3mm crank, no spacer plate. metalic tapping noise?

[Outlawed Genetics]

so i bought this top end off a member here that was supposed to be setup for a 3mm crank without the spacer plate that comes with the crank but it makes this metalic toapping noise like either the rings are catching on something or the piston is hitting something. if the guy i bought it from was mis informed and it isnt ported and setup for a 3mm crank with no spacer plate would it just not run? or would it do what i described above?

 

[phragle]

thats probably the piston smaking the head. did you get the head or just the cylinder? is it setup for the thick or thin base gasket?

 

[Outlawed Genetics]

got the cyl and head. as for base gasket size he never said and i didnt know there were 2 different ones so i used a regular one. how would i tell if the cyl/head is setup and ported to match the 3mm crank? i also have the spacer plate but was told i woudlnt need it with this kit.

 

[speedracinshift]

it sounds like u may have too run the plate like stated above sounds like your pistion slapen the head.

 

[Outlawed Genetics]

wish i could talk to the guy more about it he seemed like a great guy and went the extra mile to help me with some other stuff but cant contact him he joined the army or something. can anything go wrong if i put the plate on and dont need it?

 

[phragle]

simple, take your dial indicator and stand measure your deck height and see if the head has been cut accordingly. or if you lack finer tools, put a thin layer of clay in the squish band, tighten up the head kick it over, pull the head and measure.

 

[phragle]

wish i could talk to the guy more about it he seemed like a great guy and went the extra mile to help me with some other stuff but cant contact him he joined the army or something. can anything go wrong if i put the plate on and dont need it?

It will just drop the compression a bit.

 

[Outlawed Genetics]

simple, take your dial indicator and stand measure your deck height and see if the head has been cut accordingly. or if you lack finer tools, put a thin layer of clay in the squish band, tighten up the head kick it over, pull the head and measure.

i've got digital calipers but thats about it. i know im useless but i have no idea how to measure deck height.

 

[OConnor Racing]

You need to check a few things. First is the head gasket. I'm going to assume that because you have no plate, you have positive deck height(the piston is coming out of the cylinder). You need to make sure the inside diameter of the gasket is larger than the piston. If it's not, you need to open the head gasket up. If all of this is good, check the squish. Take a piece of solder wire and bend it into the spark plug hole so that it lines up with the crankshaft center line. Make sure the solder is at the end of the bore and turn the engine over slowly with the kicker or the flywheel. Take the solder out and measure the compressed thickness. Should be about .045” thick. This should find the problem. PM me if you have more questions.

 

[Outlawed Genetics]

You need to check a few things. First is the head gasket. I'm going to assume that because you have no plate, you have positive deck height(the piston is coming out of the cylinder). You need to make sure the inside diameter of the gasket is larger than the piston. If it's not, you need to open the head gasket up. If all of this is good, check the squish. Take a piece of solder wire and bend it into the spark plug hole so that it lines up with the crankshaft center line. Make sure the solder is at the end of the bore and turn the engine over slowly with the kicker or the flywheel. Take the solder out and measure the compressed thickness. Should be about .045” thick. This should find the problem. PM me if you have more questions.

im sure this sounds retarded but wheres the crankshaft center line? how would i find that? the rest i understand.

 

[Outlawed Genetics]

i should also add it did this first when i put it togather with this top end and a 4deg timing advance. it stopped when i put a stock timing key in for the short time i rode it, then today i noticed a gap between my pipe and cyl and replaced that ring gasket and tightened the pipe down and now its doing it agian so could this also be a gas problem related to compression?

 

[mystahagy]

This is a little off the wall, but see if you have those rubbers between the fins on the cylinder and head. The topend sounds much worse without them.

 

[stephen12091985]

sounds like you need the spacer plate.when i first put mine together i didnt put the spacer plate and my piston hit the head and i took it back apart and put the spacer plate and it was fine

 

[Kennedy_Power]

You need to check a few things. First is the head gasket. I'm going to assume that because you have no plate, you have positive deck height(the piston is coming out of the cylinder). You need to make sure the inside diameter of the gasket is larger than the piston. If it's not, you need to open the head gasket up. If all of this is good, check the squish. Take a piece of solder wire and bend it into the spark plug hole so that it lines up with the crankshaft center line. Make sure the solder is at the end of the bore and turn the engine over slowly with the kicker or the flywheel. Take the solder out and measure the compressed thickness. Should be about .045” thick. This should find the problem. PM me if you have more questions.

Ken Negative deck height is the piston out of hole... Squish clearance depends upon the size of the piston and connecting rod strength.

 

[motoman9911]

Positive deck height is the piston in the hole.

 

[Brute71]

it could be detonation, try some higher octane gas and see if that fixes it.

One way to see if the piston is hitting the head is to see if the piston is shaped to the head (it will be effectively beaten to fit).

 

[Kennedy_Power]

negative deck height is the piston out of the hole

 

[OConnor Racing]

The PISTON Deck Height is the distance the piston EDGE is in relation to the top of the cylinder deck. NOTE: This
distance can be negative (the piston edge is recessed in the cylinder deck) or positive (the piston edge is sitting above the cylinder deck).

 

[Outlawed Genetics]

added the spacer plate today and lost some power but also lost some of the noise. the tapping is still there but its less noticable.

 

[Outlawed Genetics]

could this noise be caused by the 3mm crank hitting the edges of the case or something? it was supposed to be a drop in but i just saw on another thread that they may require some fitting. would be nice if that was the problem and i could lose this spacer plate and get my power back. had alot more power without the plate. supposed to be going riding tomorow i'll try to remember to get a vid of the noise.