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reverse rotation timing sprockets / gears

Posted: Wed May 08, 2013 4:37 pm
by 1995 390 express
would anyone know of any video or printed pics. of what the timing gears should look like when properly installed on a 454 reverse rotation engine. should they be flush or does one stick out an 1/8 inch more than the other and has anyone heard what noise they might make. just installed reground crank and .10/.10- bearings. motor fired up with 2 clicks of the starter and there was an instant mechanical clicking noise. pulled engine drained oil - no metal in the pan. the only mechanical changes were the oil pump and swapping the crank shaft gear. i removed tranny -bell housing-front cover harmonic-pulleys -water pump etc and there is no sign of anything hitting.this noise was not there when motor was pulled and wear marks on gears seem strange to me. do gears make any noise versus a what a chain would sound like ? thanks for any opinions

Re: reverse rotation timing sprockets / gears

Posted: Wed May 08, 2013 4:52 pm
by Stripermann2
Gears will tend to whine as opposed to a chain driven set-up. How about the push rod for the fuel pump...was it clicking...?

Re: reverse rotation timing sprockets / gears

Posted: Wed May 08, 2013 5:09 pm
by 1995 390 express
no mechanical fuel pump - just electic. thank u for input- would like to hear as many possabilities as i can before i tear it completely down.

Re: reverse rotation timing sprockets / gears

Posted: Wed May 08, 2013 8:15 pm
by mikeandanne
Which sprocket is sticking out further?--- in my opinion those gears should mesh even--- make sure the crank sprocket is the same thickness and is seated on the crank correctly--- also check that cam is not being interfered with by the oil drive gears--- those engines just have a distinctive whine like was previously mentioned---all I can think of with out seeing it---Mike

Re: reverse rotation timing sprockets / gears

Posted: Wed May 08, 2013 9:02 pm
by Diverted Income
Not a solution, but cut the filter open and see what is in it. May give you a clue.

Re: reverse rotation timing sprockets / gears

Posted: Wed May 08, 2013 10:50 pm
by mikeandanne
Check this, I tried to make it smaller???? does this resemble yours??Mike

Re: reverse rotation timing sprockets / gears

Posted: Thu May 09, 2013 5:39 am
by 1995 390 express
thank you -yes thats it exactly. crank gear seems to be out an eighth inch or less. that is the only gear that was swapped. cam and gear never were removed. how would i seat it correctly - HEAT ? and it they are not meshing properly would i get the clicking noise versus a whine. great pic thanx again

Re: reverse rotation timing sprockets / gears

Posted: Thu May 09, 2013 7:43 am
by mikeandanne
If it were me I would compare the new gear with the old with calipers, sometimes just .001" difference in size of crank snout and gear could alter the way they fit together.---- can you put old gear back on and why was it changed???---- as to the clicking ,would have to hear it---- also is that crank your old one reground or different-----did the old gear come off with just hands or persuasion--can you put old gear back as they may need to be a matched set ???--- Lot's of questions I know but there are many things to check---- if you are talking heating any parts ,do not use torch ,just put in oven .---- all I can think of --- Mike

Re: reverse rotation timing sprockets / gears

Posted: Thu May 09, 2013 7:52 am
by Stripermann2
mikeandanne wrote:If it were me I would compare the new gear with the old with calipers, sometimes just .001" difference in size of crank snout and gear could alter the way they fit together.---- can you put old gear back on and why was it changed???---- as to the clicking ,would have to hear it---- also is that crank your old one reground or different-----did the old gear come off with just hands or persuasion--can you put old gear back as they may need to be a matched set ???--- Lot's of questions I know but there are many things to check---- if you are talking heating any parts ,do not use torch ,just put in oven .---- all I can think of --- Mike
Mike is on to something here. The crank was changed...the forward end of crank snout has a different machining than the original. Also, GM changed over to plastic timing covers, what year, I'm not sure but there were clearance issues as well if you had the wrong cover. Most timing sets require this info to be sure you have the correct set. If you find the crank to be the issue, you may be able to pull crank gear and have a machine shop mill down enough to match.

Re: reverse rotation timing sprockets / gears

Posted: Thu May 09, 2013 4:22 pm
by 1995 390 express
thanks for all the advice - yes the crank was from another motor i had sitting in garage--gears are a match set from the engine which was running last year. the gear that is sticking out is the crank gear put on by us. all the parts were on and running last year with no noise so i assume timing cover and all are correct. there was no sign of any ware or rubbing on anything. does the harmonic balancer push up against the crank gear to hold in place or is there a space between. complete engine was a rebuilt last year- had a oil pressure problem and had a bearing rap. that was the reason for the crank and bearing replacement. the clicking noise appeared to be from the front of engine with stethoscope but i know noise travels plus im deaf as a haddock. if balancer butts up against gear it should of been in correct spot and im looking in wrong direction. if you come up with anything else im still listening but tomorrow ill mic both cranks and check where the gear sits. if i don t find anything ill pack up engine -both cranks and head to machine shop. thanx again

Re: reverse rotation timing sprockets / gears

Posted: Mon May 27, 2013 8:38 am
by 1995 390 express
engine is all set- in the boat and running great. it turns out that when i installed the crank we had the gear on so we could drop it in on the correct timing as the engine was still all together. when setting it in we had to be careful not to damage it while lining up the mains and the 8 rods. while meshing the gears together at the same time 3 of the teeth got the slightest damage that you could barely see with the naked eye. a couple of strokes of a file and the nasty noise is gone. live and learn lol. thanks again for all the advice

Re: reverse rotation timing sprockets / gears

Posted: Mon May 27, 2013 1:01 pm
by mikeandanne
Good to see the end result all worked out ok.---seems like it is the small stuff more often than not----I have changed cranks etc a few times with engines all together,Lot's of fun heh, usually takes about 8 hands and 6 eyes to keep everything ok. ---Mike