71 x 103 engine

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dklipfel
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Post by dklipfel » Tue Feb 28, 2006 1:21 pm

My 2367 cc is also a 71 x 103. The case was a 914 1800 and the heads came from a bus. The important thing I did after a few miles is to open up the valve size to 44 intake and 40 exhaust. That and a 4-1 BAS header and retuned Webers resulted in a totally diferent engine. Breathing "life" into the engine if you will.

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Bobtail
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Post by Bobtail » Tue Feb 28, 2006 1:27 pm

dklipfel wrote:My 2367 cc is also a 71 x 103. The case was a 914 1800 and the heads came from a bus. The important thing I did after a few miles is to open up the valve size to 44 intake and 40 exhaust. That and a 4-1 BAS header and retuned Webers resulted in a totally diferent engine. Breathing "life" into the engine if you will.
The curious side of me wants to know what cooling youre running?

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Post by Type 4 Unleashed » Thu Mar 02, 2006 1:58 am

I, run stock type lV fan and tin, I, run 105.7mm cast iron cylinders, and I was running 12.2 to 1 C/R. Since then I drop the C/R down to 10 to 1, but thats no fun, so I'am gonna go back up to 11 to 11.5 to 1.

Cooling is an issue, and I've found by blue printing the head cooling, makes a world of difference.

All, I do is remove every air flow restriction in the head. Look down between the intake ports on a type lV head, and what you see, casting flash, and everywhere else.

I, take a long drill bit & drill, a slim rat tail file, a cut off wheel and grinder and go to work. What I do with the cut off wheel and grinder, on the outside of the head, their is a casting ridge on each fin, which restricts air flow, I remove them.

After, 3 to 4 hrs, I have a pair of heads, with a substantial increase in cooling capacity.

My, car is a daily driver, and I drive out in Riverside, quite often, where temps in the summer, are over 100 deg.

I've, droped my bore size down to 105mm, I won a set of used Weisco 12 deg 4.135" (105mm) bore pistons, 8 for $79, that are going in my motor with the Dodge bearing modified Toyota rods. And I'am now looking for a set of 4.180" bore (106.2mm) pistons to go in my 105.7mm cyl's. :twisted:
Richard

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Piledriver
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Post by Piledriver » Thu Mar 02, 2006 5:42 am

V6914, I strongly suspect you are right about the casting flash removal...

A fellow with a stockish bus was having "hot head" issues and was pulling his hair out here a few months back..

Did the same thing, the "imbalanced" head temp dropped ~50F right down to match the other, which had less flash to begin with. (I'm sure he did both heads, or wishes he did).

There isn't much air flowing really, seems logical that small improvements could make a huge difference here, even surface texture.

Do you run racing gas all the time?
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Post by Type 4 Unleashed » Thu Mar 02, 2006 11:27 pm

Quote
There isn't much air flowing really,

I've been under my car when it's been running, and the amount of air flow at idel, I thought was quite alot. But, I forgot to mention, my stock type lV fan shroud, flows a little better than normal, I've added 2 reflectors, that block air flow to the heater outlets, I, figured since I don't have heaters, the air flow that would of gone to the heaters, would better help cool the engine.

Quote
Do you run racing gas all the time?

With, the 12.2 to 1 (static of 200 psi) I, did have to mix a gallon of 112 octane to every fill up :lol: , and it was a fairly expensive, pain in the neck.

I, did have the intire chamber's ceramic coated, except where the cyl, seated on the head, and that included the valve faces, and the intire exhaust ports. My, next heads, I'am just gonna have the valve faces done, and the exhaust ports.
[/quote]
Richard

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have the money to do it right, but can always
find the money to do it twice ?”

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func412
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Post by func412 » Mon Mar 06, 2006 2:11 am

V6914 wrote: I forgot to mention, my stock type lV fan shroud, flows a little better than normal, I've added 2 reflectors, that block air flow to the heater outlets, I, figured since I don't have heaters, the air flow that would of gone to the heaters, would better help cool the engine.
That´s what I thought also. You can find some discussions in this forum which handles this issue. As a result of those threads I´ve understood that blocking those outlets just makes air flow worse. I haven´t tested it yet, but I think those warnings are based on experience. The way you block those outlets may make some difference also.

70dragbug
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Post by 70dragbug » Mon Mar 06, 2006 3:31 am

103x71 type 4 is the most common type 4 engine here in Germany.Most of them have around 160 HP.Cooling problems are very rare.I believe that the most common cause for high head temps are due to improper head work i.e improper porting, machining the combustion chambers too deep,etc.Most engine failures here are due to spun bearings because of the constant high rpms on the autobahn or just plain abuse and lack of proper maintenance.In southern Germany the summers can reach 100°F aswell-combine that with autobahn speeds.Almost all type 4´s here run 911 style fanshrouds.
Expansion issues/head leaks aren´t that common either here.Although engines with a 105 bore seem to have head leaks.This is as Jake said, due to the offset stud pattern and lengths,which is why most builders here recommend a 5 or 6 stud set up with a 105 bore.Type 4 head and a 105 bore don´t really get along and there is no gain in horsepower/torque over the same combo with a 103 bore.

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Piledriver
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Post by Piledriver » Mon Mar 06, 2006 5:05 am

V6914 wrote:Quote
There isn't much air flowing really,

I've been under my car when it's been running, and the amount of air flow at idel, I thought was quite alot. But, I forgot to mention, my stock type lV fan shroud, flows a little better than normal, I've added 2 reflectors, that block air flow to the heater outlets, I, figured since I don't have heaters, the air flow that would of gone to the heaters, would better help cool the engine.
What I was trying lamely to say was that as the head passages are so small, it likely doesn't take much to improve cooling greatly by cleaning them up as suggested.
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Bleyseng
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Post by Bleyseng » Mon Mar 06, 2006 10:31 am

I remember someone testing this and blocking off the HE fan ducts actually decreases flow as it backs the air up inside the fan. If you are running without HE's leave them open.


Geoff

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Post by MASSIVE TYPE IV » Mon Mar 06, 2006 10:34 am

Bleyseng is 100% correct. The shroud was designed to have a constant loss of air to the HE at all times. Blocking off these outlets creates a change of pressures within the blower housing that isn't favorable.

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Wally
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Post by Wally » Tue Mar 07, 2006 2:17 am

MASSIVE TYPE IV wrote:Bleyseng is 100% correct. The shroud was designed to have a constant loss of air to the HE at all times. Blocking off these outlets creates a change of pressures within the blower housing that isn't favorable.
I believe you there Jake, as you have tested this IRL.
Still, the latest type 4 engines ever made, the Vanagon CU-coded engines, have a factory improved fan housing without those heater ducts and without a duct for cooling the generator (as you know all too well). Otherwise, from the outside, they look thesame.
What is so different in that later shroud design that made it work better with those factory closed outlets? Is it a turbulance thing?

Tnx,
Walter
T4T: Type 4 Turbo engine, under construction

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func412
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Post by func412 » Tue Mar 07, 2006 6:44 am

I havent found an answer, does the flaps, covers and blower from 412 1700 cc engine fit to vanagon blowerhousing? Does someone know about this?

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dstar
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Post by dstar » Tue Mar 07, 2006 8:52 am

I have an 81 AC Vanagon shroud at home. I'm using the closed case
for the drag engine. :twisted:

I'll dig it up tonight and see what I can see.

I'll take pics if I think it's necessary to show the diffs.
Anyone got any online pics of pre-79 blower housing's internals?

Don

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Post by MRRAGPICKER » Sat Feb 28, 2009 5:16 pm

func412 wrote:Well, the engine project did get started. I just decided to start do-it-yourself project =)

I bought Deutz 100 mm cylinders and TRW 103,4 mm forged pistons. So some machine work must be done. Lets see what happens. This far I´ve been advised to take good care of engine cooling. All help is welcome.

I´m gathering information from you guys, specially who have built an engine with deutz cylinders.

How to:

-cylinder head work
-engine case work
-etc.

Thanks! I try to document this project while doing.
FUNC412
What ever happened to this? The Deutz Cylinder concept is interesting.
How would you cut it down to use? And what pistons would be usable in a 100mm Deutz 912 cylinder?

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Piledriver
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Post by Piledriver » Sat Feb 28, 2009 5:43 pm

101.6mm is 4".... so all the 4" range SBC/SBF slugs are free game over that size.
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