331 daily driver

[Jay5_o]

Thanks for the information. I will keep this in mind when building up my own motor.
stroker kits are only like $900us , thats a good deal considering you get rods, pistons,
crank, and bearings. I'd probably go stroker too since the spinning mass is lighter.

 

[stang2841]

yeah stroker it is i only want a mild build , mild cam , mild everything. daily street driven, good parts, no skipping on anything. I want about 310 crank using just a TF intake or a cobra and windsor heads and a full exhaust. ill probably get more tho

oh yeah 3.73 gears

 

[StormWatch]

Mr. Yount,

What I meant by a 347 be faster than a 357W, is if the 347 was at 400 rwhp and the 357W was at 400 rwhp. The 347 would most likley get there first. Quicker acceleration of the rotating mass in the 347. The quicker acceleration of the lighter parts helps the 347 rev faster.

The short 5.4 rod compared to the 1/2 inch loger 351W rods will rev faster, period. This page will help me explain this theory better, although you may have seen it before. http://victorylibrary.com/mopar/rod-tech.htm

The block is a concern, but most guys will be lucky to make 450-475 N/A HP at the flywheel.

Attention to detail, like a good 5 angle valve job, titanium retainers/valves, file fit rings, rod journals cut to 2.10" or 2.00", CNC machine work, is how some guys can make 75 more horspower than you with similars looking parts.

Take your typical GT40P headed street car with a Cobra, Performer or similar intake, stock cam and exhaust work. Maybe it'll make 300 rwhp if your good. Now Ed Curtis can get lots more than that out of the same parts.

How ?

Attention to detail, most likely he'll run a lightweight 255 crank (the one with the hollow rod journals), lightened polished rods, custom light weight pistons, degreed cam, short tool steel pins that are say .866" in diam) all balanced to 28OZ. Were as most guys will use their high milage stock 5.0 HO shortblocks or an Explorer longblock plucked from the salvage yard.

SW

 

[Michael Yount]

StormWatch - you can call me Michael; Mr. Yount is my dad.

I think it's likely just semantics - my point is simply that a 400 crank HP engine is a 400 crank HP engine. Measuring at the crank or the rear wheels already takes any rotating mass losses into account. Now, you may have to spend more money/money in different areas to obtain the same output from the two different starting points - i.e. you might have to have a bit more flow, or spin things a bit higher to make up for the mass difference - but 400 at the crank out of either engine is easily attainable. All the factors you're speaking of (I've been using the victorylibrary link you posted as a reference for others for a couple of years now) come into play if you're talking about building a super high-power motor that's more on the edge, or if you need to get the absolute most out of a given package in a tightly contested rules-restricted class. We're not talking about that here. We're talking about building a reasonably mild street motor from 302-source or a 351-source. I still maintain it pretty much comes down to what you want, or what pieces you already have that you want to re-use.

 

[StormWatch]

Micheal ,

HP is HP, but the engine that can rev faster through the power band will get to the end first.

How about this ?

Back in the mid '90s for circle track use, the 302 was used with a 3.48 stroke crank and checked in at 350ci with a 4" bore or a 355 with a 4.030 bore. This setup dominated the circle track ranks so much that it was banned from competition.

If HP is just HP. Why did this combo dominate the General's 350 ?

SW

 

[Michael Yount]

A million other reasons why one could've dominated another - much more likely to do with heads, breathing, cams, etc. - I don't know the series/era - but if the Ford's were truly dominating, it was because they were making more power than the General - or making it in a way that the racers could more effectively utilize it. That power may have come from the advantages of lower rotating mass - but that's not the whole story. The rest of the story is that the competitor couldn't, by the rules, do anything to offset that advantage. Apples and oranges example compared to this fellow's dilemma. He has no limitations that keep him from building equivalent powered engines.

HP is HP - if it's the same, they will do the same amount of work at the same rate - that's the definition of HP. All else equal, if one will get through the power band more quickly, then it's making more power. But our starting assumption is that they're equal in output - which means any rotating mass advantage is already accounted for. As I said before - it's semantics.

 

[StormWatch]

Well, lets agree to disagree on this topic.

But on one final thought, pick up a 5 lb bag of potatoes and swing it in a circle. Now try the same with a 25 lb bag.

The 5 lb bag will get to speed faster than the 25 lb bag and will have less stress put on what holds it together.

 

[Michael Yount]

I'm not questioning that it takes more umph to accelerate the larger rotating mass - not sure how you concluded I was. Your attempt at analogy falls short. The 5 lb. bag will only get to speed faster if you use the same force to try to accelerate the two. The 25 lb. bag can reach the same speed in the same time - it'll just take more force to do it.

That's the point -- if you measure HP at the crank - the rotating losses have already been lost. If they're both putting out 300 at the crank, they'll accelerate an equal mass of car at the same rate. Now, the 351 may take more air/fuel to move it's potatoes.....but that's a different issue.

And, like you before, I'm ready to let it go.

 

[hllon4whls]

Storm, a build 347 with a lightweight crank, rods and pistons cannot be compared to a stock bottomed 351 with a similar cam and similar heads. It seems that is where you are concentrating your thoughs. If you build a 351 straight up with no overbore and light weight, it would be right on top of a similarily built 347. The 4 cubic inches are not going to make that much difference. Then the only difference you have is the difference in weight of the blocks. The 347 will be approximately 50 or so lbs lighter than a 351. This would be worth approx .05 seconds in the quarter mile.
We all know that .05 seconds is an eternity in drag racing.
Add in the 10 extra hp (over 2 per cubic inch!) from the 4 cubes and you have virtually identical ET's.

 

[StormWatch]

Engine building, camshaft selection, and torque converter selection has many, many different aproaches.

By all means, go with whatever your comfortable with.

SW

 

[QDRHRSE]

I know I'm late but I want to add a couple of things. Strokers are great for making power but are not very good for daily driving. When you stroke an engine you are changing the dynamics of the engine internally. A 302 is a 302 for a reason. A stroked motor will not have the longevity of a stock sized motor because parts wear faster due to a lot of factors (too many to discuss- different kits, different problems). I don't see the point in building a daily driver that will wear out faster....just my opinion. As for the drivability of a stroker thats another story. You can set them up to run like a stocker. If you want a driver, I would build a stronger standard bottom end with a main girdle, good rod and crank bolts, and then use a power adder.

 

[StormWatch]

QDRHRSE,

Broad statements like "A stroked motor will not have the longevity of a stock sized motor because parts wear faster due to a lot of factors " is flawed, as the 302 is merely a stroked 289. A 331 has basicaly the same rod ratio as stock. Why would this wear faster ?

Also "Down Under" in Australia you could buy a new Ford Falcon with a 342 ( stock 4.00 bore with a 3.4 crank ) already installed from the dealer.Yeah it was a limited edition and could not be bought here in the states. Although that car now comes with a 5.4 mod motor. In the states only the trucks get the 5.4.

SW

 

[Michael Yount]

And before the 289 were the 260 and the 221....

Built well with quality components, any of those combinations can work just fine with long term reliability. None of them have as aggressive a rod/stroke ratio as some of the big block Chevys - and they've held up fine over the years.

 

[QDRHRSE]

Storm,

You make a lot of good/valid points but the fact remains that after 302 cubes cylinder wall wear is increased dramatically as is piston wear. I didn't get into specifics because there are so many different ways to to go about making more inches that it is hard to not generalize. I never heard about the Austrailian stroker but there's a reason it never went into anything out here.

Mike- Ford did indeed keep increasing the size of their small block and had to revise their connecting rods each time. In the 60's they had a lot of advances in metalurgy and were able to cast blocks with thinner cylinder walls and cast stonger cranks and rods. They finally got to a point were the had oiling and wear issues and stopped. Then came the 351. Is this not true and/or logical?

 

[Michael Yount]

While it may be true and logical, I suspect it may miss the point. I believe what we may be talking about is an engine that, when well cared for, might go 500,000 miles vs. one that will go 200,000 miles -- and none of us are likely gonna put more than 75,000 miles on one anyway. At which point I conclude - what difference does it make?

 

[StormWatch]

The reason why the 342 (347) was not available in the state was the damn federal emissions spec. Offset pin holes in the piston will negate some of the wear in the bores. You can also you can run a 5.4 rod with a 3.4 stroke crank and NOT have the pin in the oilring. You simply squeeze the ring grooves up and run a Ford mod motor piston pin. The pin diameter goes from .927 to .866. With this trick and an offset pin hole around .050-.060, it will not cause excessive wear or any oil consumption possibilties.

I've mentioned before, alot of high end reliability goes the way of cheapness. Like who would spend $700 or more for a set of custom pistons for a reliable 100K+ mile 347 (llike above) when they can get the whole kit for $999 shipped from XYZ Corp ?
-
Did you know that Ford almost built the 351W with the popular 3.85 stroke crank before the feds shut down the project?

I mean it uses a stock length 351W rod and a 302 piston. Parts that Ford already had plenty of in the parts bin.

Suprised they came out with this crank first ?

 

[QDRHRSE]

Mike you're right except that I do drive that much- I probably drive 75k a year or close to it. When I build something as a driver I, personally, need it to last. As for Storm you've got me. I am a cheap Jew (I am jewish- I can say that) and that's exactly why I wouldn't buy a stroker kit. A good stroker kit costs so much that I'd rather get a blower, other power adder, or even spend money elsewhere. I'm not even kidding. You are 100% right on with your example of a $995 stroker kit...I think that they go for less even. I 've seen so many posts that say "Just bought Stroker kit with Cast crank. Will it handle XXX hp?"

 

[StormWatch]

Australia also had a 302C engine, this was a 9.2 deck with a 3.00 stroke crank. Basically a destroked 351C that was available in the Falcons. Go here to check it out http://p080.ezboard.com/ffordsperformancefalconsforumfrm18

Don't get what I said about the $999 strokers as all bad. Some of the better kits come with SRP pistons (made by Je pistons), Je plasma-moly rings, 5.4 rods and a cast crank. A cast crank stroker will outlive the factory block in most cases. These kits will make good power, but just won't last as long.

For someone who only drives 20 miles a day it will take almost 15 years to get to 100K miles.

OTOH...You don't build a stroker and not beat on it, if it does not break you'll get bored and put a bigger one in next time. I mean this is a sickness not a hobby.

"Obsession is the word the lazy use to describe the dedicated."

SW

 

[StormWatch]

I'm not questioning that it takes more umph to accelerate the larger rotating mass - not sure how you concluded I was. Your attempt at analogy falls short. The 5 lb. bag will only get to speed faster if you use the same force to try to accelerate the two. The 25 lb. bag can reach the same speed in the same time - it'll just take more force to do it.

What is 'force' in the automotive world?

Could it be torque...?

If so, you just answered my question about lightweight internals getting to RPM faster. If rotating weight does not matter, Why do performance engine builders go to great lengths to get the lightest rotating assembly?

It's all about the 'are under the curve'.

 

[jwzg]

Sorry to ressurect this thread Mike, but I was doing stroker research and thought I'd finish it off. I know that last question wasn't addressed to me, but I'll answer it anyhow. That force is not torque. That "force" is the explosion created when fuel is mixed with air and a spark is thrown into the mix. After that force is applied to a piston connected to a rod turning the crankshaft, the result is torque. That 351 may have to have bigger explosions to produce that same force, but if it does, you will have the same result at the flywheel. Rotating mass is scrutinized because air and fuel are finite in most racing classes.