carifresco
Member
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- Mazda Protege ES 1999
In PR they rev KL to 10K+ no problem with trans
NA Tech Race to 100whp per 1000cc's
- Thread starter LordWorm
- Start date
with a dog box
anyway, this appears to be an argument neither of us will back down on.
I look forward to the video's of 10k+ rpm shifts on the stock box.
I equally look forward to seeing how nice the idle is on a MS2/MS3 on a build that wild.
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carifresco
Member
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- Mazda Protege ES 1999
Has someone try to fit FS rods on a FP crank??
justanothermp5
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- Rust Bucket
why would you want that? FS rods are terrible, unless your trying to get aftermarket forged rods to fit, then thats a good idea
carifresco
Member
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- Mazda Protege ES 1999
FS rods are longer than FP ones but stiil FP have a better rod ratio but with the FS ones , better rod ratio 8k + rpm
And the award for gross over simplification goes to.....
for starters, i dont think the FP rod ratio is quite as good as you think it is....i dont actually have numbers at hand, but if you measure the big end center to small end center of the rod, you might get a surprise.
secondly, the FS rods on the FP rotating assembly will cause the pistons to clear the deck by something in the order of 3mm.... you need to move the wrist pin up which means custom pistons. The deck on the FP is shorter I believe (again don't have the numbers with me but i believe this is what i was told by a builder about 5yrs ago when i was looking into it)..
thirdly, there is no way in hell i'd ever trust the stock rods at 8k rpm for any prolonged period of time. Hell i wouldn't trust most after market cheap forged rods at that kind of speed without a rod ratio exceeding 1.6:1. Go waaaaay back in this thread, get the spreadsheet i created, and punch in the numbers - the piston acceleration is going to be out of control.
If you want a high RPM FP/FS motor, i suggest sourcing rods from another motor with a bigger wrist pin (SR20 conrods can be machined to fit..), and custom pistons with the wrist pin raised accordingly. Note i've never actually done or even seen this done on an FP, so i dont know if there is quite enough room to move the wrist pin up to get the SR20 rods to work....you'll need to do some math yourself. Also with a bit more work 3SGTE rods may be made to fit the FS...again, you'll need to measure and calculate to get this right.
The FP rod ratio is better than the FS rod ratio because the FP has shorter stroke, not because of the rod length. I'll bet dollars to doughnuts that both engines have the same rod. That being said, the FS Rod ratio is absolutely terrible for high RPM power, so it's not hard to improve it on the FP. Personally, I'd love to see a serious FP build...
never done it myself, but information i've got (which may not be entirely accurate) is that the rods are different and that the deck height on the FP is shorter.
I seem to recall someone suggesting to me that FS rods and FS pistons on FP crank and block and *nothing* else done lead to the pistons clearing the deck by 3mm.
The FP rod ratio is "better", but its not as good as you'd think (its not a case of taking FS rod length and FP stroke - if the information i've got is right the FP rods are shorter again).
Stock F motor rods (except the FE3N, which has more in common with a B series motor) are all pretty pathetic though... one thing is certain without pulling a motor appart to measure things, neither motors con rods are going to put up with serious high RPM abuse.
The shorter crank is certainly the way to go though. Custom long rod kit on a FP crank, overbore the engine out to get 1.9ish litres, and you could have a winner.
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any option for a conversion to solid lifters?
mind you, high RPM is capability is only half the battle won... you then need some pretty extreme bits of gear in the manifold and header department, with nice big cams etc to extract power out of a motor spinning quickly...and you can kiss drivability goodbye when you start going north of 10k....
I kinda think this thread has become a "race to astronomical rpm" thread, not real power
Yeah, you can get solid lifters. I think an 8000 RPM build would be fine for a small 4 cylinder engine. You could get some decent power without any massive sacrifices. But then again, a Formula 1 engine has 10,000 RPM of usable powerband (i.e., from 8000 to 18000 RPM)...go figure
Every think for a moment that I wasn't refering to you?
The general theme of questions I'm answering lately (from most people) is "how do i get more RPM"... without understanding that in a lot of cases you dont NEED the RPM for a particular goal.
Has anyone milled the head to get more compression ratio? The spec number of the stock motor at 9.1:1 is very low. By my calculations milling 0.025" from a stock head would get me 9.88:1.
Still pretty feeble for a CR, but its better than stock. A junkyard rebuild head with a valve job and some dremel tool seat blending is the choice here.
Has anyone tried this?
Still pretty feeble for a CR, but its better than stock. A junkyard rebuild head with a valve job and some dremel tool seat blending is the choice here.
Has anyone tried this?
Just get higher compression pistons.. Milling the head is only going to get you the most trivial of increases in compression.
JDM pistons are a high compression, direct stock replacement option.
JDM pistons are a high compression, direct stock replacement option.
The JDM pistons are nice, but I was trying to do something without having to rebuild the bottom end. Junkyard heads are easy to find, and a little work on one of those keeps me in the range of a driveway swap. If I go for the JDM pistons, I would have to do it along with a rebore & new bottom end bearings and all the fun that goes along with that. Not a bad option, but more than I wanted to spend right now. The 9.9:1 is still pretty feeble though, and that would be at the limit of the milling allowance. If I wanted more in the short term, I'd have to go for a thinner head gasket.
On the bike in my profile pic, I re-used stock pistons but milled the head 0.025" and ran an 0.020" head gasket (stock is 0.040"); got that a bit over 11:1. I did some handheld grinder bowl blending (I know better than to hog out ports without a bench) along with the CR change and made a HUGE difference (77 to 95 hp). Of course, the carbs are easier to reprogram. I was looking for a way to duplicate that process on the Protege: cheap increase.
I was looking for more specific info, in that: will the head-to-valve clearance be okay with 0.025" off the head.
Now that I'm blabbing about it, I just might look into a thinner head gasket at the same time.
On the bike in my profile pic, I re-used stock pistons but milled the head 0.025" and ran an 0.020" head gasket (stock is 0.040"); got that a bit over 11:1. I did some handheld grinder bowl blending (I know better than to hog out ports without a bench) along with the CR change and made a HUGE difference (77 to 95 hp). Of course, the carbs are easier to reprogram. I was looking for a way to duplicate that process on the Protege: cheap increase.
I was looking for more specific info, in that: will the head-to-valve clearance be okay with 0.025" off the head.
Now that I'm blabbing about it, I just might look into a thinner head gasket at the same time.
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- 02' Protege ES (Gone)
16' Mazda 6 sport manual
N/A wise....nothing is cheap forthe pro
