Tdc

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Speed Box

New Member
For the block.....

From the first pic with No1 cylinder up like that its TDC right?

Why is that little D is off to the side thou?

For the head the cam just has to point UP to the up and thats it what I think.
 

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Thanks for the link! I think its the Helms manual. right?. Because I was using Haynes manual and its not very clear actually they had a pic with cylinder No2 and 3 were up and they were talking about tdc.

In the manual it mentioned Up is UP? for the cam gear. Its under 'position crackshaft before installing timing belt'.

I know what you mean, that up is not really up because I read somewhere that up is more like to the side at 7 o'clock.

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Set the block tdc, set the head tdc, bolt the head down, slide the belt on cam and hopefully car starts.
 
I have to actually try it a few times to actually understand this TDC. Right now I'm totally lost.
 
I think I have to take off dist cap. and mark rotor to point to number 1 cylinder.

With cam pointing up.

With No1 cylinder piston all the way up.

So the "cam" has to match the "head" has to match the "block" ?

I'll search this TDC try to figure it out.
 
I lined up the marks like blanco said(on the block). Then you have to make sure that when you are looking down on your engine on the right driver side You see a plastic V line up with a point. These two lined up whould line up with a groove on the cranck pully. Now to line up your dizzy I would like to tell you how but I cant explai. If you need more help I can maybe post some pics later.
 
TDC, Top Dead Center, is when the piston is at the exact top on the compression stroke - on the 4 cycle engine, the crankshaft rotates 2 times for each cycle of the engine - each of the pistons reach TDC on the compression stroke and again on the exhaust stroke - due to the layout of the engine, #1 and #4 are at TDC at the same time - when #1 is up on compression, #4 is up on exhaust and conversely when #4 is up on compression, #1 is up on exhaust - at the same time, #2 and #3 are at BDC or bottom dead center, one on intake and the other on power - the camshaft(s) rotates one time for each cycle of the engine, thus the gear on the camshaft which is exactly twice the diameter of the gear on the crankshaft - when both of the #1 and #4 pistons are at TDC, the mark on the crank pulley will align with the mark on the timing cover - when it is at TDC on compression on #1, the "UP" on the cam gear will be generally up - when it is at TDC on compression on #4, the "UP" on the cam gear will be 180 degrees off, or generally down - you don't need to worry about the distributor as the camshaft has the slot that the distributor shaft fits into offset so that the distributor will only go on one way - when you put it on it will automatically be in the correct position - do not use the manual that was linked to in one of the posts above if you have a USDM car with a D16A6 engine - that manual is for the cars in the UK - in the US, the 88-91 D15 engines camshafts are not lined up the same as the 88-91 D16A6 engines - with the D15 engine, you align the marks on the cam gear with the top of the head - with the D16A6, you align the third mark on the cam gear, which is at about 7 o'clock, with the pointer on the inside timing gear cover
 

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