Author Topic: Fl 350 stroker project  (Read 4536 times)

Adnoh

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Fl 350 stroker project
« on: November 09, 2008, 06:17:33 PM »
I will start off will base stock #,s based on stroke of 68mm and bore of 80 mm.

Weed if you ae making kit to sale and not share with board I will stop and not interfear. If your doing a project for discussion and shareing I will proceed if board is interested.

Weed

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Fl 350 stroker project
« Reply #1 on: November 09, 2008, 07:23:25 PM »
I think that we should work together on it.  I don't mind sharing information and helping guys that want to build engines on their own as long as they do it right.  

I have found in the past is guys that want to build their own engines, don't know what they are doing.  Especially when it comes to high performance engines, tolerences, clearances, torques, and knowing what to look for and proper assembly procedures.  

Alot of guys end up doing more damage than good.  Yes it is good for my business but that is not why I started to sell parts for them.  I'm not in it for guys to blow up their engines and come back to me for more parts.

I have a watercooled head set up that I designed.  I could sell a pile of them but I don't want the liability.  80% of my customers probably don't know what "squish" is and wouldn't care to check it even though I stress that it is a nessisary part of engine building.

So with that being said, this experiment probably won't be marketed by me unless I am 100% sure it is dummy proof and shows significant potential.

Weed

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Fl 350 stroker project
« Reply #2 on: November 09, 2008, 09:43:13 PM »
Numbers to crunch for now.

89mm bore
79mm stroke
144mm rod length

your system is in ???? Excell?

Adnoh

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Fl 350 stroker project
« Reply #3 on: November 10, 2008, 01:14:30 PM »
Yes excell. Look like pilot #s with a 500 bore. I will crunch. Is this seperate from 350 stroker. If so got "LT" ( pipe tuned lenght),stinger dia and intake areas. Also exhaust duration.  I can get you close if you let me know what pipe and reed assembly. I will throw in diff carb dia for #'s. Rember this is a hacker set up not some down loaded professional job. Caint testify to accuracy. Good for Idea thu. Thanks for sharing just didn't want to step on any toes and get kicked.

Adnoh

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Fl 350 stroker project
« Reply #4 on: November 13, 2008, 04:17:44 PM »
You ready for this. Before throwing number at this let back up for the ones thats are asking why. I will try to keep short and break up in sections.

As stated in other post the pilot is a stroked 350 with a few other changes. Most of now that the pilot in stock trim has better power managment and reliablity.

Why should we stroke a motor and what can be gained. Knowing every one uses a diff application of power for different ridding ares and type of ridding we should first discuss this. A dunner should tune and build diff than a woods or racer. Dunner first, what type of dunning hillclimber trail runner or drag racer. A bore /stoke can be applied in theroy for each and be effective yet may suffer in other. I call this action reaction.

I proposese this. Since the 350 has too big of bore for its strok any way why not leave stroke alone decrease displacment and rev faster with a higher bemp and increas effective BHP and reliabilty.

Thoughts on idea. What would suffer from this. I like to consider reaction working toward effecinty. BHP is a plan which is the formula for brake horse power and can easy define the output. Plan is based on PSI,STROKE,AREA and RPM. change one and it has an effect on output.

I discussed a decreas in AREA and increase in RPMand PSI changing three things effecting BHP.

First; negitive effect on changing AREA. less port opening area,weaker carb single and less torgue.

I will slow up here and give an example. If I was a hill climber bad news,If I was a racer ok but not good, long distance trail runnung at speed OH YA.There is a lot other items that would bare on this but just leave them alone.

Second: advantage of RPM, developing a higher BHP at speed,and and higher g- max ( touch on it later ring thickness at speed)as well a higher top spped using a CVT transmission.

Ok got to go eat I'll finsh later. Look this over and ask questions if you not following me. It's important to get it now or you will really be lost later.

Adnoh

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Fl 350 stroker project
« Reply #5 on: November 13, 2008, 05:06:39 PM »
Sorry for the bad spelling. Rember I,am no pro just sharing thoughts and experiences and some basics I use. An eays way to help follow would be use the stock nuber as a base line and then do a miuns for reduction and a plus for additions. This will help keep track of change in PLAN. Look over the base and other numbers I posted and devise a plus and minus system that makes since to you. You can log these in a speed sjheet and develope a data base and making crafts and charts for comparison.

Back to discussion.Lets see I left off at PSI the third thing.

Recap: Minus one  in AREA,and plus three in RPM and STROKE at zero. Now a plus one in PSI( you can plus 2 or 3 just change by 10 psi per plus).

Since I have decreased displacment effcting port area and a weaker carb single the load on piston is less and an ACTION in cylinder pressure is required to recover loss of torgue( Reaction) from decrease in displacment). A increase (plus in PSI) increases power curve and a more effective power stroke( power stroke being RPM) Yes a longer power duration between crank rotation centers which effects intake speed.

I hope this is starting to make since. See how a psi action offset the reaction of area increasing BHP at speed due to longer power stroke.

An example is you budy will leave you out the hole but when your on the pipe say good by. The discussion was on trial ridding not hill climb or drage racing. See the corlation now take you chart and lable it speed/distance. Did you lable you chart top to bottom

P    +1
L      0
A    -1
N   +3

Next I will post up math based on base line verses Speed/ distance plan.

Questins ask away, I will do my best to ansawwer. My t.v show  on.

Adnoh

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Fl 350 stroker project
« Reply #6 on: November 15, 2008, 08:09:21 AM »
Hers the math.

I will post up next step. Piston speed , piston accerlation, cr, port timing area and speed and carb size  and single pressure relate to density for discussion as well as what changes will need to take place to achieve results based on after market parts avalible. Ya theres a lot to consider and do to make it work. You just dont go ok put it in and see what happenes. Well you could but youll be chasing things unless your lucky out of the gate.

 I wolud like to add this for you to think about before next post

#1 Bemp does not have much to do with accual cylinder pressures

#2 Torgue is a function of Displacment (A) and BEMP (P)

#3 Stroke in limted by crank speed and the force incured on related parts ( mechinal limits).

stix

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« Reply #7 on: November 15, 2008, 07:29:58 PM »
Adnoh wrote: P L A N = BHP. BHP is brake horsepower. The mathmatical output in a perfect world. Do not confuse this HP horsepower. P=BEMP or brake means effiective pressure, PSI. Do not confuse this with CR compresson ratio. L=piston stroke in feet. A=are of one piston in square inches. Do not confuse this with a single plain dimension like measuring across the piston. This is a two plain dimension( r-squared, two lines). N=the number of power strokes( rpm ( revalotions per minute) math= P x L x A x N diveded by 33,000 ( 33,000 = the constant for one horsepower)

Adnoh

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Fl 350 stroker project
« Reply #8 on: November 16, 2008, 06:45:19 AM »
Sound like stix is doing some math. He p.m. me for clarafaction and shared with the board to clear up the #,s .

After looking over the  #1 #2 #3. I will work on #3 first CM= means piston speed. Lets find out how much the crank train can hadle using the theroy #s for speed and distance.

Lets discuss waht effect his may have. According to "N" of our P L A N , I have changed the rpm effecting CM. There is others that have effect but lets stay with the #,s in the plan.

Rember that the piston accelerates and slams to a stop twice for every 360 deg of revolution. This means that a piston accerate to around 100 + miles per hour than stops and and starts again. Talk about G- forces the math there is way above my head.

The inerta forces on parts are extreem. The bearings on the crank, rod and piston pin must hadle these loads. This is to say every time you increas rpm you increase these forces to which the crank train must handle.

Can you take this to far, Yes and "CM" will help set limits to which will safly allow the crank train to survive. Theres is others but lets leave them out for now. A good rule to follow is 4000 feet per/min. This comes from smart peorple with education.

As you increase bore "L" the loading forces are greater. Not just because the piston is heaver but every thing else related. Take some weight off of the larger piston does help however the increse of related force like ring pressure restance and area is still there. A decresae in "P" BEMP will help but not enough.

 I will not get into resance force( Pressure waves) untill much later these change due to change in mass( removing weight). Ever wonder why a 350 sound diff from a 400. You are hearing the resanation forces. This is why I listen very close to ones machine It will tell you alot about one machine and whats in it and the preformance levle as long as the basic rules are followed. If not it will sound nice but preformace will suffer.

Since I decreased bore the CM will allow the a greater increase in "N"  RPM or power strokes. Rember action/reaction,the issue now will become port timmming and combustion chamber size and shape to make it work and be effective at "N" putting it in the power range of the porting ,cumbustion chamber and related bolt up parts.

I will post chart showing the effect theroy has on CM to make sure its with in limits and I will discuss piston accerlation next and the effects they have on rings.

Adnoh

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Fl 350 stroker project
« Reply #9 on: November 16, 2008, 06:52:24 AM »
OOPS! 4000 feet per miniute not second. Per scond thats rocket sicence. Man would I be lost in space. Sorry every one.

Piston speed      max 4000 ft per min

stix

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« Reply #10 on: November 16, 2008, 01:01:32 PM »
Im following so far,4000ft per second?, bet one could not only chase but pass Draks and leave a trail of glass from the melting sand behind. The last chart you showed PSI at 140 with 8500 RPM/377 piston speed, is that a misprint, maybe should be 160?, just double checking because I didnt find any changing variable to get a higher RPM and piston speed or maybe Im just a little lost. O and here are your measurements. Wiseco 81mm piston ring thickness: 1.16mm(.045)

Adnoh

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« Reply #11 on: November 16, 2008, 01:29:29 PM »
colum #1 is stock #2 is the theroy using discussion #1 + and _ plan. Colum #3 is max piston spped at 140 BEMP showeing how rpm can be gained. CVT top speed is limited by RPM. More rpm more top speed as long as you as your power stroke/torgue curve does fall off or it just make noise while your buddy is passing ya with a depper thoater sound. If Colum #3 was increased to 170 bemp than it would past max piston speed and reduce reliabilty.

Weed

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« Reply #12 on: November 20, 2008, 05:25:25 PM »
You really know your stuff.  

The experiment I am attempting......is not going very well so this project is on hold for the time being.  I am trying to design a bridgeless sleeve to in stall into a cylinder.

So if you know the stock port timing you could help me calculate the potential output.

Weed...

Adnoh

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Fl 350 stroker project
« Reply #13 on: November 21, 2008, 08:31:35 PM »
I,am working on the port timing math based on #'s given to me. I was wating on a motor to degree. I can get close with out however the area in time and flow rate related to Cr will need to be done with a degree wheel to be accurate. I can calculate your area in time if you give me your new width and height. Ive beeen busy dialing in my new shocks. Ill do your #s next before I do Cm work on theroy. Waht type of issues you having Mabey I'll be able to give it some thought. I know lloking at the port its does not look oval enogh as is to support bridge removal. Ask La sleve if they can send you a sleave with the exhaust not cut.

Adnoh

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Fl 350 stroker project
« Reply #14 on: November 21, 2008, 09:21:52 PM »
Good news first. pelimb #s show 61.777 BHP at 160psi  cranking pressure with you rpm at 7300. The bad news you will only be able to spin it 7700 rpm you piston speed is at 3975.202.  This is based on a CR of 6.5 to 1  You would most likly want to reduce you PSI to 150 and  and set up your clutches for 7300 reducing your piston speed to 3768.698 making it more reliable and keeping it in its power band. This will help with no laod spin allowing blow by cases to get past rings. This also may require raising the exhaust port 3  to 4 mm and reducing Cr and increasing your head chamber from 21 cc's to around 30 to 34 cc's or your thermal load on piston will be bad and could flash over the psiton pin taking out small end bearing on rod. This will also increase power stoke strenght. One other thing it will help is the pressure on rings reducing fiction under pressure this is referd to ring stictation. This is common mistake made with bore incresae. Most lighten the big piston but fail to calculate for this. Let me know what type and thickness of rings you will be using. since we increased PSI a reductin in Cr must offset it for reduced thermal load or you'll have a lazy motor due to washing the cylinder to keep it cool. I take it you want to run pump gas This it what I based it on.  Read this over and give some feed back for discussion. I,am not real up on 350 clutch set up. But with that much torgue you should upshfit a lot quicker and a lower engine speed wont hurt nothing. I say give the clucth all it can handle and let the torgue( big bore ) run it out. The #'s I have on ex port width cant be right its almot 63 mm. Measure your up and let me know Thanks.