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Discussion Starter #1
Ok, so, i got my new cam for the Y7 the other day, and have gone to install it. Its a very big cam, the Bisi level 3. As i am tightening the rocker assemby down, the cam becomes tighter to turn. This im guessing is what should happen with a big cam and up rated valve srpings.

The problem is, i can get it to go round enough to open one set of valves then it jus seems to get stuck...

Where should i be looking for binding, and what could posssibly cause this? As it opens one set of valves, i should operate them all correctly, so i cant see what might be wrong....

Help me out, please.. i need this engine to go in next week!
 

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Does a lobe hit the head casting like the Crower Stage 3 on a y8 does ?
 

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Discussion Starter #3
Does a lobe hit the head casting like the Crower Stage 3 on a y8 does ?
No, i made sure i spun the cam round without anything else botled on. There is only very slight clearance between the lobes and head, but there is clearance. So that shouldnt be a problem.

It just seems strange that it will open some valves and then see to get stuck. if i try and turn it by the cam pulley bolt, it willl just start to tighten the bolt...
 

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tighten the bolts in the right order and style.....try finger tightening the bolts in the right order than using quarter turns on each bolt till its all tq'ed down.....had this prob when just puttin mine back in......if the timing belt is on it will sit cock-eyed.....just play with it a while
 

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if i try and turn it by the cam pulley bolt, it willl just start to tighten the bolt...
First, your turning it the wrong way.......

Is the head on the car and in time?
 

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Discussion Starter #8
First, your turning it the wrong way.......

Is the head on the car and in time?

If i turn it the other way it starts to un-do the bolt, so either way isnt realy possible, untill i see what happens by using something other than the bolt to turn it.

THe engine is on an engine stand, as im just trying to put it back together, i am using an old headgasket just to check clearances etc. SO the head can be either on or off the engine...
 

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Brokedick Millionaire
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put engine @ 90 degrees BTDC on #1, set cam at TDC, bring crank to TDC and install the timing belt.

DO NOT use the cam bolt to turn the eninge over....snap one and you'll see why....
 

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Discussion Starter #10
put engine @ 90 degrees BTDC on #1, set cam at TDC, bring crank to TDC and install the timing belt.

DO NOT use the cam bolt to turn the eninge over....snap one and you'll see why....

Ill have a look into doing that. And i know what you mean about the cam bolt, i didnt like turning it that way, but couldtn move it by hand..!

I think i might have found the problem though. It looks like the valve spring is binding..too much lift. Although i cant work out why it manages to get as far as it does without any problems before it stops..
 

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yea you really shouldn't turn your head by the camgear bolt, it could snap, plus our motors go counterclockwise, so if you were turning it by the bolt you should also be loosening the damn thing, not tightening.

i found it hard to turn the camshaft when the head is off the block as well.

bestway to do it is when the head is on the block with the timing belt.
 

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Discussion Starter #12
yea you really shouldn't turn your head by the camgear bolt, it could snap, plus our motors go counterclockwise, so if you were turning it by the bolt you should also be loosening the damn thing, not tightening.

i found it hard to turn the camshaft when the head is off the block as well.

bestway to do it is when the head is on the block with the timing belt.
I was doing it with the head on and belt on. I didnt dare do it particularly hard when it went solid. I took the rocker assembly off again and had a check over it. Thats when i noticed where the lobes had been catching the rocker arms!

Only on the exhaust side though. So i took it apart and did some modifying and no i think it should be ok!
 

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it sounds like your timing is off your hitting valves to piston check your crank timing if thats good double check the springs and cam part number to make sure they are the right ones for your application but dont turn the motor by the cam bad ! no no
 

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Discussion Starter #14
it sounds like your timing is off your hitting valves to piston check your crank timing if thats good double check the springs and cam part number to make sure they are the right ones for your application but dont turn the motor by the cam bad ! no no

I thought vlave to pistons to start with, but after looking at the rockers, then modifying them slightly where they were hitting the lobes, all is fine!

And i was only trying to turn the head, without the cambelt by the cam bolt, it was the last act of a desperate man im afraid!

But now this problem is over, its just about ready to go in the car!
 

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I thought vlave to pistons to start with, but after looking at the rockers, then modifying them slightly where they were hitting the lobes, all is fine!

And i was only trying to turn the head, without the cambelt by the cam bolt, it was the last act of a desperate man im afraid!

But now this problem is over, its just about ready to go in the car!
how did you modify the rockers?
 

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Discussion Starter #16
Well, first off, i dont know all the technical names for each orea of the rocker, so bare that in mind!

The part that rests on the lobe, which it pushes up and down wasnt a problem, but as the lobe carried on psat there, toward the exhaust side, it was just catching on thelarger part of it.

So it was the part around where the rocker slides onto the shaft. With a little bit taken off there, it gave enough clearance for the lobes to go past. Didnt need a great deal taken off really.

Sorry if that sounds vague, but like i said, technical terms are eluding me at this point!
 

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ok cool...i just thought you might have done something outrageous like took a grinder to the lobe contact patch of the rocker

I can picture what you mean now though on modifying the rocker to make up for the extra travel. That would completely justify the binding, good job :)
 

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Well, first off, i dont know all the technical names for each orea of the rocker, so bare that in mind!

The part that rests on the lobe, which it pushes up and down wasnt a problem, but as the lobe carried on psat there, toward the exhaust side, it was just catching on thelarger part of it.

So it was the part around where the rocker slides onto the shaft. With a little bit taken off there, it gave enough clearance for the lobes to go past. Didnt need a great deal taken off really.

Sorry if that sounds vague, but like i said, technical terms are eluding me at this point!
Please forward this info to Bisi, incase I forget.
 
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