Ideal 351W Build..?? [Archive] - PoMoFoRacing Forums

blk95gt

08-22-2004, 12:38 PM

That does sound like a nice piece, but the cam does sound a bit radical for Harris county emissions...but if that combo has been built and passed emissions, that would be a killer street combo. I was actually thinking of a 3.75 stroke
6.200 rod
TFS-R intake
42lbs. injectors
75mm throttle body
80mm MAS
.530, .540 224,230 @ .050 114 LSA on 112 intake centerline (cam motion)
9.5 to 1
ported TW with 2.05intake, 1.65 exhaudt
shorty headers, full exhaust with cats
5-speed with 3.55's
This is just my opinion...woulod like more input

LilRedLX

08-22-2004, 02:31 PM

those are about the same setups........i think the smaller induction / valve size keeps the velocity up.........

as far as the cam not passing emissions...........the only thing that MIGHT not do the trick is the 112 seperation. If you were worried about it goto the 114. The worst case senerio is that the 114 would love the dope and you'll end up owning me a BIG favor. I bet you'd be damn close.

Besides.......I have a knack for making close cars pass. :ity:

Dougstang

08-22-2004, 03:03 PM

I've thought of something like this also. I had figured that a larger displacement engine would have a better chance of passsing emissions than a smaller one at the same power levels. If you figure a 393 making 430hp is right about 1.1 hp per cube. A 302 making 430hp is 1.42 hp per cube. I know, I know the 393 weighs more. (all et's are from the ET calculator on the front page of pomoforacing) In my car the 430hp at my current (302) weight would be an 11.60. Add 150lbs for the 351 and the ET drops to 11.77, but if you can get it up to 450 the et comes back down to 11.60. 20 more hp shouldn't be that hard to find. The 1st gen lighting's had roller 351's that pass emissions fine. If the emissions are measured in parts per million, then adding cubes shouldn't increase emissions levels.

It seems like the smaller, higher hp per cube engine would be a higher revving more radical engine that wouldn't be running in it's efficient rpm range during street driving. The big cube engine at 1.1hp/cube could be a fairly smooth running well mannered regular pump gas engine (think 332 hp 302).

Just my thoughts, Shoot em down if I'm wrong.

Btw, this is all N/A, power adders change everything.

Doug

Avery wanted me to add this smiley:jaw:

blk95gt

08-22-2004, 03:14 PM

I read a post, I think, in the corral.net that because Ford put the 351 in the 95 mustang (Cobra R) that in the emisison test there was an option for 5.8 v-8 when choosing motor size for the car to be tested....If this is true hopefully that would be something in my favor since I am planning on a windsor in my car. With some more engine recipe's and a lil mo money I'll be on my way to a windsor powered stang...Has anyone heard of or dealt with Motor Machine & Supply out of Arizona, I read somewhere that they had a state of the art cam selection program...??? I know that the cam is probably gonna make or break me on the emissions, if it wasn't such a pain to change, I'd have two cams...one for emissions and the other for "playing".

LilRedLX

08-22-2004, 08:37 PM

Dude...........the cam spec I gave you is about right and would do fine. I told you that if ANYTHING was wrong with it, it would have been the 112 lobe sep. which MIGHT make the Hydrocarbons raise. By changing to a 114 instead you would lower both HC and NOX. The 114 lobe sep will also help with the dope...............not to mention if your whole combo raised the compression to the 10:1 I was speaking of. The higher compression will not hurt emissions and infact should help emissions (complete burn of the fuel). No matter what, I don't think any cam company is going to give your money back if it doesn't pass emissions with a stroker, big headed, big headed, monster motor.

When it comes time to test it, lower the fuel pressure a tad and run it super cool (floor fan and/or an ice bag on the intake).

I can help you with all of this and it can be run a few times on TEST MODE for tuning till its right. Once you have the combo figured out, you can go test it anywhere else you want anywhere in the state.

The trick to all of this is to make the burn as complete as possible, run the intake as cool as possible with the exhaust as hot as possible. Make your big time power with the dope...............WHA-LA!

mid to low 10's, on a budget, emmisions friendly (with a little help)

TxBandit

08-22-2004, 08:48 PM

Lee:
The cam you spec'd out may be right, it may not, but it is obvious that you didn't put any thought into the rest of the shortblock.

John:
For a street/strip engine the shorter stroke is the way to go. I'd use a rod shorter than 6.200 if you plan on spraying it a lot though. Nitrous motors like a short rod. What type of block are you planning to use, stock or aftermarket?

Troy

blk95gt

08-22-2004, 09:41 PM

Troy, No nitrous to be used and it probably won't get hardly any track time...just a fun "play" car for the street....my wife will probably drive it more than me...I have a stock 96 block, 6.200 rods, TFS TW heads, headers and Probe pistons (1.35 c/h flat top). The 95 needs a motor and these are the parts I have to spare, all I need is a crank and cam, i just wanted to see if anyone had a "reliable" combo....and it seems what I am hearing is just about what i want to do. But, just because I have the parts doesn't mean I have to use them....That's why I started this post was to get ideas.

Lee...thanks for your input, wasn't worried about getting money back from a cam company if it didn't pass emissions. I figured if I can get the cam close Ben could tune it to perfection.

LilRedLX

08-22-2004, 09:49 PM

Troy.............what else did I need to mention about the short block (as it purtains to emissions)?

I felt I gave a nice little combo without getting too specific.......

I guess I could get MORE specific but I don't think it will change the total package all that much.

By all means please add to what I "put together" if you think my idea is "mostly" correct.

As far as the rod being too long........WHAT?

The 6.2 rod with the 3.85 stroke (which is what I said) has about the same rod ratio as the 345ci motor I run. How much shorter of a rod would you prefer to run? Besides, there has been discussion about a long rodded motor's ability to burn more completely due to its dwell time. (you and I have spoken about this as well) This ability should help it with emissions. Besides, we are only talking about a 150 shot.

What are your thoughts?

TxBandit

08-23-2004, 09:52 AM

Lee:
I re-read the thread and never once did you mention using a 6.200 rod. You did mention building a 393 and the most common 393 stroker uses a 5.955 rod and a 302 piston with the 3.85 crank.

Ever thought about this: A short rod has more dwell time at BDC allowing for more air/fuel in. More air/fuel in = more power out.

How about the fact that a correctly shaped combustion chamber and the right amount of quench area will produce a more complete combustion process.

So, it apears to me that if you have a correctly shaped chamber and the right amount of quench area you will make more power with a shorter rod. Also, it is VERY common for a short rodded motor to make more bottom end torque which is ideal for a street motor.

In the racing world things can change a bit.

John:
I did some math based on the parts you have. I had to make some assumptions, so please correct me if I am wrong. Based on your rod/piston/deck height the numbers say that a 3.900 crank will bolt in. Based on that info I did more math and I am afraid to say that your flat top pistons will yeild quite a bit more compresion than you are shooting for. Assuming that your combustion chambers are 64cc you will have about 11.6:1 compression. If you open them up to 78cc then you'll have 10:1, but IMO this isn't a wise choice.

Put some thought into reciprocating mass too. A long stroke will make more torque, but it wont rev as quickly.

Troy

LilRedLX

08-23-2004, 10:21 AM

I suppose your right, I did not mention the 6.2, however you know I like the longer rod (our VAST conversations on the issue) and the 6.2 is what I would use. As far as the short rod spending MORE time at BDC I would have to call FOUL on such a statement. I maybe completely wrong but the longer rod should spend more time (dwell) at TDC and BDC and the 2 measurements (in degrees) should be the same.

Shaggy and I have also talked at length about this and between the 3 of us we all have slightly different oppinions and sources in which we receive our facts from.

I think the long rod 393 (3.85 - 6.2) should spend more time at dwell thus run cleaner and, with said dwell with a 114 lobe seperation would have great cyl. pressure. The long rod motor should bring less havoc on the rings as well.

Combustion chamber shape and all of that is good and all, but for a street car I would just use off the shelf stuff and not reinvent the wheel. (hard to do better than the TFS or AFR products I spoke of)

Either setup (long or short rod) will prob not make or break this deal. Both would do well. The short rod will make more low-end torque while being harder on rings while the long rod should do better with the dope and last forever.

TxBandit

08-23-2004, 10:40 AM

You are wrong sir. Dwell time IS NOT EQUAL at TDC and BDC no matter what rod length you use. It is also true that a short rod spends more time at BDC. These are facts, ask any professional engine builder.

TFS and AFR both have very good combustion chambers. However, with a little time in the hands of a GOOD head porter they can be made better. Quench is also extremely easy to get correct. So neither of these require "reinventing the wheel".

A longer rod leads to a shorter piston. A shorter piston leads to more wobble. Please explain to me how the shorter piston is an advantage when talking of wear and lifespan.

I get most of my opinions and facts from hands on experience, where do yours come from?

Troy

LilRedLX

08-23-2004, 11:52 AM

A longer rod leads to a shorter piston. A shorter piston leads to more wobble. Please explain to me how the shorter piston is an advantage when talking of wear and lifespan.

I am not saying a shorter piston is better, I am saying the long rod keeps geometry true for a longer period and less stress pushing the assembly into the cyl wall.undefined

TFS and AFR both have very good combustion chambers. However, with a little time in the hands of a GOOD head porter they can be made better. Quench is also extremely easy to get correct. So neither of these require "reinventing the wheel".

A good "poter" can do alot with a little, this everyone knows. I was just trying to keep this simple. I think you'll get a wierd look from a porter if when you goto him you ask for a chamber that will," Run emmisions friendly." I also don't want this confused with flame travel which is what I think will help with emissions. I suppose there is some to be gained from reworking the chamber, I was only coming up with a combo (as asked) that would run clean and make power.

I get most of my opinions and facts from hands on experience, where do yours come from?

I think this was a little uncalled for. But since you asked..........I have built some pretty nice motors and run some fairly good numbers. While I have NEVER built a motor to run emmisions friendly I have inspected for the last 6+ years. IN this time, I have come to understand what works and what doesn't. We have learned why NOX goes up, how this relates to CO, and what moves HC around. As I said before, either setup sould work, I think the bottom end will make SOME difference but I think the biggest deal here is the cam. Right now we are bench racing and until someone builds this thing its hard to prove one way or the other.

TxBandit

08-23-2004, 01:01 PM

Hmmm....slowly peeling back the lid on a HUGE can of worms.

Troy

I agree, it's all bench racing at this point. You keep your long rodded engine and I'll keep my short rodded engine. One day we'll meet at the track.

I should have known better than to stoop to this level, but I entered myself into this discussion anyway. My superiorority complex got the best of me.

Troy

LilRedLX

08-23-2004, 01:38 PM

I still love you Troy.......I'll just look at you wierd next time we shake hands (after reading you masturbation thread). :nuts: :hmm: :smokin:

blk95gt

08-23-2004, 06:30 PM

Hey guys i was just looking for some input on some ideas, didn't mean to open a can of worms....Like Lee said it is mainly coming down to cam selection, and as for the bottom end it will have a 3.75 stroke and 6.200 rod with a piston c/h of 1.40, which in my opinion is not that short of a piston. Hopefully will be taking the block to machine shop sometime in the next couple of weeks.

P.S. Hey Troy where did you come up with a 3.900 stroke crank??? I will be using a 3.75 stroke, if my memory serves me right it will yield 383 cu.in's with a 4.030 bore. The cam specs I was referring to came from Cam Motion, I know you like to use them, this will be my first time getting a cam from them, so I hope it makes TONS of POWER and of course hopefully passing those dang emissions!!!!!

Lee, when the motor runs and gets tuned I'll be heading your way to see if it hopefully passes emissions...

TxBandit

08-23-2004, 07:01 PM

I have a stock 96 block, 6.200 rods, TFS TW heads, headers and Probe pistons (1.35 c/h flat top)

9.5-6.2-1.35=1.95

1.95x2=3.900

Troy

Thoroughbred

08-24-2004, 01:00 PM

A longer rod leads to a shorter piston. A shorter piston leads to more wobble. Troy
What is this wobble that you speak of? Inquiring young minds are curious and want to learn. :darkbeer:

TxBandit

08-24-2004, 02:02 PM

Imagine trying to push a tuna can through a tube with a stick. Now imagine trying to push a 3lb coffe can through a tube with a stick. The can that is taller will be more stable, less prone to "wobble" back and forth. You will gain some friction but this is negligible on an engine that operates in a lower rpm range.

Troy

LilRedLX

08-24-2004, 04:25 PM

however, alot of pistons reguardless or pin placement and ring placement, are the same size or close to it. (speaking of the same application only with the same manufacturer)

I would be suprised to see a large piston size difference between the 5.9 rod and the 6.2 rod even though the pin placement will differ dramaticly. With the naked eye, anyone could tell you which is which.......however, if there were no pin hole machined and the two were side by side, I bet you it would not be so obvious.

And if wobble were so important, why would you not try to keep the rod ratio high and keep the geometry parallel with the cylinder as much as possible? There has got to be alot more side load brought about by irregular geometery ( short rod big stroke) then by a "tuna can" piston.

I have not gone and "researched this" but would be interested to see 2 x 393 kits side by side. One with the 6.2 rod and one with a 5.9 rod. Now, measure the skirt to piston top height. Is there any difference at all?

Lastly, with all of that in mind, which is more stable..........pushing up on a piece from near its bottom or pushing up on the same piece from its middle? From the middle would make more sence and seem more stable and balanced. ( at a cost of oil control and ring spacing )

Just food for thought, and don't see any harm in questioning the point. Remember, if everyone took things for face value and never kept questioning, the world would still be flat!

blk95gt

08-24-2004, 07:49 PM

Boy, this thread went farther than what I thought.....I was hoping for more engine combos, but ended up with the long and short of rods. I do kinda favor the "long rod" theory of getting the geometry of the motor correct, but quite a few big blocks and race motors do have a short rod, maybe a short rod is good for low end torque and heavy nitrous usage, but I would like to assume that the longer rodded motor would have a better chance in passing emissions, just my opinion. I am almost tempted to just put a plain jane 351 in the car, but my "gearhead" roots won't let me do it....Even if a short rod motor may be better for the track, I am not too concerned about getting every little once of power the motor has to offer as long as it has a good chance of being Harris County "street legal". We can discuss another 351w build-up for my 70 Mustang as soon as I am done with this one.

LilRedLX

08-24-2004, 08:25 PM

just for sh1ts and g1ggles (because Shaggy, Troy and I have discussed this NUMEROUS times)............go pick up any mag where a winning racer tells about his / her combo and do the math on their rod ratio and let me know who is running a set up with a ration below 1.6. Not saying that their aren't some doing it...............just interested in what you'll find.

Cuz if EVERYONE is going with the short rod theory, the 383's would be owning the day, but it seems to me that the serious cars seem to do well with the DESTROKERS like the 377.

I will do some more homeowrk on this...........I have been busy doing some other stuff right now.

TxBandit

08-24-2004, 08:43 PM

I'd be willing to bet that 9 out of 10 of those winning racers are lying about their engine combos. Do you really think they want everyone else to know what their combo is? I'd go even further and bet that 3 out of those same 10 racers don't even know the geometry of their shortblock.

More times than not, in the racing world, the engine builder will start the whole process by deciding on what cubic inch the motor will be. This may be at the customers request or by the rules where the racer wants to run. At this point the bore and stroke will be determined. From there the engine builder will normally design the piston as to what he thinks is best for the particular application. The rod is typically last, it just connects the crank and the piston. I've talked to quite a few different professional engine builders who use this approach.

Street engines are different, they have to live a long time and more times than not they will consist of off the shelf parts and need to be cost efficient. Whatever motor you decide to build will run well. When you get to the point that you want an all out racing engine you have to forget about off the shelf parts and be prepared to spend some cash.

Troy

LilRedLX

08-24-2004, 10:14 PM

Whatever motor you decide to build will run well. When you get to the point that you want an all out racing engine you have to forget about off the shelf parts and be prepared to spend some cash.

A-man to that brother!

nintylx

08-24-2004, 10:23 PM

9.5-6.250-1.375= 1.875

1.875X2=3.750

NintyLx

LilRedLX

08-24-2004, 10:36 PM

Troy could be right about ALL of that. In fact he prob. is in fact totally right. In our long conversations I can honestly say he is well versed in the engine building world and I really enjoy everytime we have talked.

I have been raised with "old" principles and taught things differently. All of the best running motors, from the days of old, used a very simple method of big bore, short stroke with a long rod.

These motors include the rip roaring Mopar 340, Ford's 427, and the GM 302.

There were some motors that used a huge stroke with short rods but all in all the legends were made with the theory I was raised with.

I also remember a time when I was younger that the GM guys would say, "Yeah, we're building a 355 long rod car for next season." or even when this 5-litre craze took over in the late 80's and early 90's when rules would make you run 306ci or less and guys would run the long rod in the 302.

While I understand the arguement against this long rod stuff (after talking with Troy) but I have also spent the last 15yrs listening to why you should believe it. Its prob going to take alot more explaining and a few times for me to see it in order to believe it............maybe I'm hard headed or maybe its just hard for me to undo 15yrs of being taught something different.

I can't speak for Kasse or Sheridan (big name - big time race engine builders) but I do know a few locals that have been racing and building for years and they ALL believe in the long rod. ie. Mr Whatley from Whatley Machine Shop, Clete who ownes JK Machine and builds the motors for the NASCAR school up in Dallas, and Richard Pitre aka Popeye who has built a few fast cars here and there but does really nice fab work at ASP for Lee Cooper.

I have never asked Conrad, but know they have built some of the fastest cars around SW Texas, but I would be interested in what they had to say about the matter.

As of now, I will agree with Troy, use an off the shelf kit and don't get fancy-shmancy.

Now then........when are we going to be invited over to drink your beer and watch you put this thing together? :drunks:

nintylx

08-24-2004, 10:52 PM

LilRedLX

08-24-2004, 11:05 PM

ninty, I think you missed his point then. With the increased piston speed that you pick up with the short rod makes more low RPM torque so it makes for a better street car where you can use the power all the time.

Troy, I don't believe, is saying that a short rod helps life at high RPM and in fact I think he said in this very thread thats it not recommended for high RPM motors.

Troy even will tell you that he believes in low recipicating weight and talked me out of building a 408. So please don't think he rec. you building a 1.5 ratio motor and spinning that thing to 7500+ on a daily basis cuz I don't think he's saleing that idea.

TxBandit

08-25-2004, 09:24 AM

On a short rod motor the dwell at TDC is so short that crank, piston, piston pin and rod loads are increased high enough to make high RPM operation temporary! I like to use all the tach hell I paid $$$ for it it! :evil:

The dwell is in fact so short that it allows you to run much more ignition timing due to the reduced chances of detonation. We all know that if you are able to run more timing you have the chance to make more power. I'd rather have more power at lower RPM and have my motor last a little longer.

Also, even with the increased friction in a short rodded engine, you will have less friction overall based on the fact that the motor isn't cycling as fast.
:)

Troy

TxBandit

08-25-2004, 09:54 AM

Oh yeah, when your long rodded junk runs a good number let me know :fu: :D

Tyro

blk95gt

08-25-2004, 10:56 AM

Gosh darn Troy, why it gotta be "long rodded junk" ???? All I wanted was a windsor powered car :ashamed: .... as for "good numbers", what would you consider good numbers coming from a N/A car that is "fully" street legal (legally passed emissions), ac, power everything, 20mpg, pump gas, sit in summer Houston traffic without overheating and cruise to another state and back with no problem, just curious.

Lee, when the motor is done and ready to go in I'll invite ya'll for a "Driveway Party" for the install and initial fire-up, hopefully when the weather cools down a little.

TxBandit

08-25-2004, 11:05 AM

That was aimed at Alan.

I'd think that you could put 375-400 to the ground, I'm not too sure about getting 20 mpg though!!

Troy

nintylx

08-25-2004, 05:09 PM

Yea yea! I have worn out more motors on the track than you! :fu:

nintylx

08-25-2004, 05:15 PM

;)!

289-302 based strokers (4.030" bore - 0.030" over stock)
Displacement 289 302 315 331 347 355
Rod Length 5.155" 5.090" 5.205" 5.400" 5.400" 5.205"
Stroke 2.870" 3.000" 3.076" 3.250" 3.400" 3.500"
Rod Ratio 1.796:1 1.696:1 1.692:1 1.662:1 1.588:1 1.487:1

351W based strokers (4.030" bore - 0.030" over stock)
Displacement Stock
351W 383 393 408 418 426
Rod Length 5.956" 6.250" 5.956" 6.125" 6.200" 6.125"
Stroke 3.500" 3.750" 3.850" 4.000" 4.100" 4.170"
Rod Ratio 1.702:1 1.667:1 1.547:1 1.531:1 1.512:1 1.469:1

nintylx

08-25-2004, 05:16 PM

The dwell is in fact so short that it allows you to run much more ignition timing due to the reduced chances of detonation. We all know that if you are able to run more timing you have the chance to make more power. I'd rather have more power at lower RPM and have my motor last a little longer.

:)

Troy

Ignition timing on most any engine should be 34 degrees(give or take 1 or 2) total with full mechanical advance dialed in. More advance may feel better off the line but the engine lays down as the combustion chamber components come up to temperature. At the drag strip set timing for maximum MPH not best ET. Too much spark advance will shorten the life of any performance engine, sometimes drastically. :rant:

NintyLx

LilRedLX

08-25-2004, 07:10 PM

as for "good numbers", what would you consider good numbers coming from a N/A car that is "fully" street legal

what the hell are you talking about NA??????

Ya might as well spray the thing.........if its doing 400 to the ground, imagine with the dope! :ity:

blk95gt

08-25-2004, 07:51 PM

There's nothing wrong with N/A, coming from an old street racer...I might say it's N/A, but there's alway something up the sleeve....kind of like an insurance policy.....As for MPG at 20 why not...just keep the foot out of it :ity: As for the numbers, I would be happy with 350 to the ground, that's plenty to put someone in there place if they don't suspect it...

Hey Troy, we need to set a date and go hang out with Lee one Friday night and just B.S. This internet stuff sure does take a long time to get a point across....

gt350mustang

08-25-2004, 09:36 PM

i will throw out a combo for you. my old 351 was :
less than 9 to 1 comp. box stock tfs tw heads , small cam, gt40 intake, blower
it made 515 rw and recorded 18 mpg several times. i am pretty sure the motor was an easy 400 hp piece. this was pump gas on a basic tune. that motor, setup for n/a, could have done 450 hp pretty easily.

1slow83gt

08-25-2004, 09:55 PM

What you need to do is get off the internet and lets but the damn thing together :eeek:
So are you ready to put my clutch in? :wavey:

blk95gt

08-25-2004, 11:32 PM

"1slow83gt", I told you I could put the clutch in with one hand tied behind my back.....make a deal with ya, I'll do the clutch and you do the windsor swap....By the way you told me we could do the swap at your crib and you were gonna supply all the beer and B-B-Q for everyone that wanted to come over and hang out to watch you work...!!! So Mr."1slow83gt" are you ready to deal with all us "POMOFO's" at your house while we drink, eat and watch you work, now that we have figured out what motor combo I will try and put together ????

blk95gt

08-25-2004, 11:40 PM

Troy, you never got back to me about hanging with Lee and the rest of the POMOFO's, or do you just wanna wait till I get this "long rodded junk" together and ready for install at 1slow83gt's place?????

blk95gt

08-25-2004, 11:43 PM

Ok, Ok, it's late and I have been drinking....what did we decide....long rod or short rod????? :retard:

TxBandit

08-26-2004, 12:57 AM

Ignition timing on most any engine should be 34 degrees(give or take 1 or 2) total with full mechanical advance dialed in.

I know that you are more intelligent than this, so I will just act like you never said that.

Troy

Saleen91

08-26-2004, 07:04 AM

damn, not to whore this post, but I just realized both blk95gt and 1slow83gt are in my neck of the woods. :)

LilRedLX

08-26-2004, 10:09 AM

Blk..........I can tell you what we decided..........we decided that all you need to do is find an affordable piece that you like and put it in the car because they all will do well. I like the long rod Troy likes the short but both do well but do somethings a little different.

Bottom end torque will come quick with the short rod while I think a more complete burn will happen with a long rod with the capability for more RPM.

Either is fine with us (not trying to speak for Troy). Either way is not the end of the world as Troy and I would lead you to believe.

I would still like to see you have a 114 lobe seperation with a cam that leans on the exhaust side and would like to see you AT LEAST use a small 100 shot if not the 150 shot. Its cheap and easy and all of a sudden you conservative 350 - 400 hp street car wakes up BIG TIME and really puts out some good numbers.

Best of luck, and we can get together any time you like.....its Troy that hard to hold down.........he's either on his way to the track or on his way back. Ya gotta love that!