| Author |  Topic  |
Vedrive
Starting Member
Netherlands
44 Posts |  Posted - 04 Sep 2022 : 12:37:15  
| Dear Saab V4 enthusiasts, my name is Bonne, I live in Holland.
Currently, I am working on a Ford V4 engine for a full restoration vehicle project Matra M530.
In my search for V4 parts I came in contact with Melle who pointed me to this forum. (Melle thanks for that).
I am impressed by all the V4 knowledge and great projects in this forum, so I like to share some ideas and I would be happy to receive your comments and advice or other.
I decided to do "something" with the Ford V4 engine, this "something" is still an open book, and will be driven by availability of parts (that does not cost an arm and leg) and most important, gives me fun to do.
But the first technical problem I have to solve is how to add images to this forum which I hope to solve soon.
For now will add a link to my topic in the Matramania forum, text is in Dutch but I think scrolling the images may give some idea of my Ford V4 activities such as:
-simple flow bench measuring system
-flow preparation and port analyse with cross sectional drawings
-Vee pipe , individual exhaust pipe per cylinder investigatin
-Supposed balancing theory Ford V4 engine with balancing shaft, some question left.
-Injection, first step injector set up
https://www.matramania.be/phpBB3/viewtopic.php?f=4&t=3839 |
Edited by - Vedrive on 04 Sep 2022 13:00:45 |
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melle
V4 Guru
United Kingdom
4145 Posts | |
Vedrive
Starting Member
Netherlands
44 Posts | Posted - 05 Sep 2022 : 11:16:53
| Thanks Melle, looking forward to meet again, maybe with small ride in the Devil's own. Although I must be carefully not to be infected to much with the Saab96 virus. Not easy with that great race history.
Did already read the posts and faq on the how to post image, I have no access (yet) to Flickr alike site
Tried some other but w/o succes.
For right now, as temporary? workaround, I will launch a clean link af the image in my tekst just need to open, no scrolling needed.
Sample image of a part all started with, a bare V4 open Deck block.
https://www.matramania.be/phpBB3/download/file.php?id=10266
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Edited by - Vedrive on 05 Sep 2022 13:25:52 |  |
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chris steeden
V4 Fan
United Kingdom
177 Posts | Posted - 06 Sep 2022 : 12:31:48
| A warm welcome to the site Bonne. Your work on the V4 engine looks very interesting - well done!
I wish that I could read Dutch as your blog on 'matramania' seems brilliant. I will have to load
Google translate and read it. Keep up the good work. | |
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Vedrive
Starting Member
Netherlands
44 Posts | Posted - 06 Sep 2022 : 18:34:29
| Thanks Chris,
My intention is to bring up the V4 issues also in this forum for discussion in English.
(Else a crash course in Dutch may help...... )
//Bonne | |
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AnttiK
V4 Fan
Finland
115 Posts | |
Vedrive
Starting Member
Netherlands
44 Posts | Posted - 07 Sep 2022 : 16:58:24
| Great job AnttiK, with a robust design.
Nice to see we are on similar thoughts.
Have read your threat, I am very impressed by your work.
I measured with a dual port, split big exhaust hole and a flowed port and standard exhaust valve about 20% flow improvement compared to standard.
I am glad with that improvement as as the amount of exhaust gas is half (1cylinder) as the single port.
Plan to do some more flow test in future, keep you informed.
By the way do you plan a 4 in 1 pipe with proper tuned pipe length, In the Matra lay out (mid engine) that will not be possible.
(So 4 open exhaust pipes with 6 degree megafones like the Old English racers are an option, think my wife and the whole neighborhood will disagree)
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AnttiK
V4 Fan
Finland
115 Posts | Posted - 08 Sep 2022 : 06:16:50
| I am going to make 4-2-1 exhaust using about 60cm primary pipes, because it is easy to do for 96. Unfortunately 1+2 and 3+4 cylinders are not correct cylinder pairs after primary pipes to get full benefit. 1+4 and 2+3 would be the correct pairs, but it is quite difficult to make that kind of exhaust manifold to V4 engine with proper pipe lengths.
4-1 exhaust manifold could be done to V4 engine, where collector is over the flywheel/clutch, but I think it takes too much space from engine bay. | |
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Vedrive
Starting Member
Netherlands
44 Posts | Posted - 14 Sep 2022 : 20:20:44
| Ford V4 engine balancing.
Image 1. crankshaft/ balance shaft/ camshaft.
https://www.matramania.be/phpBB3/download/file.php?id=10397
I arranged a set of new old stock forged Ford OHC pistons for a reasonable price.
As piston weight change for this type of engine may impact engine vibration level I was curious how to balance such an engine.
As far as I could find crankshaft balancing is done the traditional way with 50% bobweights For the balance shaft Melle pointed me earlier to an interesting topic in this.
http://www.saab-v4.co.uk/speedball/topic.asp?TOPIC_ID=33271 and informed me that according to Saab S&R catalogue a 1500 balance shaft is advices for tuned 1700 engines .
Both seem to give satisfied results, but for me thats not enough so more than enough reason to have a look at the crankshaft/ piston geometry related vibration.
I am aware some basic knowledge is required, but there is sufficient material available on the internet.
Anyway first a bit of basic theory with graphical support .
Below image a typical graphic representation of the cylinder piston acceleration behaviour of a one cylinder during 1 engine revolution.
Image 2.
https://www.matramania.be/phpBB3/download/file.php?id=10398
Vertical axis show the behaviour of the piston acceleration or also the reciprocating Force (as F = m*a)
To make it general for al engines it is a relative scale where the peak of the 1st order is set to 1. The horizontal axes is the crank angle.
The yellow line represents the total piston acceleration.
This yellow line is technically composed of a primary or 1st order acceleration (green) and a secondary 2nd order acceleration (red).
(Note: Theoretically there are much higher orders but as higher the order the lower the magnitude, it is common to ignore this.)
As an example I have drawn some arrows called vectors, these vectors represent the magnitude and direction of the piston reciprocating acceleration/forces.
For a piston this is always in the cylinder direction, so for a V engine this is different according to the cylinder angle of direction.
As example I have drawn a 1st order green vector when the piston is @ 0 degree (TDC) and a 2nd order @180 degree. I will transfer them to the V4 in the next image in a direction according to the cylinder angle. Likewise you can do for every crank angle position. This way you can play with all type of engines, X-cylinder in line or V, big beng, cross plane or whatever engine you like.
The 1st order (also known as primary) vibration means the vibration has the same frequency as the engine speed.
The magnitude (so green vector length) of the 1st order vibration is: Mz*w^2*r*cosine(a)
Where:
-Mz is the reciprocating mass (is the weight of the piston related up and down moving parts (the internet gives sufficient info how to measure that for your engine.)
-w^2 (pronounced omega squared) the square of the angular rotation, the speed, in radians per second).
- r is crank radius, this is half the crankshaft stroke.
- cosine (a) , (a) alpha is the crank angle of the crankshaft during its revolution.
The 2nd order (also secondary) vibration means the vibration frequency is twice the engine speed, the red Vector has a
Magnitude of: Mz*w^2*r*(r/L)*cosine(2a). Note: formula typo corrected 21/10, one r was missing.
Where
-r/L is the crank/connecting rod ratio, L is the connecting rod length.
-cosine(2a) frequency 2x crankangle speed, hence 2nd order.
Now lets go to V4
Pls keep in mind this is my supposed idea as far I could analyse based on the geometry of the engine set up. It is not confirmed by measurements. I hope to be able to do some work on that in the future.
Image 3.
https://www.matramania.be/phpBB3/download/file.php?id=10399
The image shows the crank pins of the front two cylinders #1 and #3 . The rear cylinders #2 and #4 are not drawn but are mirrored to the right side.
Cyl #1 is at 0 degree (TDC), cyl #3 is at 180 degree (BDC).
The vectors derived from image 1 have been introduced into this image.
As this vectors in the V4 do not all work in the same direction as the cylinders are at 60 degree angle, I resolved them into a horizontal and vertical component.(dotted lines).
The magnitude of this dotted vectors can be derived from the 60 degree cylinder angle. (famous Pythagoras triangel )
The horizontal magnitude component is 0,5 * the vector (or 50%, remember this!)
The vertical magnitude component is 0,5*(3^0,5) * the vector. Read (3^0,5) as square root of 3
If we look to image 2, the first order vertical vectors (vertical green dotted arrows) are opposite and therefore cancel out each other so no vibration impact.
The horizontal first-order vectors ( horizontal green dotted arrows) of cyl#1 and /#3 point to the left and reinforce each other. The horizontal vectors of cyl#2 and #4 ( Although not in the sketch) are mirrored and point to the right.
Due to the cylinder distance (C) of cyl #1-#3 to #2-4, tries to give the engine what we call a horizontal momentum force or a rocking vibration.
The magnitude of this horizontal first order rocking momentum is: Mz*w^2*cosine(a)*C. Note typo correction (a) instead of (2a) as its first order.
(-actually 2*0,5 as its but this =1)
-where C stands for cylinder distance
This horizontal vibration is in my opinion balanced with by the counterweights of the balance shaft and a part of the crankshaft.
As we can see in image 3 the counterweight of the balance shaft and a part of the counterweight of the crankshaft also have a force vector.(Which is rotating with the engine speed, hence 1st order.) In the drawn position this is opposite to the 1 st. order of the piston force and thereby balancing this vibration.
The reason I say a part of the crankshaft counterweight is that as the crank and balance shaft run as 2 counter running shafts where the counterweight unbalance only work in horizontal direction, when the counterweights are in vertical direction they are opposite of each other so they cancel out.
The other part of the crankshaft counterweight is used to balance out the rotating mass of the crankpin and lower part of the conrod.
THERE IS ONE BIG "BUT"
I donot know to what extend the balance shaft is designed to balance the related piston acceleration forces. I have no equipment to measure this. Could be 100%, could be less due to some kind of design constraint such as space limitation or perhaps bearing loads.
The 2nd order vibration.
If we look at the red dotted vertical vectors we see they all work in the same direction, this counts for cyl 1 and 3 but also for 2 and 4 causing a vertical (up and down) engine vibration.
The the magnitude second order vertical force is 2*Mz*w^2*r*(r/L)*(3^0,5)*cosine(2a)
This vibration is comparable to the vibration of a traditional 4-cylinder in-line engine, only it is slightly less here (2*0,5*(3^0,5) i.o.4 ) due to the cylinder angle of the V engine. This is normally not balanced (as done on some 4 cyl in line engines with 2 balance shafts running doubleat twice the engine speed)
The the secondary horizontal red dotted vectors of cylinder 1 and 3 are opposed to each other meaning they cancel out and there is no horizontal 2e order vibration.
So far for the theory.
Balancing Ford V4, with some questions.
This crankshaft is not dynamically balanced by itself like f.e. a traditional 4 in line engine. So likely for balancing bobweights are used.
Note added 21/10 tekst modified as i noticed misunderstanding discussing this issues with an automotive friend /college.
If we assume the horizontal rocking vibration is 100% canceled out by the crank and balance shaft counterweights, both have to take 50% by counter running direction.
This 50% for the V4 it a mathematical calculated value for the horizontal vibration due to the geometry of 60 degree cylinder angle (you often find this" 50% value" for other cylinder configurations, this is to lower the upper first order vertical vibration peak for averaging upwards and downwards peaks and internal stresses, this is more or less an arbitrary value)
In the crankshaft this can be done with traditional bobweight cintaining the rotational mass and looking to figure 3. The 50% reciprocating mass is divided over 2 cylinders #1, #3 (and #2 ,#4 on the rear side.
As the balance shaft should be balanced to take the other 50% of the horizontal vector but this is not so easy.
Since the imbalance weights are much further apart than at the main crank counterweights (at cylinder distance), the moment increases, so these weights have to be calculated back to the right value. . Also note that part of the balance weight is in the drive sprocket.! I will see if I van make a simple balance shaft measuring device.
A reason to advice a 1500 balance shaft in a tuned 1700 machine could be that for a tuned 1700 a lightweight (forged) piston is used which require a less (dynamic) balance shaft counter weight according my calculation. A 1500 shaft may have already less counterweight due to the lower stroke. (the value "r" in my calculation.) This seem logic but still is a gues.
Question, does somebody has balanced his crankshaft on a balancing machine? How was it done, reciprocating weights of pistons? and bobweight % was it 50 of other.
Was the balance shaft also balanced?
I would be greatfull if somebody wants to share his results.
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Edited by - Vedrive on 01 Jul 2024 16:42:35 | |
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AnttiK
V4 Fan
Finland
115 Posts | Posted - 15 Sep 2022 : 06:19:37
| Have you noticed that piston pin is not in center in V4 standard piston? If you look at for example Melle's sales topic with 1.5 and 1.7 piston pin location:
http://saab-v4.co.uk/speedball/topic.asp?topic_id=16437
I measured my 91.3mm Mahle OHC pistons and in those piston pin is in center. V4 standard piston pin placement is designed to reduce vibrations and OHC piston pin placement will probably add some vibrations, but it should be give slightly more power output. |
Edited by - AnttiK on 15 Sep 2022 10:04:42 | |
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melle
V4 Guru
United Kingdom
4145 Posts | Posted - 15 Sep 2022 : 08:18:02
| Thanks for pointing that out Antti. I did of course know V4 pistons are directional (hence the crowns being marked with a notch), but would you believe I never noticed the pins are offset! I just measured one, the pin is about 3mm off centre.
www.saabv4.com | |
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AnttiK
V4 Fan
Finland
115 Posts | Posted - 15 Sep 2022 : 10:14:03
| After Reading the Wiseco article about the piston pin offset I am not really sure if the Mahle OHC piston pin offset is precisely zero, but definitely less than V4 standard pin offset 3mm.
https://wiseco.com/blog/what-is-wrist-pin-offset
Also it is said in the article that with the offset designed for engine the power output should be greater due to less friction. This is different when compared to other sources I have read.
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Vedrive
Starting Member
Netherlands
44 Posts | Posted - 15 Sep 2022 : 10:20:33
| Good info AantiK. I did not measure (should have done  ) although I expect some pin desaxation as engines of that time i have seen often had something about 1mm. As Measured by Melle 3mm is quite a lot.
For the balance theory I am focussing primary on the mass issues as the balance shaft counterweights should somewhere compensate other mass (as piston reprocicating mass) I reviewed piston desaxation in the past in the piston movement and therefore speed and acceleration, but. Impact was marginally.
Piston pin offset is as far as I know normally used for noise reason, I was not aware of vibrations or how that would work, exept than the bouncing impact of tilting piston at TDC, very interessting.
Another thing is engine desaxation crank not in line with cylinder, used to "elongated" the powerstroke or effect piston side pressure, ( some old Ford engine had that also) I hope the V4 hasnt, or??
In the past I have reviewed piston pin desaxation, (think it was 1 mm)in the piston stroke movement and therefore acceleration but that was so small I neglected this later on.
I will review though with the 3mm from Melle.
Thanks for feed back. All help greatfull to see if we can come somewhere.
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Edited by - Vedrive on 15 Sep 2022 13:48:25 | |
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melle
V4 Guru
United Kingdom
4145 Posts | Posted - 15 Sep 2022 : 10:34:14
| Correction, I measured 3mm more on one side of the pin compared to the other, so the offset is of course 1.5mm, not 3.
www.saabv4.com | |
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Vedrive
Starting Member
Netherlands
44 Posts | Posted - 15 Sep 2022 : 13:56:14
| Thanks Melle.
Thats closer to what I used to, next time when I am in the workshop I will do some more measurements on the V4, forged OHC and V6 Piston.
AnttiK, almost mist yr Wiseco reply, think I was typing myself.
I will measure my Wisecos, they are old skool, nowedays CNC designs are much lighter.
https://www.matramania.be/phpBB3/download/file.php?id=10298 |
Edited by - Vedrive on 15 Sep 2022 14:12:11 | |
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Vedrive
Starting Member
Netherlands
44 Posts | Posted - 21 Oct 2022 : 19:06:59
| I have made some corrections to the supposed balancing theory of the V4. They are marked with the date 21/10
I noticed a few typo's and discussing balancing issue with a friend noticed some tekst could lead to confusion.
I am triing to make a small bench to measure the "corrected" dynamic imbalance of the balance shaft but not so easy.
By the way, static measurenents on 2 horizontal edges show it is static out of balance. I suppose the crankshaft is static in balance?? Somebody has Measured?
If any of you have some practical information about dynamic balancing the crankshaft, counterweights etc.info to share is highly appreciated. |
Edited by - Vedrive on 21 Oct 2022 19:08:04 | |
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| Topic | |
Ford V4 engine for a Matra M530
