SCAT'S Split Ports With New Rocker Box Design

[Wally]

This is the pic you meant I think Richard? Old design, but still..:


All the pics I made back then of this engine in the convertible:








and another engine with them:





They still are a very good design, just the cooling is a worry..

Frallan seems to have had T4 ready manifolds?
Were T4 split port manifolds from Scat ever a 'bolt-on' item?

[Frallan]

Water jacketed like my engine from mid 80´s.
Worked OK but for sure had its own probelms which I will not do again.




As for bolts holding down the rocker boxes, why do you get stuck on that?
Count the amount of bolts and compare to T1 and TIV original.

- T1 has two bolts holding the rockers of 4 valves.
- TIV has two bolts holding the rockers for two valves
- Scat has three (or four now) per two valves.

Show me any situation were that has been a problem?
I know Jake had some input but never showed me any documented problems with it.
It is a pretty stable construction and it got just a bit better with the new design.

[Type 4 Unleashed]

Richard, there's this thing called email... I asked them.
The 50x40s have the guides installed, this implies some level of porting.

Didn't realize the T4 manifolds were "custom", For that price, I'd bolt TBs to the ports.

New style, we ship from the factory.

Joe

-----Original Message-----
....
To: evwparts@evwparts.com
Subject: SCAT split port T4 head kit 25119-1

I'd like to confirm price, and are these available?

Also, are these the old style (as pictured, with the rocker shaft going
through a hole) or the new revised style (that doesn't leak)?

Thank you.

...

It's the same price for the 94mm bore heads and the 103mm bore heads. The guides are not instralled in the 94mm bore heads untill their ported and no price for the porting ? SCAT does not give stuff away for free, the add is vague and so is their response to your email.

[Type 4 Unleashed]

This is the pic you meant I think Richard? Old design, but still..:

All the pics I made back then of this engine in the convertible:





They still are a very good design, just the cooling is a worry..

Frallan seems to have had T4 ready manifolds?
Were T4 split port manifolds from Scat ever a 'bolt-on' item?

There is one guy here who runs a 2366cc with the Split-Ports in a convertible. The engine was professionally build by a shop and had a 11-blade fan cooling, still after some highway driving a valve seat dropped...
I cannot think of any other reason then that the engine got too hot due to insufficient cooling.


Well I Can ...

Nice Pictures Walter

The guy with the convertable the underside pic was the one you posted before, but as to dropping a seat, I don't think it would of happened. I don't know how professional the shop was, but they apparently knew nothing about aircooled Type lV's, casue if they would of known anything about them, they would of know that they needed some type of reflector tins to go underneath to do what Walter ? You made your own for your motor. And it's a well know fact to what happens to stock heads that don't get the reflector tins. Walter did you ever notice the missing cooling tins ?... ... I don't remember if I did before or not, but this time when you mentioned the drop seat, it was clear as to why.

As for the manifolds, the heads were designed for the Type 1, as were the manifolds for the Type 1 cyl spacing & stud pattern, but later they just drilled them for the Type lV stud spacing, but never made manifolds for the Type lV, or relocated the holes for the 2 cyl's that have the offset push rod tubes.


And I would even wonder if anyone else who ran the Split Ports bothered to put some type of cooling tins on the cyl's and heads ?

[Wally]

Good catch Richard
That might have helped Weird I didn't even notice that even then.. I think the builder thought with the porsche cooling and the 103 bore (small passage) that would not be neccesary or would hinder flow. On my own current engine I have not installed the deflector tins on the cylinders either (!) as a test I did with compressed air showed the narrow passage between the alu 103 bore cylinder DID deflect the air flow around the cylinders by itself. Try it yourself, its rather weird to notice this. I did however install (modded) deflector tins under the heads! as the center hole in the head does need it and it helps there.
Now that I think of it, I heard later the owner himself also made some kind of supercharger on the engine. The engine only ran with 1:8 or so CR, so he wanted more powerrrr. It is also possible tuning may have had s/th to do with the seat dropping as well, who knows..
It is strange these heads haven't caught on in the type 1 world more. After all, they seem to flow very well. Are there flow numbers?

Nice supercharger Frallan! Amazing what you have all made and experimented with through the years!
How did the crank nose bearing (no.4) held up on the one-directional load from the charger-drive?

[Frallan]

I never had a thought about TIV bolt pattern or TIV manifolds.
Placed the order and I got what I wanted.
I even asked if they could get someone to do match porting and open up my chambers to my desired CC.
Then I replaced the steel seats for JM7 bronze and made my own vavleguides that supported the inner spring.
I have never liked steel seat and I have never seen a seat out of JM7 installed right, loosen. Not even at very tough environments.

As for the pushrodtubes, used T1 and a some silicone goo.
I rememeber I had to do some work on the heads sealing surface to get the right angle for the tubes.
It was done by hand and a "Swedish mora kniv". I guess like a small hunters knife.

T3 under cylinder tins were used and they can be noted as ugly bad painted black one in one picture.

As an afterthought I really did like the heads. One thing I did not like and I reflected upon it now.
I could not do very much about rocker geometri.
Look at the lashcap and you will see what I mean.

[Frallan]

Quote:
Nice supercharger Frallan! Amazing what you have all made and experimented with through the years!
How did the crank nose bearing (no.4) held up on the one-directional load from the charger-drive?[/quote]


Well it has held very well.
Same crank since 1977.
I.e. Okrasa 82 mm.
I had it magnafuxed latest little bit over a year ago and no problem at all.

The same crank has seen both the WADE (many street miles in the late 70´s and up to mid 80´s) and the then the Autorotor for limited time in the 90´s before the engine came back in NA mode.
I think it is mostly about being 100% sure you keep everything in good balance as being the main and most important parameter.
Sure, if I do it again, as I am contemplating of using the same Autorotor on my 911 OHC engine for the dragster, it will see an outboard supported drive double bearing.
So almost all forces on the crank will be axial and none radial at all.

[Type 4 Unleashed]

As an afterthought I really did like the heads. One thing I did not like and I reflected upon it now.
I could not do very much about rocker geometri.
Look at the lashcap and you will see what I mean.

Before in the old design when the shafts went thru the rocker boxes, you just shimmed the box to set Geo, now I think you can shim the shafts now in the new design to set Geo.

[Type 4 Unleashed]

Good catch Richard
That might have helped Weird I didn't even notice that even then.. I think the builder thought with the porsche cooling and the 103 bore (small passage) that would not be neccesary or would hinder flow. On my own current engine I have not installed the deflector tins on the cylinders either (!) as a test I did with compressed air showed the narrow passage between the alu 103 bore cylinder DID deflect the air flow around the cylinders by itself. Try it yourself, its rather weird to notice this. I did however install (modded) deflector tins under the heads! as the center hole in the head does need it and it helps there.
Now that I think of it, I heard later the owner himself also made some kind of supercharger on the engine. The engine only ran with 1:8 or so CR, so he wanted more powerrrr. It is also possible tuning may have had s/th to do with the seat dropping as well, who knows..
It is strange these heads haven't caught on in the type 1 world more. After all, they seem to flow very well. Are there flow numbers?

Nice supercharger Frallan! Amazing what you have all made and experimented with through the years!
How did the crank nose bearing (no.4) held up on the one-directional load from the charger-drive?

Maybe you think they have enough cooling, and thats your call, but not all the air is being circulated around the cyl's and reflectors would help. I was at a Porshce shop some time ago, and they were re-building a turbo motor, and I saw the factory Aluminum cyl reflectors, it was one piece and covered all three cyl's, and each cyl had a place that a Knock sensor was mounted, so if that cyl had detonation, a signal was sent back to the computer and the timming was backed off on that cyl, and after seeing the reflectors one of the cyl's could be cut off and it could then be used on a two cyl setup...

As for the Split Ports, I believe there are flow #'s, will they let me have a copy, I will ask and see what happens.

As for their cooling I agree they could be much better, they have some pretty thick fins, But I have some ideas and one day if I ever get a set to play with I will play with them...

The price I mentioned earlier was for a set of heads completed, and saw some of the work being done, and in my price break down I didn't include Springs retainers or keepers, but in the heads I am talking about the CB VW650 ($99.95) springs were used due to the intended valve lift being .600" and don't remember what retainers were used.

[Frallan]

As an afterthought I really did like the heads. One thing I did not like and I reflected upon it now.
I could not do very much about rocker geometri.
Look at the lashcap and you will see what I mean.

Before in the old design when the shafts went thru the rocker boxes, you just shimmed the box to set Geo, now I think you can shim the shafts now in the new design to set Geo.

Yes you are right but you need a nice full size shim.
New design is really a big lift and I had my own ideas of re-doing them in this way.
My background is that I cut up a set of angle flow heads just prior to buying these and when I mean cut up, just that.
I started doing my own angle flow split heads and I had a scetch which is very similar to this solution which Scat has today.
The history of these angle flow heads is funny, now a days. I gave them away to a friend after buying the Scat heads, he has welded them back togehter as one piece heads again.....but never finished them to a running set, yet.

[Wally]

Maybe you think they have enough cooling, and thats your call, but not all the air is being circulated around the cyl's and reflectors would help.

I tested the airflow. What did you do?
Oh this?:

I was at a Porshce shop some time ago, and they were re-building a turbo motor, and I saw the factory Aluminum cyl reflectors, it was one piece and covered all three cyl's, and each cyl had a place that a Knock sensor was mounted, so if that cyl had detonation, a signal was sent back to the computer and the timming was backed off on that cyl, and after seeing the reflectors one of the cyl's could be cut off and it could then be used on a two cyl setup...

You cannot compare a 103mm thick Oettinger alu cylinder to a factory 964/993 (dunno what you saw) cylinder set wrt airflow..

Pls stay a bit more open minded Richard! If I run without the T1 deflector plates under MY engine, be sure there is ample reason to do so

[Type 4 Unleashed]

Maybe you think they have enough cooling, and thats your call, but not all the air is being circulated around the cyl's and reflectors would help.

I tested the airflow. What did you do?
Oh this?:

I was at a Porshce shop some time ago, and they were re-building a turbo motor, and I saw the factory Aluminum cyl reflectors, it was one piece and covered all three cyl's, and each cyl had a place that a Knock sensor was mounted, so if that cyl had detonation, a signal was sent back to the computer and the timming was backed off on that cyl, and after seeing the reflectors one of the cyl's could be cut off and it could then be used on a two cyl setup...

You cannot compare a 103mm thick Oettinger alu cylinder to a factory 964/993 (dunno what you saw) cylinder set wrt airflow..

Pls stay a bit more open minded Richard! If I run without the T1 deflector plates under MY engine, be sure there is ample reason to do so

as a test I did with compressed air showed the narrow passage between the alu 103 bore cylinder DID deflect the air flow around the cylinders by itself. Try it yourself, its rather weird to notice this. I did however install (modded) deflector tins under the heads! as the center hole in the head does need it and it helps there.

1st off I don't have any Oettingers, and if your happy with the comparison of an air nozzle shooting compressed ait at what, 80 to 150 psi between the cyl's compared to the air flow that would come from the Reichert fan, then thats your choice. But I at least know no matter how much air is passed between the cyl's unless it's deflected it's not going to make a 90 deg turn to cool the bottom of the cyl's.

I can compare anything I want, as you did with your compressed air test. The deflectors had my intrests due to the easy mounting of knock sensors. Anyways I would use Type lV deflectors before I would use Type 1's, but thats my choice.

I have an open mind, especially if you can change the Laws of Physics...

Walter you remember this Topic ?

DTM and "under cylinder tins", are they fully needed ?

[Piledriver]

It's the same price for the 94mm bore heads and the 103mm bore heads. The guides are not instralled in the 94mm bore heads untill their ported and no price for the porting ? SCAT does not give stuff away for free, the add is vague and so is their response to your email.

Take it up with the vendor, Richard, I have never dealt with them.
If I had a spare ~$2K I'd be tempted to find out...
I bet they would cool reasonably well with Nickies or the Mahle alloy jugs helping.

The point was they are apparently available and are a viable alternative to the silly high $$$ and flakey availability of EP or Reichert heads. (I think that was the main point of the whole thread)

It would be nice if they had proper T4 layout rocker boxes to straighten out the pushrods, but that could ~certainly be done due to having seperate rocker boxes... If I had a set I'd probably be tempted to try it with the 1.48:1 T4 Autocraft roller rocker assys, might be woth some time at the Bridgeport.

OTOH Frallan and others have run them with the pushrods as they are, so it might not be worth the effort.

[Wally]

Walter you remember this Topic ?

DTM and "under cylinder tins", are they fully needed ?

What about it? I used modded type 4 tins under 964 cylinders? Yes, you should, as those square jugs leave BIG holes between them when used on a type 4! Duh!
Lemme tell you its pretty weird when you blow air with high speed (far enough so its comparable you nitpicker ) precisely directed at the small void between the Oettinger cylinders, your face is directly under it (yes, I'am weird too) and you feel NO air in your face!
If that defies the laws of physics, I believe you if you believe it, but I was probably just not such a good student
(though its more likely just a basic following of Bernoulli's law )

Anyways, my engine seems to be cooling pretty well

Why has everything to be so difficult with you Richard when I am stating s/th I experienced?

[Type 4 Unleashed]

Walter you remember this Topic ?

DTM and "under cylinder tins", are they fully needed ?

What about it? I used modded type 4 tins under 964 cylinders? Yes, you should, as those square jugs leave BIG holes between them when used on a type 4! Duh!
Lemme tell you its pretty weird when you blow air with high speed (far enough so its comparable you nitpicker ) precisely directed at the small void between the Oettinger cylinders, your face is directly under it (yes, I'am weird too) and you feel NO air in your face!
If that defies the laws of physics, I believe you if you believe it, but I was probably just not such a good student
(though its more likely just a basic following of Bernoulli's law )

Anyways, my engine seems to be cooling pretty well

Why has everything to be so difficult with you Richard when I am stating s/th I experienced?

Some sort of tin is a necseeity to build upper plenum pressure above the cylinders and force more air through the heads..
The stock TIV tins are too restrictive and should noty be used with the DTM. In our testing they proved to drag down HP and not cool nearly as well or as even as the TI tins.

With no tins in place the air will simply blow to the path of lesser resistance, between the cylinders and not take any heat with it.

-------------
You have to have some tin there, else you lose alot of pressure and
no cooling system works without pressure!

Yes, without tins, all you have is velocity!

A decrease in velocity will have a proportionate INCREASE in pressure....


Learnt DAT in turbine skool!

I was not talking about your 964 cyl's, you just trying to change the subject...
Above some quote's from the topic.

The discussion is about: to tin or not to tin that is the question.

And your the one with the closed mind.