jgrewe

iTrader: (1)

Last part of the first quote, "unless you lower the tranny"

So with all the nice diagrams, you still prove my point. The crank is at the bottom of the engine and most of the weight is above it. I know the oil pan weighs as much as the heads but still You're splitting hairs on the placement in the car. The eshaft is in the middle. The center of gravity is probably pretty close to the stock engine. I think the V8 with aluminum heads is the perfect transplant. I'd probably do a twin/ or single turbo V6 myself to keep thing even further back.

Rotary_Powerd

VQ35? :P 307 hp N/A

jimlab

So? You also said "The eshaft and crankshaft are at the same height in the two engines." Until you provide measurements proving your statement, i.e. that lowering the V8 and transmission is the only difference in centerline location, it's still just a guess.

Wrong. Center of gravity means that half of the weight is above and half of the weight is below.

Formula One regulations state that the center of gravity of their engines must be at least 160mm above the reference plane (bottom of the oil pan). 160mm is only about 6.3". Furthermore, it follows that because there's a rule specifically stating center of gravity must be that high, it is possible for the center of gravity to be BELOW that point.

Do you know what's 6.3" above the bottom of my oil pan? The block... about 1/4" above the crankshaft bearing surface. Hmmm...

Do you know what a strawman argument is?

Wrong. Center of gravity has EVERYTHING to do with the final placement of the engine (and transmission) in the car, especially when the subject of debate is that a V8 negatively affects the center of gravity.

Key word: probably. In other words, you don't know, and you're just guessing...

And then we change the subject...

Boys and girls, that concludes our lesson on Identifying Fallacious Arguments. See you tomorrow, same time.

aussiesmg

iTrader: (1)

Also not true, the reason the T5 and T56 fit so well is the RX trans tunnel is large due to the height of the trans due to it being located behind the eccentric shaft midway down the engine height.

Think about it for a second; the rotors revolve around, (including below) the eccentric shaft, logic tells you this makes the shaft higher.

The Ford 5.0 with aluminum heads, light starter, light flywheel, and accessories removed is just 20lb more than a stock 12a, in exchange you gain around 3 X the torque and 2 X the HP in a stock engine.....whereas a 13T would weight considerably more.

jgrewe

iTrader: (1)

Whatever, I not going to take my time cutting up quotes and wasting peoples time. The original quote I took was a wrong statement, I was just pointing out that the crank or eshaft is going to line up with the input shaft no matter what. To lower either one would require lowering the tranny, so if you didn't do that the V8 would have its weight higher in the chassis. Also, that the weight of a V8 isn't centered around the crank, as even you have pointed out. Its above the crank, which will PROBABLY put it about where the rotary COG is. If it does or not, or if its off an 1" I don't care. I've never gotten that far into putting a "V" anything into an RX.

And the F1 rule, are you running a dry sump? Last F1 engine I saw didn't have a big oil tank sitting below it. So where does that 160mm put the mark on your engine if you start from a point just below the point you crank swings down to at its lowest point. Thats the real place to measure from if you want to compare apples to apples.

jimlab

LS7. Any more stupid questions, or are you done here?

jgrewe

iTrader: (1)

Damn, I had to do a search for "LS7" never looked at them. Hmmm,"Dry Sump Oil System" in big letters... OK, OK but I bet you have a longer stroke to clear than an F1 engine... quietly erasing the mark on the calender 'Got Jimlab'


You engine swap guys get really defensive. I'm not trying to poopoo V8's here, just the statement that was wrong.

Xeros

Jimlab eats noobs for all meals of the day.

jgrewe

iTrader: (1)

Hardly a noob here, just don't care about V8's right now and really don't care about what it does to an RX7 and how it might effect the vehicle dynamics. When I get ready to do a swap like this, if ever, I'll dig for his posts.

Xeros

Its kool, I'm sure your not, I just wanted to say that. Plu sJimlab knows his stuff, his write up bushing replacements is amazing.

Rotary_Powerd

I'm impressed at the wealth of information being presented, I'm learning a lot more than I thought I would.

jgrewe

iTrader: (1)

I know jimlab knows his stuff, I've learned a lot going back and forth with him in the past. I just think he's a little sensitive about the V8 stuff because people get religious about the rotary. He can slice up my posts all he wants, the facts are still the same.

The eshaft is in the middle of the engine, probably the center of gravity with out all the outside extras.

A crank shaft is at the bottom of the engine, below the center of gravity.* my original point from the quote I chopped that started all this crap. The weight is not concentrated at the crank, there is just a lot of it there. The center of gravity is what counts and its above the crank.

These shafts line up with an input shaft of a tranny.

If you install a V8 with it lined up with a stock height input shaft the center of gravity of the V8 will end up higher than the rotary.

You can lower a V8 in the chassis only by lowering the tranny.

You can probably get the center of gravity of the V8 close to the rotary center of gravity.

I have used the word PROBABLY a few times that it because I have better things to do with my time than go out with my scales, weigh these parts, jack up one end on the scales and weigh them again, do the math to figure out the COG and report back for jimlabs approval and spelling check. Go back and read the posts, my points are the same, jimlab has taken parts of statements and felt he needed to say I'm wrong about something then prove me wrong with a correct statement that doesn't prove me wrong.

sub9lulu

iTrader: (7)

jimlab takes every ******* thing people say about the (his) ls7 / fd personally
doesnt matter if other people is right or wrong jim STILL wants to prove other people wrong wtf lol
i dont know how many people left this forum just because of getting of arguing with him

this thread has been great i hope that it doenst turn into another flame war lol

btw john i m with u, i know that u know your ****

KaoticFdR1

good luck finding his Epic thread as it was deleted IIRC how many pages was it up to like 300?

Also its just the internet and we have the freedom of choice you can choose to believe the facts he's presented to you or not....no need to close your account to an Internet Forum because someone argues with you....the fact is the majority of the members on here don't know eachother or aren't in constant personal contact with eachother for a person to have to defend themselves to one another. Basically don't take it personally.

Directfreak

iTrader: (2)

I think it's pretty good.

jgrewe

iTrader: (1)

I wouldn't come here if I didn't think I might learn something. Yes, I've learned stuff dealing with jimlab, and, no I don't take anything here personally.

And only sub9lulu has been to my game room, uh, I mean shop.

wardaj

Im going to put a power stroke in mine.

wptrx7

I don't understand how you entered this thread if you don't care?

jgrewe

iTrader: (1)

Just bored I guess, and I know the subject brings out zealots on both sides. I just don't have a dog in the fight. 25 years building cars and swapping engines gives me some insight, beyond that an RX7 is just another engine donor or recipient to me.
I've done; 12a in an MGB, Buick V6/T-5 in an Opel Manta, VW water cooled sandrail, 13B in a Miata,454 in '57 Chevy, and laying around waiting for the right chassis is an engine mount, header and oil pan I made to put a 12a in a MG Midget. So I've seen the problems and lived with some evil handling cars that went fast in a straight line. And from the numbers I've seen an LS7 looks like the perfect engine to stuff into an RX.

sub9lulu

iTrader: (7)

yea thats why i m putting one in mine, ls1, not as powerful, but it'll do the job

jkstill

iTrader: (11)

As much I like the FD, if I want V8 power I'll just find a 2000 Corvetter FRC. Not quite as precise handling, but pretty good, and much less work.

Not that I'm trying to put anyone else off doing V8 swaps, I just don't think it worth the trouble myself.

The Driver

iTrader: (4)

Carbon UIM an Carbon LIM's FTW!!!! No piston engine has **** like that!

They are produced by feed you can find them in the CC craftcompany blogs somewhere among the other millions of carbon parts for the sevens.

RX7SIGN

For autocross, time attack, etc all the famous records in RX7s have been set wit rotaries.. im not taking anyside just stating facts.. 1

Rotary_Powerd

back to physics please

themaverick

http://www.motorsportsne.com/2007/re...2007ax_fin.htm this link shows an rx7/ls1 competing in the "U" class (unlimited street car) that set fast time of the day. im sure there are many of these for the rotary powered 7's as well. its proven that both cars handle very well. so lets get back to the topic of what physics build a better sports car.