Crankshaft Pulley size - LotusTalk

cpeteod · 02-15-2009, 07:45 PM

Everyone, to save me time from trying to measure in the dam tight engine compartment, what is the size of the stock Crankshaft pulley on our engines. Also I did a search and only noticed one option for a smaller crankshaft pulley option. Anyone have a constructive opinion on a pulley set. I saw a 4.25 inch aluminum one on ebay.

Ok i just noticed someone mentioned that our pulley is 5 inches. I found this on the forum after a hour of searching. Is this correct?

dustylax · 02-15-2009, 08:44 PM

you are not aloud to do this.

cpeteod · 02-15-2009, 08:49 PM

lol Call me tomorrow :P I will tell you why. I did some math and i need to know exactly how big the dam pulley is down to the mm.

Quote:

Originally Posted by dustylax

you are not aloud to do this.

elise/europa · 02-15-2009, 09:31 PM

The measure I have on my notes is 5.2, measure taken over the belt. I was looking to have the pitch diameter when I took te measurement, and the pitch diameter is around at the outside face of the belt. The flange of teh pulley was something like 5.3.

Reducing the diamater of this pulley can be not welcome for the cooling, the boost if you have a blower etc

Dragon · 02-15-2009, 11:50 PM

If you look around the inter web and search the forum you'll find that these pulleys are bad juju on the 2zz and can cause bearing damage due to the lack of a harmonic dampener. Your better off keeping the stock crank pulley and under driving the accessory pulleys.

dstevens · 02-16-2009, 06:34 AM

Bad idea. The replacement pulley is machined out of a single piece of metal and will not have the rubber damped inertia ring. #5 crank bearing gets worn on both edges.

cpeteod · 02-16-2009, 07:34 AM

Quote:

Originally Posted by Dragon

If you look around the inter web and search the forum you'll find that these pulleys are bad juju on the 2zz and can cause bearing damage due to the lack of a harmonic dampener. Your better off keeping the stock crank pulley and under driving the accessory pulleys.

Thanks, I did find that late last night. Bad idea on replacement pulleys. Still the 5.2 concerns me because i have seen notes from 4.8 to 5.2 on the pulley. The exact number is needed because i am so close to maxing out the RPM range at 8300rpm. If the pulley is 4.8 inches i can go up to about 8500rpm. If it is 5.2inches i can go to 8100 rpm.

dustylax · 02-16-2009, 01:36 PM

what benefit will you get by going to 8500 ?

Dragon · 02-16-2009, 03:01 PM

Quote:

Originally Posted by cpeteod

Thanks, I did find that late last night. Bad idea on replacement pulleys. Still the 5.2 concerns me because i have seen notes from 4.8 to 5.2 on the pulley. The exact number is needed because i am so close to maxing out the RPM range at 8300rpm. If the pulley is 4.8 inches i can go up to about 8500rpm. If it is 5.2inches i can go to 8100 rpm.

I'm still not clear on what you want to under or over drive. Also with out a built engine (head and block) things will start coming apart if you push the rpms. If you can gives us a few details about what it is that your trying to do maybe we can help you out.

elise/europa · 02-16-2009, 03:49 PM

very strange topic. the size of the pulley don't have any effect on maximum rpm at all. the pulley is not an harmonic pulley like al in-line 4 engine.

it is like talking about a none issue thing...

i drive my car all the time at 8500, if it is ok for 2 seconds, it is ok for 2 hours.

cpeteod · 02-16-2009, 04:42 PM

Ok let me back track. I am not trying to under or over anything. The reason i need to know what size the pully to the mm is that the size of the crankshaft pulley has a direct relationship to a supercharger RPM level. I just wanted to know what i would be pushing the supercharger to. My supercharger has a higher ratio then most supercharger do. I am doing just some simple math but need to know exactly how many mm or inches the stuipd pulley is and it is hard info to find. I thought it was 5inches (127mm). If the pulley is 123mm, that difference would mean i could rev the engine to the current fuel cut off limit. If not i have to lower the limit. Hope that explains why i just need to know what the size of the pulley is to the mm.

Example: A= B * (C/D) * SUPERCHARGER RATIO

(A) Im Peller speed max.
(B) Engine speed max.
(C) Diameter of crank shaft pully
(D) Diameter of supercharger pully

02-15-2009, 07:45 PM	#1 (permalink)
cpeteod 2006 elise, 2007 BMW 335i Join Date: Jun 2007 Location: New York Posts: 116	Crankshaft Pulley size Everyone, to save me time from trying to measure in the dam tight engine compartment, what is the size of the stock Crankshaft pulley on our engines. Also I did a search and only noticed one option for a smaller crankshaft pulley option. Anyone have a constructive opinion on a pulley set. I saw a 4.25 inch aluminum one on ebay. Ok i just noticed someone mentioned that our pulley is 5 inches. I found this on the forum after a hour of searching. Is this correct? Last edited by cpeteod : 02-15-2009 at 08:31 PM.

02-15-2009, 08:44 PM	#2 (permalink)
dustylax 2.0-6262 Join Date: May 2007 Location: NY Posts: 437	you are not aloud to do this. __________________ Please PM if you need anything, i am working from home now.

02-15-2009, 09:31 PM	#4 (permalink)
elise/europa Registered User Join Date: Jan 2007 Location: montreal Posts: 348	The measure I have on my notes is 5.2, measure taken over the belt. I was looking to have the pitch diameter when I took te measurement, and the pitch diameter is around at the outside face of the belt. The flange of teh pulley was something like 5.3. Reducing the diamater of this pulley can be not welcome for the cooling, the boost if you have a blower etc __________________ ____________________________________ Elise 2006, white, Katana Europa 1969, green, H22A, 194 whp, 1550# CONFIGTECH.ca / Solidworks

02-15-2009, 11:50 PM	#5 (permalink)
Dragon Hydrocarbons Rule Join Date: Sep 2007 Location: Okinawa Japan Posts: 1,747 Images: 2	If you look around the inter web and search the forum you'll find that these pulleys are bad juju on the 2zz and can cause bearing damage due to the lack of a harmonic dampener. Your better off keeping the stock crank pulley and under driving the accessory pulleys. __________________ 2006 Exige; BWR Supercharger, Adj Sway Bar, Ohlins Suspension, BSK Oil Catch Can, Moroso Oil Pan, ORC Clutch, Custom Exhaust, Black Volk Racing CE28N's w/ Toyo R1R's, 2 piece rotors, Pagid Blue Pads, BSK Wet Carbon (Side Skirts, Front Lip Spoiler, Gas Cap Cover, Center Console, Door Panels), Dry Carbon rear Diffuser, Harness Bar, BWR Gauge Mount, OMP Superquadro steering wheel, LETSLA Short Shifter, V2arms, Rear Tow Link Brace, RLS Battery Bracket, BOE Tow Bar, Stickers.

02-16-2009, 06:34 AM	#6 (permalink)
dstevens 2zz exorcism complete Join Date: Mar 2007 Location: California Posts: 398 Images: 4	Bad idea. The replacement pulley is machined out of a single piece of metal and will not have the rubber damped inertia ring. #5 crank bearing gets worn on both edges. __________________ -2ZZ +K24 +150hp +118tq +7mpg +LSD -30lbs -CoG +F.bias

02-16-2009, 01:36 PM	#8 (permalink)
dustylax 2.0-6262 Join Date: May 2007 Location: NY Posts: 437	what benefit will you get by going to 8500 ? __________________ Please PM if you need anything, i am working from home now.

02-16-2009, 03:49 PM	#10 (permalink)
elise/europa Registered User Join Date: Jan 2007 Location: montreal Posts: 348	very strange topic. the size of the pulley don't have any effect on maximum rpm at all. the pulley is not an harmonic pulley like al in-line 4 engine. it is like talking about a none issue thing... i drive my car all the time at 8500, if it is ok for 2 seconds, it is ok for 2 hours. __________________ ____________________________________ Elise 2006, white, Katana Europa 1969, green, H22A, 194 whp, 1550# CONFIGTECH.ca / Solidworks

02-16-2009, 04:42 PM	#11 (permalink)
cpeteod 2006 elise, 2007 BMW 335i Join Date: Jun 2007 Location: New York Posts: 116	Ok let me back track. I am not trying to under or over anything. The reason i need to know what size the pully to the mm is that the size of the crankshaft pulley has a direct relationship to a supercharger RPM level. I just wanted to know what i would be pushing the supercharger to. My supercharger has a higher ratio then most supercharger do. I am doing just some simple math but need to know exactly how many mm or inches the stuipd pulley is and it is hard info to find. I thought it was 5inches (127mm). If the pulley is 123mm, that difference would mean i could rev the engine to the current fuel cut off limit. If not i have to lower the limit. Hope that explains why i just need to know what the size of the pulley is to the mm. Example: A= B * (C/D) * SUPERCHARGER RATIO (A) Im Peller speed max. (B) Engine speed max. (C) Diameter of crank shaft pully (D) Diameter of supercharger pully Last edited by cpeteod : 02-16-2009 at 04:54 PM.

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