Industrial engine displacement

[Mertz]

So an IND 5 is supposed to be 218ci. Mine is bored 40 over and has a bore of 3.28” which is smaller than the standard bore. The stroke is 3.62” which is way shorter than the 4.5”. By my calcs, even with the over bore, the displacement is only 183ci. The engine has been completely rebuilt so I don’t want to make changes. 

 

Is this a special engine?  I thought the smallest displacement was 201 but I did find some Canadian blocks as small as 160. The shortest stoke I could find is 3.75” most were 4.25” and up. 

[greg g]

How  did you measure the stroke?

[Mertz]

With my electronic gauge using the stem and double checking with a stick and the gauge. The old engine has the pistons much deeper in the holes. They measure about 4.25”. I guess this is good for high rpms but I need torque at low rpms. They must have done this for less wear on the engine while using it as a stationary engine.

 

can I just change pistons to increase stroke?  

[Mertz]

Top of the piston to top of block with pistons at the bottom of the stroke. 1 and 6 TDC

[LazyK]

1 hour ago, Mertz said:

 

can I just change pistons to increase stroke?  

Stroke is determined by the crank shaft.

Edited October 6, 2021 by LazyK

[Mertz]

I was thinking about pins higher up on the piston and a change in connecting  rod. The crank would be the first place to start. I don’t have a replacement for either. I’ll use it as is and maybe someday rebuild the 1936 Airstream engine I’m been given. 

 

BTW. The valves on the original engine are 1.46” for both intake and exhaust while the industrial engine has 1.41” exhaust and 1.52” intake. Maybe it will breath better and offset some of the lack of displacement. 

 

I know the compression ratio on the original is about 5.2:1. Is there a way to determine compression ratio on my engine?

[kencombs]

Measuring compression ratio require two things:  A way to measure a liquid accurately in cc's.   Burette, big syringe etc and math.

 

Determine the cylinder swept volume from bottom to top.  If the pistons do not come all the way even with the block deck that space is part of the combustion chamber, not the cylinder volume.  Determine the combustion chamber volume by filling the head portion with a fluid and your burette or syringe.  Calculate the portion of the cylinder volume not displaced by the piston travel (see above). Now calculate the volume of the head gasket 'gap'.  Add all three to get the chamber volume.

 

All measurements must be in the same units, cc's are most common. 

 

Divide the cylinder volume by the number arrived at above.  Compression ratio!

[lostviking]

23 hours ago, Mertz said:

So an IND 5 is supposed to be 218ci. Mine is bored 40 over and has a bore of 3.28” which is smaller than the standard bore. The stroke is 3.62” which is way shorter than the 4.5”. By my calcs, even with the over bore, the displacement is only 183ci. The engine has been completely rebuilt so I don’t want to make changes. 

 

Is this a special engine?  I thought the smallest displacement was 201 but I did find some Canadian blocks as small as 160. The shortest stoke I could find is 3.75” most were 4.25” and up. 

Stock bore for a 218 is actually 3.25.

[Mertz]

I just did the calcs and because the stroke is so short I get a CR of 3.27:1. That is unacceptable. Volume on top is 152.9cc and cylinder volume is 501cc. 

[Mertz]

Do they make domed pistons for my flathead?

[Mertz]

Do they make domed pistons for my flathead? Or pop up pistons.

[kencombs]

That is a huge combustion chamber volume!  I'd double check the measurement.  I think my 230 head volume was less than 1/2 that.

[Mertz]

Yes I need to use something more accurate. I used a calibrated wine testing tube calibrated in ml. I thought the gasket volume was to high as well. I think I’ll put on the head with the old gasket and try it that way. I was getting some capillary doming on the head test. What are other people getting for combustion chamber volume?  I think it is still going to be low given the short stroke. 

[kencombs]

33 minutes ago, Mertz said:

Yes I need to use something more accurate. I used a calibrated wine testing tube calibrated in ml. I thought the gasket volume was to high as well. I think I’ll put on the head with the old gasket and try it that way. I was getting some capillary doming on the head test. What are other people getting for combustion chamber volume?  I think it is still going to be low given the short stroke. 

That confused me!   The measurement must be done on the bench.  I know of no way to ‘put on the head with the old gasket and try ….’

 

the capillary doming can be handled in one of two ways.   One, make a clear plastic cover for one chamber with one hole to introduce the fluid and seal it to the head with a grease film ..  or use a fluid with less surface tension.  Water with a little dish soap or my choice diesel or kerosene.  In either case careful leveling is mandatory. 

Edited October 7, 2021 by kencombs

[Dodgeb4ya]

The IND5/5A engine can be either a 218 or 230 USA engine. Produced 1940 to 1955.

Uses the 23" long head.

The 218 = bore 3.250".....stroke 4.375"

The 230 = bore 3.250......stroke 4.625"

This information is out of the master Federal Mogul parts/specs and applications books.

I cannot find any MoPar  flathead back to the 30's with a 3.62" stroke.

A very short stroke for sure.

Not sure about that short stroke#.

 

 

 

[LazyK]

13 hours ago, Mertz said:

I was thinking about pins higher up on the piston and a change in connecting  rod.

Changing the connecting rod or piston could have an effect on your compression ratio but will have no effect on the stroke. The only way to change the stroke is to change the crank.

Typically an increase in stroke is to increases torque. A decrease in stroke is to increase RPM. 

[Mertz]

I did find some info on shorter stroke engines having 3 3/4” strokes. These where built around 1927 to 1930. I think some are Canadian. My guess is that since this was used as a stationary engine someone wanted efficiency and high revs. They must have found a short throw crank somewhere. 

 

I will I’ll recheck the head volume by putting an old gasket on the head set in sealant the a metal plate on top of that also set in sealant. I will then camp everything together and fill the chamber. I have a 60cc syringe I will use to add water. 

[Mertz]

Did the chamber volume check as described above. Used a glass plate but could not drill a hole in it so I used the spark plug hole to fill it. I ended up with 110ml or 110cc. I calculated the piston drop at 5cc for 115cc. So that works out to 4.356 CR. Still to low. If I shave the head I can add about 0.7 for a total of around 5. Pop up pistons would be easiest if I want a little more CR. Up 1/8” is probably all I’d want. 

[HotRodTractor]

I think you need to double check your stroke measurement. Something is off. 

[greg g]

Just reviewed the info for Chrysler engines shortest stroke mentioned is late 20s 4 cylinder at 4 1/8. Inches.  So you probably not dealing with a stock crankshaft.  Lookng at other brands of flathead engines also doesn't reveal an under 4 inch stroke.

 

Jeep, Willis and Oldsmobile showed 6 cylinder engines with 3 1/2, and 3 7/8  those are the only under 4 inch shown in that specs listing pages linked.

 

Something hinckey going on there.

 

http://carnut.com/specs/index.html

 

 

 

Edited October 9, 2021 by greg g

[Mertz]

The 1938 and 1939 Canadian made 201 had a 3 3/8” bore and 3 3/4” stroke. The 1928 and 1929 had a 3 3/8” bore and a 3 7/8” stroke in the 208. The numbers are posted on wikizero.com. I have the engine at TDC and measured the cylinders that were down and took the measurements from the deepest one. I assume that at TDC at least one cylinder is at the bottom of its stroke. 

 

https://www.wikizero.com/en/Chrysler_flathead_engine

[kencombs]

12 minutes ago, Mertz said:

The 1938 and 1939 Canadian made 201 had a 3 3/8” bore and 3 3/4” stroke. The 1928 and 1929 had a 3 3/8” bore and a 3 7/8” stroke in the 208. The numbers are posted on wikizero.com. I have the engine at TDC and measured the cylinders that were down and took the measurements from the deepest one. I assume that at TDC at least one cylinder is at the bottom of its stroke. 

 

https://www.wikizero.com/en/Chrysler_flathead_engine

I don't think that assumption is correct for any six cylinder engine.  The crank throws are not 180deg apart.  Put one at bottom and measure.

[Merle Coggins]

You assumed wrong… When 2 of the pistons are at TDC 2 others are on their way towards the bottom and 2 others are on their way up. They are 120 degrees apart. 

[Mertz]

Well you know what they say when you assume. You make an ass out of u and me.  Rotated the crank and got the piston down to the bottom and got a measurement of 4.437”. The piston is in the hole 0.030”. The final cylinder volume is 609cc.  The camber is 115cc so CR is 5.295. Total cubic inches is 222.96ci with the 40 overbore. 

 

Thanks everyone for straightening me out.