If you have ever done your own timing belt, or helped someone else:
After you got the crank and cam gears in the correct position, and were installing the new belt on said gears, did the teeth on the belt line up with the teeth on the gears, or did you ahve to move on or move of the cam gears from "perfect" to get the belt to go on?
This question comes after doing a timing belt on my G/Fs B20A (3rd Gen Prelude). I was under the impression that the belt can gears would be properly sized and layed out so that when you installed the belt you could wrap it around the crank gear, stretch it around the exhaust cam, then around the intake cam, then snake it around the water pump and tensioner pulley, then jsut release the tensioner. During this the cams would remain "locked" in place buy putting dowels through the locking holes.
This was not the way it worked in practice. With both cams lock in #1 TDC postion, and the crank timing mark on the flywheel perfectly allighed with the pointer on the block, the belt would not go right onto all the gears. If you placed it in the teeth of the crank gear and pulled it taught to wrap it around the the exhaust cam gear, it was exactly one half pitch (tooth) off, so thusly it would not go on the gear without leaving some slack inbetween those gears. Same if I tired to wrap it around both the intake and exhaust gears, it was one half pitch off, and the lony way to get both sets of teeth to engauge was to lave a bunch of slack in between.
The solution I came up with was to point the exhaust cam in slightly towards the middle, snake the belt tightly around the crank, tensioner, water pump, intake cam (which it was able to do basically without any slack, then rotate the exhaust cam gear counterclockwise until the teeth lined up the belt teeth. This left the exhaust cam advanced a little after we did the tension adjustment.
It councerned me greatly during the install that everything did not line up "perfectly". So much so that I jumped in the internet and seached for posts where ppl may have had this experience before. I cam up with little or no help. Ray's timing belt post for 5th gens was the only one who mentioned that you may have to play with the cam gear postions and that they may not line up perfectly. And I seached on several sites including this one, AP, Honda-tech, and a Yahoo search. The shop manual made no mention of any of this either.
After all that my questions to you are:
1) So is this "not lining up" normal when doing a timing belt on A DOHC motor. Please post up your expeiences. Please mention what engine you were working on.
2) Will the engine run OK with the exhaust cam advanced slightly like it is? We ended up doin the timing belt b/c the old belt stretched and jumped time. One tooth off and it was backfiring some.
__________________ Paul
2009 Mazdaspeed3 | 1995 Miata | 1999 Crystal Blue Base - bought 6/13/02, sold 3/11/09
PS, part of the reason for making this thread it to answer this question for others in the future as well as my own curiousity. And as of now we have not tried to start the motor b/c the batter y was dead. It will be started tonight.
__________________ Paul
2009 Mazdaspeed3 | 1995 Miata | 1999 Crystal Blue Base - bought 6/13/02, sold 3/11/09
I had a tough time getting it lined up on my 5th gen - but it did eventually work the way it's supposed to. Although it was tough on the H22 'cause there's no pins to lock the gears in place.
But I found it was really dependent on exact positioning of the timing belt gear behind the crank pulley. If it was off by even half a millimeter, something wouldn't line up at some point.
Does the B20a have a TDC mark on the oil pump housing? I found that marking to be a lot more precise than the flywheel for finding exact TDC. Once I did that, everything lined up perfectly (even though it was still a b|tch to get on w/ the manual tensioner upgrade).
Of course, it may be different on the 3rd gen . . . . no personal experience there.
Is the car running as you have it now? I got my exhaust cam off by a tooth on my first try (I forget if it was advanced or retarded), and it ran like SH|T - barely started, wouldn't idle, etc. But again, might be different on a B20.
edit - was typing while you were submitting your 'PS' . . . .
I think you can go ahead & try starting it, see how it runs.
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Originally posted by Daemione Does the B20a have a TDC mark on the oil pump housing? I found that marking to be a lot more precise than the flywheel for finding exact TDC. Once I did that, everything lined up perfectly (even though it was still a b|tch to get on w/ the manual tensioner upgrade).
Thanks Dave,
I wasn't aware of a mark on the oil pump but I never looked either. The official Honda shop manual tells you to use the mark on the flywheel. But I would trust a mrk on the oil pump housing that you say lined the keyway on the crank up with over the mark on the flywheel.
__________________ Paul
2009 Mazdaspeed3 | 1995 Miata | 1999 Crystal Blue Base - bought 6/13/02, sold 3/11/09
I have a 98 h22a and have done my timing belt a couple times because of certain mods. Each time I have done it, I have found the timing belt procedure to go pretty well. I do not put the belt over the tensioner and water pump last though. The helm manual says to put it over the crank, then the tensioner, water pump, exhaust cam, then intake cam. Lastly, tighten the tensioner. This is how I did it and it works just fine.
BTW. I dont really use the flywheel mark with too much importance as stated by another member. The reason is because lining up the mark with the site on block is really dependent with your eye level. I use the oil pump mark as previously stated; it is much more accurate.
Same here, i use the mark on the oil pump also. There is a little bit of play in the belt until you release the tensioner. So you have a little bit play in the cam gear alignment. The important part is once you have it on and give it a few turns the little groves line up.
Also i do have the spots for dowels in my h22a head. There are 2 holes on each side of the bracket above he cams and each cam has one hole in it.
One funny thing is the first few times i was trying to do my timing belt i thought the T on the water pump was am arrow, so i spent all of this time lining up the water pump. haha stupid.
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AIM:ISUBIEXI
S/SI/Vtec Hybrid. RS*R Header, JDM downpipe, Custom Downpipe back 2.25 Exhaust, Intake, ""Mugen"" Programmed p13, No balancer belt, no AC, Fidanza Flywheel, ACT clutch, SI trans, Power Slot rotors, SkunkII Coilovers, Enki Rims.
Originally posted by [SUB[EX] Also i do have the spots for dowels in my h22a head. There are 2 holes on each side of the bracket above he cams and each cam has one hole in it.
Yeah, the 4th gen H22's have 'em. 5th gen's don't. No idea why - cause they sure do make things easier.
Quote:
One funny thing is the first few times i was trying to do my timing belt i thought the T on the water pump was am arrow, so i spent all of this time lining up the water pump. haha stupid.
Ha hah . . . . yeah, you wanna make sure to get that water pump at TDC.
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i wish this stupid thing would have some better freakin' directions... it never said what order the timing belt should go... it just says 'put it back together in the order in which you took everything apart' great.. thanx helms.. maybe i should go and run it by other manuals available for the 3rd gen.. some of the sections in other ones are better detailed..
i just started it.. it backfired once and i was done with it..
i think i may get started on pulling it apart again.. thank gawd i didn't put it all back together again today.. but i think i'll search for this oil pump marking and hope it exists..
fyi... this is only the 2nd time around i've messed with a timing belt... my 1st motor my mom paid for the timing belt to get done.. the swap.. my dad just told me to stay out of the way and he'd do it all.. for whatever reason.. he isn't remembering a whole lot of anything (about most things in general.. his memory seems to be fading.. old age i guess).. so he's pretty useless...
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Last edited by PreludeChick89; 06-23-2004 at 03:42 PM.
When I did mine, I didn't notice any marks on the oil pump. I just lined it up with the flywheel markings and it all worked out.
I put mine on just like dvp95 said, "The helm manual says to put it over the crank, then the tensioner, water pump, exhaust cam, then intake cam. Lastly, tighten the tensioner."
Did you look at the lines on the back side of the cam gears and see if they were lined up with the top of the head?
^^We put the belt on the crank pulley, tensioner, water pump, intake cam, exhaust cam. In that order. Rotated the crank three cam teeth, then tightened the tensioner.
The cam gears are 98% lined up. The exhaust and intake cam marks don't point exactly at each other. They are maybe 2 degrees off. When I had the gears lined up perfectly, the belt would not go on. Like I said, everything was 1/2 pitch off. Maybe I'll take pics tonight.
__________________ Paul
2009 Mazdaspeed3 | 1995 Miata | 1999 Crystal Blue Base - bought 6/13/02, sold 3/11/09
Update: I discovered that the distributor rotor came off and had spun 180 degrees from where it should be. That explains the backfiring. The engine now starts, but runs very rough and tries to shut off. We are gonna re-do the timing belt this weekend.
Since her engine is a JDM one the USDM dist. rotor I bought at autozone does not work. Anyone know where we can get the JDM one FAST?
__________________ Paul
2009 Mazdaspeed3 | 1995 Miata | 1999 Crystal Blue Base - bought 6/13/02, sold 3/11/09
my helms never mentioned what order the timing belt goes on either... the god damn thing will not line up for **** no matter what the **** we do... i'm so frustrated...
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