North American Turbocoupe Organization



A brain fart question (Timing)
Dan E Offline
Posting Freak
#1
Sorry for the rambling in advance [Image: rolleyes.gif]

We were discussing the running problems that POWEREDBYPSI (Zach) was having the other day.

The subject of having the engine firing on the Exhaust Stroke rather than the Compression Stroke came up.

I'm having a period of CRS here...

Isn't it correct that the only way for the engine to be firing on the Exhaust Stroke (if the Crank is at TDC and them Cam is on its mark) would be for the rotor to be pointing to the #4 post ?

Put a different way... The Crank rotates twice for each rotation of both the Cam and the Aux shaft, correct ? If the Crank is lined up to TDC and the Cam is on its mark and the Dist rotor is pointing to #1 post, then there is no way it is off 360 degrees, correct ?

Then if you rotated the crank (once) 360 degrees and put it back at the TDC mark, the Cam would be pointing 180* off its mark and the rotor would point to #4 post. Right ?

So, anytime the crank is aligned to the TDC mark on the timing marker (or if it is aligned using the timing belt shield [that is over the crank sprocket] notch with the notch on the crank oil seal housing) the #1 piston is going to be at TDC, right ? For that matter, the #4 piston will also be at TDC, right ?

So back to my original question...the only way to have it fire on the Exhaust Stroke is to have the Aux. Shaft / rotor 180* off (assuming the cam is correct)....right ??????

------------------
Dan Eaves
88TC 5spd, Crower 5.5" Sportsman Rods, Short Wiseco Pistons bored .030" Over, Ported Head with Polished Combustion Chambers, Gutted & Polished Upper, Ported & Polished Lower, Polished T/B, Ported E6, SVO T3 .63AR Turbo, Bosch Bypass Valve, 3" DP w/No Cat, 2 1/2" DynoMax single cat back w/DynoMax Super Turbo Muffler, RR Cam, K&N in Fenderwell, Gillis Boost Valve, Centerforce I Clutch, Removed A/C, Polished Wheels, Polished Valve Cover, Polished Crank and W/P Pulleys, Walbro 255LPH HP Pump, Kirban Adj FPR, and the DAMN Heater Core is new too !

http://www.geocities.com/wot_turbo/WOT.html

NATO MEMBER (Vice Chairman...if it's a vice...I deal with it)
Dan Eaves
88TC 5spd Vermillion Red, Polished...everything...
Reply

Dick Murphy Offline
Member
#2
Anyone besides you and me reading this. I'm going to the garage and move the cam belt one cog. I have a large investment contract to bid tomorrow. Talk to you later.

Dick
88 TC
91 Mustang LX with 85 XR7 motor
77 Lotus Esprit
87 Mercedes 190
91 Mercedes SL 300
66 Mustang
Reply

Dick Murphy Offline
Member
#3
By the way, I assume Can't Remember S*** is a technical auto term.
88 TC
91 Mustang LX with 85 XR7 motor
77 Lotus Esprit
87 Mercedes 190
91 Mercedes SL 300
66 Mustang
Reply

Dan E Offline
Posting Freak
#4
What ? Nobody wants to let me know if I'm right or wrong ????
Dan Eaves
88TC 5spd Vermillion Red, Polished...everything...
Reply

turboken Offline
Member
#5
Well, Dan, technically you should be right, I mean that is what I always thought, but I had a prob with timing once, and i loosened everything, and rotated the crack 360 degrees (leaving the cam and jack shaft alone), and then it ran fine??? These engines sometimes have a mind of their own and defy laws of physics (except Murphy's law). But as my ex-girlfriend summed up my attitude perfectly, " Id be in trouble if your loved me as much at you love that car."

------------------
88TC- all options minus leather: 129K miles, new motor, bored and balanced block, roller cam(FordMotorSports), Crane ignition and coil. Powerhead with big valves, ported intakes and exhaust, 5 spd with FMS rebuild kit, B&N ripper shifter, K&N cone,
9.564 in the 1/8 mile

93 SC with all options minus the JBL system. Stock (pully??12PSI??) with drop in K&N filter.
9.886 1/8 mile
88TC-Black/Raven,A237 cam,ported and polished intakes/exhaust, gillis valve, o-ringed deck, head studs
85 Xr7 rough survivor 82k miles
2008 Subaru Impreza non turbo :-(
73 Honda CB750 (running parts bike for dads '69)
04 Honda 1000rr
Reply

turboken Offline
Member
#6
P.S.

I told her not to worry about that ever happening. Ain't I a stinker....

KEN ;-)
88TC-Black/Raven,A237 cam,ported and polished intakes/exhaust, gillis valve, o-ringed deck, head studs
85 Xr7 rough survivor 82k miles
2008 Subaru Impreza non turbo :-(
73 Honda CB750 (running parts bike for dads '69)
04 Honda 1000rr
Reply

BJL Offline
Moderator
#7
My girlfriend said i love my car more then her. My reply, my car gives it to me when i want! and all i ahve to wait for is a lil bit of turbo lag, not soem lame excuse, and the car is never tired.
Im glad she dotn read this she'll kill me, ha ha

------------------
Brian J Larkin
1988 Turbo Coupe 5spd, dark blue , bought form junkyard with blown motor, dropped used motor in drove it for a year, repaint and body work by me, since owned done three head gaskets, 4 clutches, 2 motors and two turbos, one thing about this car, i keep fixing it , it must be the members of this board, always there to help! Thanks guys!

I got tons of spares parts I’m trying to get rid of email me with needs , I sell cheap I wanna get rid of it now

http://crazydriver358.5u.com
Brian Larkin
88TC 330,000 miles
Slightly Modified
Reply

Pete D Offline
Administrator
#8
1. Dan, you are right. Feel better now [Image: biggrin.gif]
2. CRS, uyes it's a very technical automotive term [Image: biggrin.gif]
3. If it's got t..s or tires, your going to have problems with it. But this works both ways!!!!

------------------
NATO Member. it's not a vice, it's an obsession
"The nice thing about each new day is nobody ever used it before" Barnaby Jones
88 TC X 2, 86 SVO, mods list at
http://www.turbotbird.com/showroom/pd_88tc.htm
Pete Dunham


Reply





Users browsing this thread:
1 Guest(s)



Theme © iAndrew 2018 - Software MyBB