Lets Build a Lightweight Type 4

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Marc W

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Mar 31, 2017
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Colorado
A fellow EAA member offered to give me a VW engine since I fly a VW powered plane. It was in a black garbage bag when I picked it up and I didn't look at it since he was in a hurry. I expected it to be a bug engine but it turned out to be a 1700cc Type 4. My CX4 has a 2180 VW that was originally built by Scott Casler. It is a good engine except it oozes oil in several places. It does perform well but we always want more! When I bought the plane my field elevation was 76' MSL. Now my home field is at 5,200' MSL and I often fly at 12,000' to clear the surrounding terrain so more HP would not be a bad thing!

I read everything here on Type 4's. Most of it is rumor and opinion and some of it just doesn't make any sense. The only hard facts I came up with is that Limbach made engines based on the Type 4. The conventional wisdom is that the Type 4 is to heavy and to expensive. But nobody has actually built and flown one!

The fact is the Type 4 can be built with a much larger displacement than a Type 1. I think that can justify a little heavier engine. There seems to be parts available for the Type 4. I don't know what it would cost to build a Type 4 but even if it is more than a Type 1 it could well be justified since you can build a significantly bigger engine.

"Weight is the enemy"! I couldn't find much on Type 4 engine weights. One source said a long block weighs about 142 lbs. Mark Langford said his proposed Type 4 would weigh about 225, presumably with electric start and he also intended to use an extended prop shaft housing like Wittmans V-Witt. That had to add significant weight.

More later.
 

pictsidhe

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Jul 15, 2014
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North Carolina
You have scales? Good, take it apart and tell us what all the parts weigh!

If you can build a T4 with similar hp/weight as a type 1, it would be quite useable to someone.
 

Hot Wings

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Nov 14, 2009
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Rocky Mountains
The VW tp IV is a better engine from an engineering point of view. They just weren't built in the numbers that the Tp1 was so the parts ARE much more expensive, even if you stay away from things like the sodium filled exhaust valves. They are heavier because they are physically bigger, both in size and displacement

I've built many of the TpIV over the years, and still have a few cores but I wouldn't consider converting one for aircraft use. 3 other options would come first:
Pick a plane that could fly well with a Tp1
Build a Corvair
Build a Subaru.

My advice? Sell the Tp IV and use the money for a different engine.
 

Hephaestus

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Jun 25, 2014
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YMM
Some of the replacement magnesium blocks are universal now - type 1 or 4. Believe they're about 30lbs heavier than the basic type1.
 

Marc W

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Mar 31, 2017
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367
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Colorado
My question is what would a hand propped, flywheel drive Type 4 weigh? Pops says a Type 1 long block is 116 lbs, and his 1835cc engine weighs 141 lbs, so the accessories weigh about 25 lbs. If a Type 4 long block weighs 142 lbs. and we add 25 lbs. for accessories then the engine will weigh about 167 lbs. That doesn't sound so bad to me. My Type 1 with Diehl case and electric start weighs around that. Plus I have the weight of a remote oil cooler and remote oil filter to add to that. The Type 4 mounts the filter and cooler on the case and that would eliminate the weight of the plumbing and the oil in the plumbing. Plus I could get rid of the battery.

William Wynn says a hand prop Corvair weighs 205 lbs. That is to heavy for my plane. I am pretty sure a Subaru weighs more than that.

Weighing my engine is on the list of things to do. It's stuck under the bench and it will take some time to drag it out.

Is there a good Type 4 rebuild manual available?
 

Marc W

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Mar 31, 2017
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I weighed the engine. It weighs 164 lbs with the flywheel, valve covers and bails, and lower cooling tin. I don't know if there is any oil in it. This site: https://ratwell.com/technical/Weights.html#longblock says the flywheel weighs 14.5 lbs. So the long block I have should be about 150 lbs without the flywheel. So if we add the 25 lbs for carb, ignition, etc. we have 175 lbs. Not far off from what a Type 1 with electrical system weighs especially if you include the battery.

Mark Langford bought his Type 4 from Mark Stephens. Stephens went out of business but he appears to be back since he now has a website: http://markstephenshighperformance.com/. The prices I see on his website do not appear to be incredibly high. I know there is more to it than that but it doesn't look that expensive considering it is for an aircraft. I daresay it would cost less than a Pegasus O-100.
 

TFF

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Apr 28, 2010
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Memphis, TN
Flywheel drive is your only option. What I see is you are on your own. No parts available on the airplane side. How big of an engine do you expect to build over your 2180? Without making it much larger, you are not going to gain a lot of extra power. 2600? Anything less is not going to be worth the effort. Doable for sure, but it’s not a lot of pay and play. Draw through normalized turbo sure would be awesome. If leaks are giving you thoughts, I would reseal it. Cheaper than a whole new engine.
 

Pops

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With the weight, cost and power produced, I would build a Corvair engine.
 

Mcmark

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Sep 24, 2013
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Owings, MD
Jake Raby, the type4store.com is one of the most knowledgeable about that engine period. Don’t know him personally but has great rep.
 

Marc W

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Mar 31, 2017
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Colorado
I agree. It would have to be at least 2600 to make it worthwhile. Stephens shows a 2650. That is a 21% increase over the 2180. Stephens also shows a 2922 for a couple hundred more than the 2650. That is 34% bigger than a 2180! All else being equal, for $200 I would go bigger. Another thing is that it isn't possible to get sea level HP here and I don't like running at high RPM's so it would not be run hard.

You do give me an idea though. I could ditch the electrical system on the 2180 and install a turbo. That could turn out to be a wash weight wise at the cost of a different kind of complexity. I don't really care about speed. I would just like to have better climb for flying around the mountains.
 

Marc W

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Mar 31, 2017
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Colorado
Thanks, Radford. I had seen reference to the accident at Oxnard but hadn't seen the SB. The tapered spacer looks like a Mickey Mouse solution anyway. To much taper and there just isn't much there for the prop hub to grab onto. Using a flywheel drive would eliminate that problem.
 

Theodore959

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Nov 19, 2019
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You have scales? Good, take it apart and tell us what all the parts weigh!

If you can build a T4 with similar hp/weight as a type 1, it would be quite useable to someone.
I have four "cores" all from vw bus/transporter , These are not high mileage vehicles, rec verticals parked most of the time. Valve seats let loose when they overheat. I use only case and crank anyhow.
I will weight all parts, trying to hit 140 total
 

Marc W

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Mar 31, 2017
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367
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Colorado
Thank you for your efforts! I look forward to seeing the results.

My T4 remains under the bench. I don't know when I will get to it. To many other projects in the way and I owe my wife a better kitchen.
 

mullacharjak

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Nov 5, 2010
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143
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Peshawar Pakistan
Its strange that no one is building a homebuilt Type 4 engine.I am sure junkyards should have plenty of cores or maybe not. I have seen one run on a Valentin Taifun glider (2400cc) and it runs very well. It was a limbach converted engine.The said glider wore out 3 engines the TBO being 950 hours.Never had a dead stick.
I had a conversion manual about 20 years ago by a brit author.He made a special bearing for the flywheel end I think.
The type 4 needs a look by all amateur builders .
 

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Bill-Higdon

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Feb 6, 2011
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523
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Salem, Oregon, USA
My question is what would a hand propped, flywheel drive Type 4 weigh? Pops says a Type 1 long block is 116 lbs, and his 1835cc engine weighs 141 lbs, so the accessories weigh about 25 lbs. If a Type 4 long block weighs 142 lbs. and we add 25 lbs. for accessories then the engine will weigh about 167 lbs. That doesn't sound so bad to me. My Type 1 with Diehl case and electric start weighs around that. Plus I have the weight of a remote oil cooler and remote oil filter to add to that. The Type 4 mounts the filter and cooler on the case and that would eliminate the weight of the plumbing and the oil in the plumbing. Plus I could get rid of the battery.

William Wynn says a hand prop Corvair weighs 205 lbs. That is to heavy for my plane. I am pretty sure a Subaru weighs more than that.

Weighing my engine is on the list of things to do. It's stuck under the bench and it will take some time to drag it out.

Is there a good Type 4 rebuild manual available?
I' say go for it I found this
A big difference between a Type 1 & a Type 4 conversion is the heads on the Type 4 have much better cooling
 

Bill-Higdon

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Feb 6, 2011
Messages
523
Location
Salem, Oregon, USA
View attachment 91527 View attachment 91526 One has said "Robust" re: T4, I agree...
I'av seen dat vid from Jeremy, I like his 'redneck' accent. (from Tejaus i suppose)
Have rotating assembly balanced after turning flywheel, add the spool extension too.

Pic from Bob Hoover Blog
IF you have access to Hoovers drawings they would give you a head start, and you could use a lot of parts from GPASC
 

mullacharjak

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Nov 5, 2010
Messages
143
Location
Peshawar Pakistan
I recalled the Brit persons name now.Mr.Peacock to be precise.Found the drawings too.Its a miracle I could find them after 25 plus years from a dusty pile!I am sure I would have built a homebuilt version but we dont have T4s here,not a single one.
 
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