Rev Limiting Problem On Fe3 !!!!!!! Helppppppppp

**ausfe3tx5** · 7-4-02, 8:06

I have a problem! im running the fe3 engine with aftermareket ecu for some unknown reason the engine cuts out at 7000rpm on the dot everytime, i know this because i used a data logger to check all parameters.

ive tried everything, some ppl said its the camshafts others say valve springs but how could this be, if it was any of the above why is the cutout sudden and allways spot on 7000rpm surely something like the dizzy is responsible for this has anyone rev there engine past 7000rpm here ?

the fe3 has double balve springs so im thinking it cant be the problem

come on ppl lets get the thinking caps on..........................

**boostedFE3** · 7-4-02, 9:22

Quote:

Originally posted by ausfe3tx5
I have a problem! im running the fe3 engine with aftermareket ecu for some unknown reason the engine cuts out at 7000rpm on the dot everytime, i know this because i used a data logger to check all parameters.

ive tried everything, some ppl said its the camshafts others say valve springs but how could this be, if it was any of the above why is the cutout sudden and allways spot on 7000rpm surely something like the dizzy is responsible for this has anyone rev there engine past 7000rpm here ?

the fe3 has double balve springs so im thinking it cant be the problem

come on ppl lets get the thinking caps on..........................

Trust me... It's the valve springs. I have DIS on mine and it does it at 7500 RPM. Those double valve springs are a good idea, but Mazda used two soft springs. But I had a company to make tougher valve springs, but I haven't had time to try them out on my car yet??? Or a customer's car either....

**ausfe3tx5** · 7-4-02, 9:49

there is a bloke here in aus same engine and has same rev cut exactly at 7000rpm.

how does your rev to 7500rpm?

what type of distrubutor do u have ,we are running the original optical ignition. the ecu we got supplies 8volts to dizzy.,
but mazda workshop manual states 12volts could this be a limiting factor?.

although after all this crap ive been through it does sound mechanical as youy say, i cant see any other fault.

thanks jay b

**boostedFE3** · 7-4-02, 15:01

Quote:

Originally posted by ausfe3tx5
there is a bloke here in aus same engine and has same rev cut exactly at 7000rpm.

how does your rev to 7500rpm?

what type of distrubutor do u have ,we are running the original optical ignition. the ecu we got supplies 8volts to dizzy.,
but mazda workshop manual states 12volts could this be a limiting factor?.

although after all this crap ive been through it does sound mechanical as youy say, i cant see any other fault.

thanks jay b

My revs to 7500rpm sometimes.... but the fuel curve at that rpm has to be very lean. It's valve float!!!

**a763811** · 7-4-02, 19:13

i thought the fe3's didnt redline untel 7800 rpm's and could always rev this high with out any problems.... am i wrong? can they not rev that high? or do they rev that high at first, and then as the springs wear, or if you get an aftermarket ECU can they not rev that high?

**ausfe3tx5** · 7-5-02, 10:29

Quote:

boostedFE3 My revs to 7500rpm sometimes.... but the fuel curve at that rpm has to be very lean. It's valve float!!!

isnt there a valve spring that can be adopted from another engine? are u changing both springs or one of them?

and your rite about the fuel mixtures ive tried enriching it witch caused the rev limit to drop to around 6600 rpm so once i leaned it out again it went back up to 7000 rpm

if u can jay can u keep us updated on the springs !!!!!

**ausfe3tx5** · 7-5-02, 14:33

jay b , i found this site talking about rev problems do u think this relates to our problem?? see below for a copy of the article.

Quote:

Cosworth engines use service-free hydraulic cam followers, and as the cam profiles are not very radical, and the standard engine is designed to rev to 6500 or thereabouts these are satisfactory. However when more extreme cam profiles and higher RPM bands are used, these tend to pump-up resulting in valve/piston contact. Every Cosworth engine I have seen has had 'kiss-marks' on the pistons due to over-revving. Valve piston contact is a definite no-no especially at the sort of RPM (8500+)

ALSO BELOW:

Quote:

On the inlet however I used proper light steel followers to avoid valve float. I have since discovered that Fiesta Diesel cam followers fit and these are of the solid shimmable type.

**veltpak6** · 7-7-02, 22:25

BUMP ^^

btw - what about all those guys revving their FE DOHC's to 8800rpms etc? How can a dual valve spring engine have more valve float than the freaking F2 (I mean even *it* can rev a bit past its redline)

hmmmmmmm

I'm hearing too many conflicting things ... hmmm ... !?

**ausfe3tx5** · 7-8-02, 5:38

Quote:

btw - what about all those guys revving their FE DOHC's to 8800rpms etc? How can a dual valve spring engine have more valve float than the freaking F2 (I mean even *it* can rev a bit past its redline)

well if u see the qoutes i poisted on my last reply thats what i think it is, i dont beleive untill i see the results from jay b , that valve float is the problem. it could have something to do with the hla,s which in turn makes the valves float id say..

i dont think mazda would have built an engine so fine only to foget about valves and springs , do u ?????

i will get to the bottom of this and i do take into account all suggestions

thanks for all the help

also if you want to see my fe3 redlining it and hitting the cut out go to my website and download the ausfe3 zip files then i want comments on what it sounds like .....
AUSFE3 HITTING REV LIMIT VIDEO DOWNLOAD NOW

**veltpak6** · 7-8-02, 23:18

hey AUS,

what cams does your FE3 have? If you take off the valve cover, there is a casting on both the intake and exhaust cams.

Mine are:

IN - FEAP
EX- FE3N (I think this one is standard)

lmk! tia.

**veltpak6** · 7-8-02, 23:28

OH HEY, Aus, one more thing, I downloaded your videos and I noticed that even though the RPMs seem dormant at 7200 there is an intermittent rumbling noise that seems like a fuel or ignition failure....(or float!) what is that exactly???? are you sure the computer isnt reporting errors (ignition signal) or any sort of rev-limit?

**cam22t** · 7-9-02, 0:33

On mine its more like valve float , give it revs over 7200 and it sounds like valve train float . The whole top end goes loose .

My cams are the same as yours.

The engine has 69 000 km on it and it is the unleaded model.
quote:
--------------------------------------------------------------------------------
btw - what about all those guys revving their FE DOHC's to 8800rpms etc? How can a dual valve spring engine have more valve float than the freaking F2 (I mean even *it* can rev a bit past its redline)
--------------------------------------------------------------------------------

im wondering if also the hla shim is venting pressure ...

**veltpak6** · 7-9-02, 1:43

gee ripes man,

looks like new valve springs are in order.... either that and/or solid lifters & shims. *shaking head*

thats a real crying shame.

7-9-02, 4:23

teK - you have your FE3 up and running yet? what are your redline set at?

**ausfe3tx5** · 7-9-02, 5:46

Quote:

Cosworth engines use service-free hydraulic cam followers, and as the cam profiles are not very radical, and the standard engine is designed to rev to 6500 or thereabouts these are satisfactory. However when more extreme cam profiles and higher RPM bands are used, these tend to pump-up resulting in valve/piston contact. Every Cosworth engine I have seen has had 'kiss-marks' on the pistons due to over-revving. Valve piston contact is a definite no-no especially at the sort of RPM (8500+)

Quote:

On the inlet however I used proper light steel followers to avoid valve float. I have since discovered that Fiesta Diesel cam followers fit and these are of the solid shimmable type.

somehow i think above remarks mite be close to the point.
more in these soon
im running full aftermarket ecu rev limit set at 8000rpm !i dont think its fuel or ignition as i gave it more fuel and less allways the same prob,same goes wit the timing

7-4-02, 8:06	#1 (permalink)
ausfe3tx5 Join Date: Apr 2002 Location: SYDNEY iTrader: (0)	Rev Limiting Problem On Fe3 !!!!!!! Helppppppppp I have a problem! im running the fe3 engine with aftermareket ecu for some unknown reason the engine cuts out at 7000rpm on the dot everytime, i know this because i used a data logger to check all parameters. ive tried everything, some ppl said its the camshafts others say valve springs but how could this be, if it was any of the above why is the cutout sudden and allways spot on 7000rpm surely something like the dizzy is responsible for this has anyone rev there engine past 7000rpm here ? the fe3 has double balve springs so im thinking it cant be the problem come on ppl lets get the thinking caps on..........................
	sold my mazda so im mazdaless for now, currently got my soarer to keep me going till next time.twin turbo time ........................................................... _-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_- ______________________________ (.)(.)(.)(.)(.)(.)(.)(.)(.)(.)(.)(.)(.)(.)(.)(.)(.)

7-4-02, 9:49	#3 (permalink)
ausfe3tx5 Join Date: Apr 2002 Location: SYDNEY iTrader: (0)	there is a bloke here in aus same engine and has same rev cut exactly at 7000rpm. how does your rev to 7500rpm? what type of distrubutor do u have ,we are running the original optical ignition. the ecu we got supplies 8volts to dizzy., but mazda workshop manual states 12volts could this be a limiting factor?. although after all this crap ive been through it does sound mechanical as youy say, i cant see any other fault. thanks jay b
	sold my mazda so im mazdaless for now, currently got my soarer to keep me going till next time.twin turbo time ........................................................... _-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_- ______________________________ (.)(.)(.)(.)(.)(.)(.)(.)(.)(.)(.)(.)(.)(.)(.)(.)(.)

7-7-02, 22:25	#8 (permalink)
veltpak6 Join Date: Jul 2001 Location: Toronto, Canada? Age: 27 iTrader: (0)	BUMP ^^ btw - what about all those guys revving their FE DOHC's to 8800rpms etc? How can a dual valve spring engine have more valve float than the freaking F2 (I mean even it can rev a bit past its redline) hmmmmmmm I'm hearing too many conflicting things ... hmmm ... !?
	1993 323 ZE

7-8-02, 23:18	#10 (permalink)
veltpak6 Join Date: Jul 2001 Location: Toronto, Canada? Age: 27 iTrader: (0)	hey AUS, what cams does your FE3 have? If you take off the valve cover, there is a casting on both the intake and exhaust cams. Mine are: IN - FEAP EX- FE3N (I think this one is standard) lmk! tia.
	1993 323 ZE

7-8-02, 23:28	#11 (permalink)
veltpak6 Join Date: Jul 2001 Location: Toronto, Canada? Age: 27 iTrader: (0)	OH HEY, Aus, one more thing, I downloaded your videos and I noticed that even though the RPMs seem dormant at 7200 there is an intermittent rumbling noise that seems like a fuel or ignition failure....(or float!) what is that exactly???? are you sure the computer isnt reporting errors (ignition signal) or any sort of rev-limit? Last edited by veltpak6 : 7-8-02 at 23:36.
	1993 323 ZE

7-4-02, 19:13	#5 (permalink)
a763811 Join Date: Feb 2002 Location: denver Age: 24 iTrader: (0)	i thought the fe3's didnt redline untel 7800 rpm's and could always rev this high with out any problems.... am i wrong? can they not rev that high? or do they rev that high at first, and then as the springs wear, or if you get an aftermarket ECU can they not rev that high?

7-9-02, 0:33	#12 (permalink)
cam22t Join Date: Jan 2002 Location: Brisbane, Australia iTrader: (1)	On mine its more like valve float , give it revs over 7200 and it sounds like valve train float . The whole top end goes loose . My cams are the same as yours. The engine has 69 000 km on it and it is the unleaded model. quote: -------------------------------------------------------------------------------- btw - what about all those guys revving their FE DOHC's to 8800rpms etc? How can a dual valve spring engine have more valve float than the freaking F2 (I mean even it can rev a bit past its redline) -------------------------------------------------------------------------------- im wondering if also the hla shim is venting pressure ...
	89 MX6. 4WS. FE DOHC Turbo. Garrett GT2876r Turbo. Wiesco Forgies. EMS 8860 ECU. 3 Inch Exhaust. Torsen Diff. 2500lb RX7 Clutch. 18 inch Rays Sebring ITC-S wheels. Cusco Camber Plates and Coilovers. Bosch 044 Pump. 750cc Injectors. 12.1 @ 116mph. 425hp (317kw) atw's http://au.youtube.com/user/cam22t

7-9-02, 1:43	#13 (permalink)
veltpak6 Join Date: Jul 2001 Location: Toronto, Canada? Age: 27 iTrader: (0)	gee ripes man, looks like new valve springs are in order.... either that and/or solid lifters & shims. shaking head thats a real crying shame.
	1993 323 ZE

7-9-02, 4:23	#14 (permalink)
AusMX6_old Location:	teK - you have your FE3 up and running yet? what are your redline set at?
AusMX6_old Location: