Hi guys,

I have to let new valve seats cut by a machine shop. This shouldn't be a problem on the exhaust valve seats because as Vader has pointed out, they are induction hardened deep enough to survive this procedure without having to re-harden them or have inserts installed.
But the guy at the machine shop is driving me crazy by insisting on, that the intake valve seats have to be replaced with an insert because they are (or should be in case they are not yet) hardened, too.
My information on valve seats is as follows:
1. We have hardened exhaust valve seats to be able to let our enginges run on unleaded fuel.
2. To my knowing the intake valve seats are just cut into the cast iron and no hardened seats or inserts are installed/needed.

The exhaust valve seats on my heads have a more shiny, nearly "chrome-like" finish than the intake valve seats.
So, to me, the intake seats don't SEEM to be hardened and there is definitely no insert installed.
I would just like to know for sure which information is correct and what to do. Letting the machine shop install inserts on the intake seats or not?
Heads are #187 castings.

Thanks in advance,

Andreas

 

They shouldn't need inserts.

Don't waste money working on those heads. They are among the worst-performing heads that exist. If you're going to spend money on machine work, apply it to better castings.

 

As stated, the intakes shouldn't need seat inserts.

What are you doing with the heads, anyway? Aren't those TBI heads (a.k.a., swirl port)?

 

Vader,

they go back onto my engine.

 

RB,

thanks for your reply.

That's what I think. And the stock intake seats aren't hardened, are they?

I know, RB. But look where I live. It is virtually impossible to get a set of used and better heads over here, they are rare occasions and I don't trust ebay. New heads are too expensive and my car is a daily driver, so they fulfill requirements.

 

If you perform some serious bowl portting, raise the roof in the intake runners, shorten the short side radii on both sides of the head, cut the valve guide protrusion to nearly nothing and clean the port runner sides until they are dangerously thin, you should get some flow improvement.

I can imagine that project would be like some of us trying to find performance Opel parts, if there is such a thing.

 

Vader,

just in case this could be of interest:

I already thought about upgrading my heads and shoot for set of the lowest priced heads I could find.
A set of bare WP Torquers 305 is EURO 900,- over here. Add springs, retainers and valves and you will easily end up somewhere in the EUR 1.500,- range (+/- 100,-) plus s+h.
Multiply by 1.32 and you have a buying power equivalent of USD 1.930,- just for a set of heads (+ gaskets, + labour,+XXXX?)

To me, this seems a little too much money for a set of heads for a daily driven LO3

Thanks for your advice. I already thought about that and I will see what I can do.

Lol! That's a good analogy! Yes, there are Opel (and BMW, Audi, Daimler, Renault, Fiat and whatever european car brand you want) parts en masse over here and you'll find them in as large a variety for the above car brands as you do find them for american car brands in the US.

 

Vader,

you are much faster by answering/editing your post as I can react to it.

Yes, these heads are swirl ports.

 

I have a set of Iron L98 heads, they are bare, and will need new valve stem guides, but otherwise they are in okay shape. You can have them if you pay shipping (I work for FedEx, so you will get the 75% discount) Shipping and handling will probably be around $125.

 

Wizard,

thank you very much for your offer, I really appreciate your kindliness. But my heads are already "in the works". The only problem was the machine shop guy trying to convince me I need hardened intake valve seats and myself, not wanting to believe that because a new seat cut is only EUR 12,- per valve and an insert is EUR 50,- per valve.

 

I'd opt for having the seats cut and installing new SS valves. I'd also get a die grinder and start hewing out the heads.

You might actually want to port up the heads before the valve seats are cut, just in case there is an Oops! or two while porting. When the heads are machined for valves, you can also have the bowls ported (since the mill setup is essentially the same). That can save you a lot of manual porting work in the bowl area. When you're all finished you might have something - at least it should be some improvement. I've ported a set of '993 heads, which are also pretty crappy castings, and got some reasonably good port volumes and runner cross sections as a result. The big detriment is the angle of flow at the valve bowl ends, since the castings are fairly flat and don't aim the charge at the back of the valve very well. You can raise the roof of the intake runner to help some, but can only do so much to a poor casting.

 

Hi man! Could you get me that discount too?
I'm trying to get a front nose shipped over here, and so far the quotes I've got on shipping for it is $500 on which I have to pay an additional 25% tax.

Are there any way one could qualify for some dicounts of any kind?

 

Vader,

I already have Manley SS Street Flow valves. They are 1,94" intake and 1.50" exhaust valves since Manley doesn't seem to make 1,84" valves at all. The price tag here was nearly the same as for the stock GM valves.
I don't have a garage and a die grinder so I will do that work at home in my home office and I will use my dremel (I know, this is not the preferred tool to do this job). This will definitely take its time but I became more patient in my late thirties than I was a decade ago and it will save me some money.
This way I will probably (and hopefully) end up in the EUR 600,- to 700,- cost range, maybe a little more (labour, new parts and gaskets included).

The head work is already in progress. Concerning the bowl work and the crappy casting:

I see it as some kind of a challenge to make these heads flow a little better and to me it is an opportunity to learn and do something new I could/would never adept otherwise without spending too much. I have read DynoDon's posts about porting the #193 castings some time ago and was fascinated by this idea from the beginning. This reading, and of course the fact that I will save some money, made me decide to do what I do now. I know, that one can not turn these castings magically into high performance heads but this is not necessary. To me, it would be sufficient if I could make them flow better betwen 4.000 and 5.000 RPM (maybe a little higher) and have the engine rev limited by the camshaft rather than by the breathing ability of the heads.

I will be careful when working on the heads and hope for the best. That's definitely not the route to take (My mistake, I should have done it the way you are suggesting) but things are as they are right now and cannot be reversed and so I have to make the best out of it.
The valves alone should give me some gains in the low lift range. The only thing disturbing me with those heads is the lack of power above 4.000 RPM. My goal is, to make them flow a little better above 4.000 RPM so that one can feel the engine is still "alive" in that RPM range.

To me, the head design (the cast forced swirl) is the biggest challenge. I strongly believe that it is a totally different story working on these heads compared to conventional castings. IMHO one of the weakest points concerning flow could be the valve guide boss and that part of the ramp that extends into the intake (when you look into the intake from the intake manifold side). It is where the head seems to have the lowest cross sectional area in the intake.
I wouldn't dare to grind down the guide boss completely but I believe, if one does "thin it out" a bit, by reducing the guide bosses outer diameter closer to that one of the valve stem diameter, one could gain two or three square centimeters of cross sectional area (that's just a guess). That could help flow without hurting port velocity too much.

This is what I mean by saying "a completely different story". The flow is not directed "vertically" towards the valve head but is rather "horizontally" swirling into the chamber (it seems to "screw" itself into the cylinder), directed by bowl design and the ramp.
As an advantage, you have a better combustion due to the swirling effect which should mean a little more power compared to a non-swirled mixture.
IMO, if one fights that by trying to alter the intake mixture path into a more traditional one, one would probably rather loose power instead of gaining some.
If one instead does not fight this but helps the mixture to swirl ("screw") in easier by

1. using backcut valves (or the Manley Street Flow ones)
2. increasing the cross sectional area slightly
3. grinding down obstructions (the casting marks, the intake runner wall next to the pushrod as much as possible without making it "paper thin", open up the throat under the intake valve)

one should, IMO, end up with a better flowing swirl port design that still delivers the advantages of the design (torque, better mileage) without hurting higher rev breathing capability too much if my assumptions are correct.

I have a drawing attached, which I hope isn't too big, that shows what I am talking about. It shows a look down into the bowl from the valve side. The black dot is the valve guide, the grey ring around it is the guide boss and the white ring around those two shows the ramp. The two arrows to the right represent the current intake runner width when entering the bowl and the dotted arrow on the left shows the maximum gain of width one can achieve by grinding down the guide boss completely.

Anyway, whatever the results will be, I will have much fun doing this "experimental" stuff and it won't cost me a fortune.

 

Message sent and kicked back:

Hi Andreas:

The first thing I can tell you is be careful. If no one has told you,
these heads are very thin castings. I had the luxury of having a junk
head to play with and therefore found how much area I had to play with.
That being said I have to tell you a year later one cracked.

So don't try to get to thin in any area. Just thin the guide area and
the short side radius and clean up the bowls. That should help all that
there is available. Remember I did '193's I have no experience with
'187's.
Hope that helps,
Don>>>

PS head picture attached
blackbird92@tiscali.d

 

If you're cautious, you CAN cut the bowls and remove the "swirlie humps" from the pockets.

 

Thanks for your input guys!