attention at the same time though eh?!!!

I have opened up the runners to gasket size (a lot!) on the inlets and exhausts all the way through, and taken a bit out from around the guides but I still don't have a press to remove them to port around them fully so that can be an upgrade in the future at some point. I also bulleted the ex. guides a little using a pointy carbide burr bit, smoothed the ex. ports with 150grit sanding rolls in a dremel but left the inlets rough to help with atomisation of fuel.

Finally I have de-shrouded the valves by champhering the head material around the valves (approx 100degs each), and was suprised at just how much I could open up the exhaust ports behind the valves! There is so much meat there, I think the internal diameter is about 28mm std which I have taken out to just shy of 30mm, and that is not cutting it too fine either! Of course all the ridges etc have been smoothed away too.

I am leaving the std valves in for now as I want to get the whole thing built and running before I keep pumping more money into it. Will post some pics when I finish and give them a clean!

TC

mgbv8 · Post by **mgbv8** » Sun Jan 11, 2009 6:44 pm

I've done nowt so far mate!!
All my weekends have been taken up with work, getting a V8 into another MGB and titting around getting my 21 year old MR2 on the road.

I'm building my new heads to be ready for the end of the season this year as I've shed loads of stuff to try out before I pull the engine again.

Will be interested to see how your first attempt goes though.

Perry