Oversized Fit Pistons

[Steve Bamford]

I agree with you 100% Steve that here is no "real" performance advantage in FF race. I have also listened to many racers that are not as honest with themselves and will make the excuse of their engine being down 0.7 HP as to why they are slow. These same drivers are typically the most vocal and participation will suffer as a result.

Steve, the differences in HP for all the engines going through my shop (rough count 14) in the last 5 years is 3.8 Hp. On the racetrack that is huge! There are a lot of Kents that have less that that by 4 or 5 HP usually because they have a very bad head. I am sure the very best that Jay has ever done has more, but I have never seen one or the dyno sheet from it. Saying that adding one more HP (which is a guess and is a little less than 1%) will make no difference in a battle between two equally prepared and driven cars makes me laugh.

I do not hate Hondas, I simply believe that they should have their own class, and left Formula Ford aone.

Roland you don’t have to take word as laughable, how about someone who also has lots of seat time in FF as in Joel with his comments listed above.

Can I ask you something on the Kent engines? You menationed 3.8 then a lot that have 4 - 5 less then that. Is the average difference 3.8? I also assume the numbers are based on after the engine has been worked on & is ready to go back to the client. If the numbers are that far off how bad are they when they are sent in for rebuild? Are they 8-10 hp off when they come in for rebuild? I have no idea, just asking to try to be more educated.

[stonebridge20]

I think the funny thing is that the oversize pistons are being marketed as a "cost savings" (where have I heard that before?) but the cost of the pistons, rings, bore job and hone cost isn't advertised in the sales brochure.

A new block is quoted at $800. Is it actually "cheaper" to go oversize?

[Daryl DeArman]

Saying that adding one more HP (which is a guess and is a little less than 1%) will make no difference in a battle between two equally prepared and driven cars makes me laugh.

Daryl spending probably $10, 000 to $15000 to convert a Ford to a Honda doesn't seem to make a lot of sense for most people.

I do not hate Hondas, I simply believe that they should have their own class, and left Formula Ford aone.

Show me two equally prepared and driven cars . Seriously, less than 2% of the racers can do 10 consecutive laps all within .3 of second of each other. . . which supports the point that 1 HP isn't going to be the difference maker people fear.

As to whether the conversion makes sense or not, it won't if you don't race a lot, or plan to race for very long, or simply can afford to think no farther ahead than one rebuild at a time.

To your last point, maybe Honda should have their own class, and in time, probably will. Frankly, the Kent engine builders created the demand by not allowing/lobbying for rules that would have provided more parity and better longevity. But then why would you want to sell your service 1/4th as often for a fraction of the price?

[Roland V. Johnson]

Steve, the 3.8 Hp was the total difference between the best and the worst. The majority were within 1.9 Hp. I have never had an engine dynoed before re-building, but I have had them win races the weekend before. I have a little seat time in FF myself, most of it in the years past. I do know the difference in a good engine and one that is not. The real question with this rule change is why, when there is a supply of blocks to use, introduce rule creep? Arguing about how much extra HP an unneeded rules change must make before it is allowed seems only for the favored few.

[Steve Bamford]

Steve, the 3.8 Hp was the total difference between the best and the worst. The majority were within 1.9 Hp. I have never had an engine dynoed before re-building, but I have had them win races the weekend before. I have a little seat time in FF myself, most of it in the years past. I do know the difference in a good engine and one that is not. The real question with this rule change is why, when there is a supply of blocks to use, introduce rule creep? Arguing about how much extra HP an unneeded rules change must make before it is allowed seems only for the favored few.

Thanks I figured it wouldn’t make sense to dyno before other then to detmine how off an engine was. I guess reality is when you dyno one day then do it another the results will be different anyways just due to environmental differences.

[Daryl DeArman]

I guess reality is when you dyno one day then do it another the results will be different anyways just due to environmental differences.

That's why there are correction factors to adjust HP to the same baseline. Such as: 60°F day with 0% humidity and a barometric pressure of 29.92 in-Hg.

Even back to back runs aren't going to be the same when corrected for atmospheric conditions as engine oil, water and fuel temps aren't the same. How much does the heat and humidity change in a dyno cell over the course of one pull? That would depend on how much HP the thing is making, how small the room, and how long the pull takes.

[Steve Demeter]

I think the funny thing is that the oversize pistons are being marketed as a "cost savings" (where have I heard that before?) but the cost of the pistons, rings, bore job and hone cost isn't advertised in the sales brochure.

A new block is quoted at $800. Is it actually "cheaper" to go oversize?

I don't have a dog in this fight but can you really get a race ready block for only $800?

If so I will need to send my next Pinto block to whoever is selling them for that.

[Daryl DeArman]

I have never had an engine dynoed before re-building, but I have had them win races the weekend before.

Which supports my argument that a HP or two in a FF is not the difference maker, even when things are pretty close to equal.

[Daryl DeArman]

I don't have a dog in this fight but can you really get a race ready block for only $800?

If so I will need to send my next Pinto block to whoever is selling them for that.

Must be talking about the Fit block, the new Kent block is about $1400 and isn't yet race ready.

[Roland V. Johnson]

To your last point, maybe Honda should have their own class, and in time, probably will. Frankly, the Kent engine builders created the demand by not allowing/lobbying for rules that would have provided more parity and better longevity. But then why would you want to sell your service 1/4th as often for a fraction of the price?[/QUOTE]


Daryl with the budget ( I have heard quoted) it takes to run a top line FFit do you really believe racers are going to leave 1%ish engine power behind? .........Really? That could be the difference between being behind at the end of the straight or being along side.

Trying to put the blame on the Kent engine builders is a little on the backwards side. The SCCA has been extremely reluctant to allow any changes to the Ford engine. I do know Jay Ivey quite well. I believe he has been involved in getting the pistons, crank, rods, alloy head, blocks, and many other changes which have greatly improved the longevity of the engines. That also does mean that he does not get to rebuild them as often. In my experience the Ford engines are remaining competitive and reliable 3 to 5 times as long between rebuilds. Disclaimer: We do freshen the cylinder head periodically between rebuilds.

Daryl, I have heard that many engines make the most power just before they blow up.

[alangbaker]

Daryl with the budget ( I have heard quoted) it takes to run a top line FFit do you really believe racers are going to leave 1%ish engine power behind? .........Really? That could be the difference between being behind at the end of the straight or being along side.

Trying to put the blame on the Kent engine builders is a little on the backwards side. The SCCA has been extremely reluctant to allow any changes to the Ford engine. I do know Jay Ivey quite well. I believe he has been involved in getting the pistons, crank, rods, alloy head, blocks, and many other changes which have greatly improved the longevity of the engines. That also does mean that he does not get to rebuild them as often. In my experience the Ford engines are remaining competitive and reliable 3 to 5 times as long between rebuilds. Disclaimer: We do freshen the cylinder head periodically between rebuilds.

Roland, it ISN'T 1%-ish.

It is definitely, absolutely positively no more than 0.685492921%. That is the percentage change in swept volume between a 73.065mm cylinder and a 73.315mm one. So assuming there is no reduction in breathing through the restrictor worth mentioning, 0.685492921% more horsepower is all you get. And there is likely to be some small reduction in breathing through the restrictor as my investigations into "choke point" have revealed.

And speaking to an earlier point: do you really think if the Honda hadn't come along to get Ford off their collective asses that we would have got the new Kent block? Just something to ponder.

[alangbaker]

Must be talking about the Fit block, the new Kent block is about $1400 and isn't yet race ready.

A block that didn't exist when it was decided to add the Honda Fit engine to the class.

Is there a good thread on here that tells the story behind getting the new Kent block to happen?

[stonebridge20]

I don't have a dog in this fight but can you really get a race ready block for only $800?

If so I will need to send my next Pinto block to whoever is selling them for that.

Reid stated that a new block from Honda is $800 when he checked with them, so, yes you can.

The Honda engine was "billed" as an off the shelf alternative engine to the Kent, so, yes a stock Honda block is "race ready"

[recaryob]

I asked some pretty reasonable/constructive questions previously and no one has attempted to answer them. Until someone does, I can only guess that those that support this rule, know their answers will expose how flawed the reasoning for this rule change actually is.

I have been in 2-4+ car dog fights for the lead of a race for over half the race. Multiple passes every lap. I would have given my left nut for an additional .5 hp in those situations. To say that .5 hp doesn’t ever matter is just not realistic. When it’s real close, lap after lap, it all matters.

I was talking to a long time FF engine builder today who doesn’t frequent this site, he had no idea of this rule change. I shared with him some of this conversation and he just laughed. “The front running Hondas will pull their motors immediately and put in the bigger pistons”.

P.S. For the record, sleeving a Kent correctly is about $1200. So much for the argument, Kent’s can sleeve and Hondas can’t.

[Steve Bamford]

I asked some pretty reasonable/constructive questions previously and no one has attempted to answer them. Until someone does, I can only guess that those that support this rule, know their answers will expose how flawed the reasoning for this rule change actually is.

I have been in 2-4+ car dog fights for the lead of a race for over half the race. Multiple passes every lap. I would have given my left nut for an addition .5 hp in those situations. To say that .5 hp doesn’t ever matter is just not realistic. When it’s real close, lap after lap, it all matters.

I was talking to a long time FF engine builder today who doesn’t frequent this site, he had no idea of this rule change. I shared with him some of this conversation and he just laughed. “The front running Hondas will pull their motors immediately and put in the bigger pistons”.

P.S. For the record, sleeving a Kent correctly is about $1200. So much for the argument, Kent’s can sleeve and Hondas can’t.

I cant believe half a horse power will make any difference at all. If you have any clue how to use the draft to your advantage that half a hp means nothing at all. Anyone telling you otherwise has no idea or is out right lying.

I appologize if this is being too blunt as I don’t mean to be harsh, but when people say it makes a difference they are telling an untruth. I don’t care if you allow this or not, I really don’t care at all, what bothers me is false info.

[Daryl DeArman]

Daryl with the budget ( I have heard quoted) it takes to run a top line FFit do you really believe racers are going to leave 1%ish engine power behind? .........

No sir, I don't. I don't recall debating that point.

Trying to put the blame on the Kent engine builders is a little on the backwards side. The SCCA has been extremely reluctant to allow any changes to the Ford engine. I do know Jay Ivey quite well. I believe he has been involved in getting the pistons, crank, rods, alloy head, blocks, and many other changes which have greatly improved the longevity of the engines. That also does mean that he does not get to rebuild them as often. In my experience the Ford engines are remaining competitive and reliable 3 to 5 times as long between rebuilds. Disclaimer: We do freshen the cylinder head periodically between rebuilds.

I agree that Jay has been instrumental in getting many/most/all of those parts approved. He had to if he wanted to keep his customer base. Rebuilding engines 1/3 to 1/5th as often is a better alternative than not rebuilding them at all, right? My point is that if he (and others) were proactive rather than reactive the Honda wouldn't have been accepted.

Hoosier doesn't want everybody racing on hard-ass, long living tires. They want everybody on fast, gum-ball tires that are faster than the competition, tires they can sell lots of. It's not until there is a real-threat of competition does Hoosier come up with an alternative tire everybody can live with. Sometimes, it is in-time, other times it's a little late. In my opinion, a bit sooner on the Kent front and we wouldn't be having these conversations. I know I wouldn't have sold my turd Kent if rebuilds were more cost-effective.

Daryl, I have heard that many engines make the most power just before they blow up.

I've heard that as well, but I think we may be confusing cause and effect . Engines generally lose power as the top end gets worn-out and blow up when the bottom end is worn out. They could build the engines a bit looser on the bottom and get a bit more power, but most wouldn't be happy with the end result.

[Daryl DeArman]

Roland, it ISN'T 1%-ish.

It is definitely, absolutely positively no more than 0.685492921%. That is the percentage change in swept volume between a 73.065mm cylinder and a 73.315mm one. So assuming there is no reduction in breathing through the restrictor worth mentioning, 0.685492921% more horsepower is all you get. And there is likely to be some small reduction in breathing through the restrictor as my investigations into "choke point" have revealed.

There are other factors involved. Which is why stated way back when that IF the BMEP stays the same you aren't getting more than a .7% increase in HP. However, you are getting the tiniest bump in CR if all else stays the same. You could get the tiniest increase in flow across the valves if the cylinder walls are a "sheet of paper" farther away. If the piston skirt length, ring land width and locations, and/or pin location are different you could have less friction. A difference in metallurgy and piston manufacturing quality could allow different piston to wall clearances that help as well. All those little things could add up, but I doubt very seriously we are talking about any more than 1%-ish.

[Steve Bamford]

I cant believe half a horse power will make any difference at all. If you have any clue how to use the draft to your advantage that half a hp means nothing at all. Anyone telling you otherwise has no idea or is out right lying.

I appologize if this is being too blunt as I don’t mean to be harsh, but when people say it makes a difference they are telling an untruth. I don’t care if you allow this or not, I really don’t care at all, what bothers me is false info.

Maybe I need to explain better & perhaps I need some mathematical help from some individuals with better engineering knowledge then I understand. There is drag that slows down the leading car in a pack & the car right behind is able to accelerate past & usually the car behind that one also has an even bigger advantage after the two cars ahead helping to reduce drag on the pursuant. The following cars, if driven correctly are able to pull out & pass however not able to pull away unless the leader who now is 2nd or 3rd makes a mistake some where. They are typical able to fall back in line & make the same pass the next lap or some where else on the track that offers a decent straight.

Half a hp will not make any difference on the laws of physics against the amount of drag we are talking. Hopefully someone else can write out a better reply then I have here.

[Daryl DeArman]

I have been in 2-4+ car dog fights for the lead of a race for over half the race. Multiple passes every lap. I would have given my left nut for an additional .5 hp in those situations. To say that .5 hp doesn’t ever matter is just not realistic. When it’s real close, lap after lap, it all matters.

You probably would have finished in the same position and had one less nut. That would be a real bummer.

I've raced in several different series over the years. I have had crappy motors and I've had really good motors. I've had factory team support, I've had boat anchors. I know that a great engine makes a difference. I know that when most racers are grid fodder it's all motor we want to blame. When we are winning, it's all driver. I get it. What I'm arguing is that 1% motor difference isn't making a difference in outcome at 99.99% of the SCCA races. Right now I have MX bike with a really strong motor. I'm probably not giving up much of anything to anybody. I'm going to finish my race almost DFL because I suck. All the power in the world isn't going to help, I can't use all that I have effectively.

[alangbaker]

There are other factors involved. Which is why stated way back when that IF the BMEP stays the same you aren't getting more than a .7% increase in HP. However, you are getting the tiniest bump in CR if all else stays the same. You could get the tiniest increase in flow across the valves if the cylinder walls are a "sheet of paper" farther away. If the piston skirt length, ring land width and locations, and/or pin location are different you could have less friction. A difference in metallurgy and piston manufacturing quality could allow different piston to wall clearances that help as well. All those little things could add up, but I doubt very seriously we are talking about any more than 1%-ish.

I think you're really reaching, Daryl.

As I understand it (after doing a little googling), yes: you'll bump the CR a little bit, but it's going to indeed be a tiny bump. I did find a calculator online that suggests that a change of CR from 10.4 to 10.462351781858523 (a figure from another online calculator) would result in 0.07 more horsepower for a 120hp engine. That's 0.05% (yes: 5/10000 more horsepower).

This is a production Honda replacement piston, so I don't think you're getting anything but a piston that's a tiny bit bigger (and thus heavier). I can't imagine they completely re-engineered the piston for a 0.25mm diameter change.

[recaryob]

What I'm arguing is that 1% motor difference isn't making a difference in outcome at 99.99% of the SCCA races.

I don’t know that I 100% agree with you, but accept how you are reasoning this. Obviously there are many a race in which the results wouldn’t be any different.

My argument is why would you even wish to create a 1% difference when there isn’t one now? Only so a few can save the cost of a new block (I say only a few because many to most will go straight to .010). The cost of changing blocks is already less than what we have to do with Kents. As it is now, this is already another example where the Honda is a savings.

What is the gap between a great Honda and not so great? 2 hp? Is 2hp the parity window or less or more? So now you propose that the parity window increase from 2 hp to 2.5hp? (Decreasing parity by 25%) For some to save the cost of a already relatively inexpensive block.

(I don’t know the current difference between a good and bad Honda, so someone please chime in)

i just don’t buy this arguement, to the point that it starts to stink up the room

[reidhazelton]

Hoosier doesn't want everybody racing on hard-ass, long living tires. They want everybody on fast, gum-ball tires that are faster than the competition, tires they can sell lots of. It's not until there is a real-threat of competition does Hoosier come up with an alternative tire everybody can live with. .

For the record, this is not correct. I was the one who pushed for the spec tire and organized the campaign. There was no competition for Hoosier under the open tire rule. 90% were on Hoosiers to begin with. The choice was Hoosier or Toyo and the group did not want the Toyo for the spec tire in SCCA. Hoosier was asked by FRP to develop a longer life tire compared to the R45 bias ply. That tire was based off the SRF tire and Hoosier did so at the request of their customer. This was done for the customer's benefit (FRP and later SCCA racers), not because they had some threat to fend off.

[Daryl DeArman]

I think you're really reaching, Daryl.

As I understand it (after doing a little googling), yes: you'll bump the CR a little bit, but it's going to indeed be a tiny bump. I did find a calculator online that suggests that a change of CR from 10.4 to 10.462351781858523 (a figure from another online calculator) would result in 0.07 more horsepower for a 120hp engine. That's 0.05% (yes: 5/10000 more horsepower).

This is a production Honda replacement piston, so I don't think you're getting anything but a piston that's a tiny bit bigger (and thus heavier). I can't imagine they completely re-engineered the piston for a 0.25mm diameter change.

Yes, reaching to just show that it's not an absolute "no more than proportional to the increase in displacement". As to the weight of the +.25mm piston I would imagine that if a heavier weight isn't spec'd in the rules that the larger piston will be lightened during blueprinting to the same spec as the standard bore piston.

[Daryl DeArman]

My argument is why would you even wish to create a 1% difference when there isn’t one now? Only so a few can save the cost of a new block (I say only a few because many to most will go straight to .010). The cost of changing blocks is already less than what we have to do with Kents. As it is now, this is already another example where the Honda is a savings.

I don't buy the impetus is a cost-savings one. I believe it is a revenue generating one. I don't believe it will make a measurable performance difference that would make it a prudent upgrade. I do believe plenty will go straight to the .010", and I believe that same money/effort would be better spent elsewhere.

[Daryl DeArman]

For the record, this is not correct. I was the one who pushed for the spec tire and organized the campaign. There was no competition for Hoosier under the open tire rule. 90% were on Hoosiers to begin with. The choice was Hoosier or Toyo and the group did not want the Toyo for the spec tire in SCCA. Hoosier was asked by FRP to develop a longer life tire compared to the R45 bias ply. That tire was based off the SRF tire and Hoosier did so at the request of their customer. This was done for the customer's benefit (FRP and later SCCA racers), not because they had some threat to fend off.

You're a smart guy Reid. Do you think Hoosier wanted to risk losing the 90% market share they enjoyed? They had a customer base come to them asking for something different than they were currently offering that base. The threat was that if they said no, that customer base would go elsewhere to fill that need.

Hoosier had tire wars with Goodyear in NASCAR for years. At many dirt tracks across the county there were tire wars between Hoosier and McCreary. Hoosier has now chosen to enter the Supercross/Motocross world to battle with Dunlop and Pirelli. They've been sued over the spec tire bidding process in certain series but bitched and moaned when Goodyear got the nod from NASCAR.

[reidhazelton]

You're a smart guy Reid.

You don't know me very well I see.

Your claim was Hoosier responded to a threat. There was no threat. They were already the spec tire, and would have very likely kept being the spec tire as no one can match their track support, quality, and price. Others might be able to get 2 of the 3.

Back in bias ply days, the R35 was the fast tire. Yet, I was part of a tire test where they were competing with themselves in developing a new construction for the 7" R35. If having market competition qualifies as threatening them, then yeah I guess, but there was no ultimatum for them to do it. I took "threat" as a demand with implied consequence - if you meant something else I misunderstood. See...not so smart.

[billtebbutt]

To be clear, I am not made of money. Nor do I make light of suggesting that others spend their hard earned $s when there may be better ways around a problem.

However, the issue here is that after only a few years with the FIT, we are indeed seeing rules creep where it need not. A replacement block is readily available, right? And that block is reasonably priced at US$800, correct? (or in Cdn$, about $3,000 !)

Generally, engine rule changes make most sense (to me, anyhow) when parts availability is poor, or when parts cost is ridiculous. Respectfully, that is not the case here. $800 for a new block? Sign me up!!!!

BTW, I have zero issues with the Honda. I am generally in favour of anything that increases participation in our sport. The absence of a 10 thou over rule probably won't park a Honda......

best,
BT

[Daryl DeArman]

If having market competition qualifies as threatening them, then yeah I guess, but there was no ultimatum for them to do it. I took "threat" as a demand with implied consequence - if you meant something else I misunderstood. See...not so smart.

Yeah, you don't have to give an ultimatum for it to be a threat. All the market has to do is have a demand or desire something you don't currently offer.

Which brings me back to the Honda Fit vs. Kent situation. At the time the Fit was introduced the market was wanting a lower-maintenance, longer-lasting, more plentiful engine with much more parity. Ford didn't recognize/care about the threat until the Honda was pretty much a done deal. They weren't proactive, they were reactive. I just said I didn't blame Jay for being reactive. Why would you choose to sell a product less often for less money if you didn't perceive the market wanted something different?

[reidhazelton]

Ford didn't recognize/care about the threat until the Honda was pretty much a done deal. They weren't proactive, they were reactive. I just said I didn't blame Jay for being reactive. Why would you choose to sell a product less often for less money if you didn't perceive the market wanted something different?

Ford wanted SCCA to accept the Duratec when the rest of the FF world switched over. SCCA said no. Ford was planning and starting to cast Kent blocks before the Honda was in play.

One thing Honda did that Ford also did to 'compete' is in Runoff's contingency. Honda put up something like $3500 for the first Formula F Runoffs and Ford followed suit. That's pretty cool.

[reidhazelton]

For funsies, I called a few local junkyards about Fit engines. They can get one in a week, under 30k miles, for about $1,000 shipped or less. Several over 50k miles for under $700. To my knowledge, based on conversations with 2 builders all they really do to the blocks are a light hone and 50k on a street block doesn't matter.

We don't seem to have a supply issue.

For those claiming they have to spend $5k, I'll do you a solid and sell you a block for half that - as many as you want.

[reidhazelton]

I also called HPD for a price on the pistons and rings. What's most interesting is the .010" piston is a stock, Honda service part, not an HPD part. What dealer is overhauling and boring out a Honda Fit and not just R&R the engine? Strange.

That said, the person I called at HPD couldn't find a price and was unaware of the piston being legal. I take nothing from that other than they just didn't know - no biggie. They suggested I call a local dealer as the part number is a stock Honda part.

A local dealer tells me a piston is $67 and a ring pack is $52, for a grand total of $476. The first thing he said when he pulled up the part number was "Honda makes an oversized service piston for a Honda fit?!" For argument sake, let's say HPD gives you a deal and the price is $350 shipped. How much is it to bore a block? $200? Total; around $550 for the new pistons, a bore and a hone.

How much is being saved here? We are allowing creep to save at best $450 to $250 on a rebuild on an engine that lasts several SCCA seasons?

If sleeveing a Kent is $600 then it's a no brainer to allow Kents .010's, and since it's been argued .010 doesn't matter, .025s should be just fine too.

[stonebridge20]

Ford wanted SCCA to accept the Duratec when the rest of the FF world switched over. SCCA said no. Ford was planning and starting to cast Kent blocks before the Honda was in play.

Correct. Thanks to Jay Ivey and his boys who looked past their bank account balance and did a solid for the class.

[DanW]

How much is being saved here? We are allowing creep to save at best $450 to $250 on a rebuild on an engine that lasts several SCCA seasons?

If sleeveing a Kent is $1200 then it's a no brainer to allow Kents .010's, and since it's been argued .010 doesn't matter, .025s should be just fine too.

Sleeving a Kent is about $600 with the good flanged sleeves. A prepped new block is $1500 and uses the better thrust washers.

[reidhazelton]

Sleeving a Kent is about $600 with the good flanged sleeves. A prepped new block is $1500 and uses the better thrust washers.

Thanks Dan, I'll correct my post.

[Roland V. Johnson]

All this mathematical certainty about how little extra power the larger Fit pistons will give should be backed up with facts. Just publish the back to back dyno results. When the forged pistons, the alloy head, the new crank shaft, etc were introduced for the Kent engine rigorous dyno testing was required to prove these parts did not give a competitive advantage (other than less fragile). Ivey actually dynoed an engine with the cast pistons, pulled it off the dyno, installed the new pistons with the same rings and dynoed it again to prove the pistons were not a competitive advantage. The engine never really got cold between runs. Yes his dyno, with the correction factors, is repeatable. In addition that information was shared with all the major Ford engine builders, who were also supplied with one of the parts for their inspection. Is Honda now allowed to just say the piston is OK and away we go?

alangabaker I really did not check your math, but did you remember to multiply by 4?

[Daryl DeArman]

Yes his dyno, with the correction factors, is repeatable.

It's all a matter of degree. The best of the best dyno's, with the latest software, "constantly" adjusting for the correction factors are in the .2% range, that's assuming no changes in engine oil temp, engine coolant temp or fuel temp (those variables aren't inputs in the correction factors, but your motor knows the difference). You aren't tuning 120HP motors on a dyno looking for 1/4 HP differences, so that is more repeatability/accuracy than anybody needs. However, that also means you can not objectively determine whether a change that showed a very small power increase was due to the change made or the variance in pull conditions and dyno itself.

[alangbaker]

alangbaker I really did not check your math, but did you remember to multiply by 4?

There's no need, Roland. I was making proportional comparisons.

Total HP increase is proportional (roughly) to total displacement increase.

Total displacement is proportional to single cylinder displacement.

Single cylinder displacement is proportional to the square of the bore.

Ergo, total HP increase is proportional (roughly) to the square of the increase in the bore, or:

(73.315/73.065)^2 * 100, or roughly 100.685% of original HP

If a Honda makes 120hp (roughly) before you overbore it, it will make 120.822hp afterwards.

But a tiny bump in compression ratio will increase that figure by a few thousands of an HP...

...and slightly worse breathing will decrease it by probably more than that increase.

[alangbaker]

Ford wanted SCCA to accept the Duratec when the rest of the FF world switched over. SCCA said no. Ford was planning and starting to cast Kent blocks before the Honda was in play.

Was Ford actually planning it...

...or was Ivey pressing for it, but what got it done was actually having the Honda proposal out there?

I honestly don't know.

One thing Honda did that Ford also did to 'compete' is in Runoff's contingency. Honda put up something like $3500 for the first Formula F Runoffs and Ford followed suit. That's pretty cool.

It is. But again: would Ford have done it if Honda hadn't come along?

[DanW]

Was Ford actually planning it...

...or was Ivey pressing for it, but what got it done was actually having the Honda proposal out there?

I honestly don't know.

Jay had been working with Ford for more than a year to cast new Kent blocks. Jay contributed much of what he learned to improve Kent longevity. The project made a business case to Ford because of the hundreds of thousands of Bobcat Skid Steers, Clark forklifts, Zamboni ice machines and other equipment that needed a supply of fresh replacement Kent blocks. FF is probably less than 1% of the total casting production.

I'm grateful he stepped up and advocated the design changes and production.

[Roland V. Johnson]

Has there been dyno testing to show the changes the oversize piston makes?