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Dougy90
02-12-2010, 02:43 AM
Im working on a design problem for the advanced engine design class i am taking right now. the assignment is to set up a spreadsheet showing piston acceleration with the corresponding primary and secondary forces. my professor has allowed us to pick any engine to analyze and show how the forces cancel eachother out or how they do not. I chose to analyze my motor (5sfe) and I need to know a few things in order to complete this assignment.

if anyone has the connecting rod length (measured from center to center) and the reciprocating mass (which includes the piston, wrist pin, any snap rings or locks, and the connecting rod) i could use this. I have the bore and stroke so im set there. I can figure what 1/3 of the reciprocating mass will be once i know the total.

if anyone has the parts laying around from a build it would be great if you could help me out. Dont worry if the measurments are not exact, the assignment is to get a sense for engine forces and kinematics.

Thanks everyone

pitcelica
02-12-2010, 03:13 PM
My contribution :

5SFE rod length : 5.42" = 138 mm

When you will have done this design problem, I would like to see the results and the calculations! Please post them when you are done!

Sam

Dougy90
02-12-2010, 08:24 PM
Its not due for a while but ill post the results up when i get a chance. it probably wont be until after the quarter is over. im spending a ton of time in the etec building working on building the BAJA SAE car for competition. thanks for everything

joe's gt
02-12-2010, 08:45 PM
primary and secondary forces? As is the force of the piston accelerating upward, the force of the rod stopping the piston, the force of the compressed air on the piston, the force of the combustion on the piston...? Which forces are you specifically talking about? I am an ME, so I am extremely interested in what your doing and the results you get.

Dougy90
02-13-2010, 04:25 AM
we are calculating the primary and secondary forces due to the motion of the piston. so im looking at the acceleration of the piston and the forces associated with that motion.

later on we will have to make a spreadsheet that takes into account the forces from the combustible gases. there has also been a bit a of an update to the assignment. my professor has changed the assignment to a I6 cylinder engine because he wants us to see that the primary and secondary forces will cancel out. My plan is to get the assignmen done for class and then go back and apply the numbers for the 5sfe. I know there is going to be a secondary imbalance (i am not taking into account the balance shafts) as most four cylinders have a secondary force imbalance.

I actually am enjoying this assignment because i get to use the knowledge i have gained in my classes now.

joe's gt
02-13-2010, 04:28 AM
we are calculating the primary and secondary forces due to the motion of the piston. so im looking at the acceleration of the piston and the forces associated with that motion.

later on we will have to make a spreadsheet that takes into account the forces from the combustible gases. there has also been a bit a of an update to the assignment. my professor has changed the assignment to a I6 cylinder engine because he wants us to see that the primary and secondary forces will cancel out. My plan is to get the assignmen done for class and then go back and apply the numbers for the 5sfe. I know there is going to be a secondary imbalance (i am not taking into account the balance shafts) as most four cylinders have a secondary force imbalance.

I actually am enjoying this assignment because i get to use the knowledge i have gained in my classes now.

cool. well be sure to post back the results of the calculations. I am interested in seeing what the results are.

Dougy90
02-13-2010, 04:31 AM
will do! it may be a while before i get a chance to post the results. BAJA SAE is taking up a lot of time and i did to finish designing the control arms for our upcoming car. and then ill be working designing a locking mechanism for the open rear differential. we decided to on a completely new design for next years car...so as u can see i have my plate full lol

thanks for the input everyone

KoreanJoey
02-13-2010, 06:36 AM
Are involved with UWs Formula SAE program?

Dougy90
02-13-2010, 06:22 PM
no im not at UW...im at WWU in bellingham. i was involved with the WWU formula sae but it didnt work for me (personel issues). im involved with the baja sae

joe's gt
02-13-2010, 07:31 PM
no im not at UW...im at WWU in bellingham. i was involved with the WWU formula sae but it didnt work for me (personel issues). im involved with the baja sae

I tried Formula SAE here at UC Davis and it didn't work out for me either. They wouldn't let me do any machining or welding which was one of the main reasons I joined and most of the design was done, and they were basically just doing everything the same as the last car they built. All they had me doing was wrenching, which I had already done for 5 years on my own car. They weren't mean or anything, they just basically didn't let me in on the specifics, so I bailed and have been working on my own projects that interest me.

Dougy90
02-14-2010, 01:59 AM
ya i hear you joe. when i was on the formula team here i pretty much just sat there and watched someone do something. i would rather learn how to do something and not sit there all day u know. so i switched over to the baja team the following year and the older team members allow the new guys to help design and fabricate components.

and while driving home today i realized something, i need to know the recipocating mass for the 5sfe. so if anyone has the mass of the connecting rod, wrist pin, snap rings or locks, and piston that would be great. I need the total reciprocating mass in order to calculate the forces. if no one has those ill be searching and i dont know if ill be able to provide the speadsheet.

appreciate the interest and help guys

Dougy90
02-17-2010, 10:48 PM
any help with the reciprocating mass?

Dougy90
02-26-2010, 01:24 AM
i have the forces for aan I-6 balanced out...does ne one want to see those?

I still wasnt able to find the reciprocating mass for the 5s

joe's gt
02-26-2010, 05:50 AM
Yes, Yes I do!!!!

Dougy90
02-27-2010, 02:31 AM
okay well im not sure how to post an excel file. its pretty big and not sure how to go about this..

ne help?

joe's gt
02-27-2010, 02:40 AM
okay well im not sure how to post an excel file. its pretty big and not sure how to go about this..

ne help?

Well if I'm the only one interested I can just pm you my email.