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Topic: timing chain and pan drop questions

in Forum: C3 Engines


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timing chain and pan drop questions (13/23)
 9/6/10 10:54pm
jp75vette
Former Member

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Bloomfield Hills, MI - USA

Vette(s):
1975 Corvette coupe, 4 speed manual, 383 ci 9.5:1,Edelbrock dual plane Air Gap intake, Alum Heads,Comp Cam, roller Rockers, PS,PB,Tilt


Joined: 6/29/2008
Posts: 199

when you go for a new oil pan gasket; the one piece Felpro's work great.
timing chain and pan drop questions (14/23)
 9/7/10 12:24am
daveo76
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Vancouver, WA - USA

Vette(s):
1976 Silver/Firethorn. L48, 4spd. Original 2 bolt, vortec heads, 9.4:1 CR, Speed Pro Cam: 224/224@0.050, 112 LSA, Eagle Steel Crank.


Joined: 8/25/2005
Posts: 857

Re: the debate about 12/12 or 12/6: In the other thread someone came to the conclusion that it doesn't really matter -- either one works.  If both of mine were at 12:00 and I rotated the cam to 6:00, #1 is still on TDC, but it would simply "change" to the exhaust stroke from the compression stroke. (And I am sure it was on compression when I took everything apart) It becomes more complicated for me, though, as my distributor (and manifold) is out as well.  If I rotated my cam 180 degrees now, I would have to install the dist exactly 180 out when I put it back in.  So I'm going to line up the new timing set with a straightedge as Joel says and hope I get it right.  If the distributor were in, rotating the cam would take care of rotating the dist and everything would be fine.  Anyway....

So since I have my oil pan off I guess I should replace the oil pump as well?  How often do those fail? Engine has about 75K miles on it.   I was looking at Advance Autoparts and it looks like I could get a Melling high volume pump for about $30 or $40.  


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1976 Silver/Firethorn.  L48, 4spd.  Original 2 bolt, vortec heads, 9.4:1 CR, Speed Pro Cam: 224/224@0.050, 112 LSA, Eagle Steel Crank.
timing chain and pan drop questions (15/23)
 9/7/10 12:25am
daveo76
Former Member

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Vancouver, WA - USA

Vette(s):
1976 Silver/Firethorn. L48, 4spd. Original 2 bolt, vortec heads, 9.4:1 CR, Speed Pro Cam: 224/224@0.050, 112 LSA, Eagle Steel Crank.


Joined: 8/25/2005
Posts: 857

Yep, already got the one piece Felpro - seems like it'll be a lot easier than the older four piece things...

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1976 Silver/Firethorn.  L48, 4spd.  Original 2 bolt, vortec heads, 9.4:1 CR, Speed Pro Cam: 224/224@0.050, 112 LSA, Eagle Steel Crank.
timing chain and pan drop questions (16/23)
 9/7/10 8:50am
yostusota
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York, PA - USA

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1969 daytona conv. all original 350 350 380 4 sp w/air..and hard top


Joined: 5/18/2010
Posts: 1518

Well its Tuesday morning! I would replace the pump if you have it taken apart as far as you do..when you pick up the pump see if it has that plastic line up collar for the pump to shaft..those do fall apart at times...and a pump gasket..maybe since this is so far apart you could do the plugs and wires like Ebo! Is that gasket a neoprene style or cork..oil pan gasket? Cork worked good if you glue it on with that black airplane glue.. I like the neoprene though..I will let the gear thing die because it really doesn't matter unless you are trying to line up the distributor.
Rich




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My first parade at Carlisle 2010
timing chain and pan drop questions (17/23)
 9/8/10 2:05am
daveo76
Former Member

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Vancouver, WA - USA

Vette(s):
1976 Silver/Firethorn. L48, 4spd. Original 2 bolt, vortec heads, 9.4:1 CR, Speed Pro Cam: 224/224@0.050, 112 LSA, Eagle Steel Crank.


Joined: 8/25/2005
Posts: 857

I think my original pump still has the collar (there's an orange sleeve thing on the shaft) but I'll probably get all new stuff.  Plugs and wires should be OK now, but I do agree having all this stuff off would make that job much easier.  The one piece Felpro is not cork and I don't think it's neoprene, either.  It's a blue rubber material on the outside, but it has some type of rigid spine inside.  The bolt holes have metal reinforcements.  I've talked with a few folks now that recommend them.  

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1976 Silver/Firethorn.  L48, 4spd.  Original 2 bolt, vortec heads, 9.4:1 CR, Speed Pro Cam: 224/224@0.050, 112 LSA, Eagle Steel Crank.
timing chain and pan drop questions (18/23)
 9/9/10 11:28am
VetteSpecialties
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Mounds View, MN - USA

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70 LT1 coupe, 69 350 HP coupe, 69 390HP 427 coupe, 71 LS5 convert, 85 coupe, 93 coupe


Joined: 5/24/2007
Posts: 1031

Back to the 12/6 debate.  If you do not remove your distributor, it doesn't matter at all which way you line up the marks.  The cam runs a half the crank speed, and the distributor runs off the cam.  It is correct that if you put the cam at 12:00, #1 will be on the top of the exhaust stroke rather than the firing position, but the distributor has turned with it, so # 6 will be firing.  The only time you need think about firing is if you take out the distributor, in which case you need to start over and turn the engine to #1 firing before reinstalling the distributor.

Larry
timing chain and pan drop questions (19/23)
 9/10/10 12:16am
daveo76
Former Member

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Vancouver, WA - USA

Vette(s):
1976 Silver/Firethorn. L48, 4spd. Original 2 bolt, vortec heads, 9.4:1 CR, Speed Pro Cam: 224/224@0.050, 112 LSA, Eagle Steel Crank.


Joined: 8/25/2005
Posts: 857

I agree, but my distributor IS out. 

Distributor rotor was pointing close to #1 when I took the distributor out.   When I took the balancer off, it was pointing at TDC.  When I got the timing cover off, both marks were at 12:00.  I am sure everything is factory - it doesn't look like anything has ever been touched since it left St. Louis.  Is it possible some engines were built with both marks lined up with #6 (NOT #1) at TDC on compression? From reading the other thread it sure sounds like some manuals say it is one and others say it is the other.   Well, my plan is to put everything back the way I found it.  I won't rotate the cam, unless it is for a one or two tooth adjustment, and I'll put the distributor back in so the rotor is at #1.  Sound kosher?  This is kind of an interesting debate, though..... 


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1976 Silver/Firethorn.  L48, 4spd.  Original 2 bolt, vortec heads, 9.4:1 CR, Speed Pro Cam: 224/224@0.050, 112 LSA, Eagle Steel Crank.
timing chain and pan drop questions (20/23)
 9/10/10 5:59pm
nosal1
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Dunedin, FL - USA

Vette(s):
1980 Corvette Torch Red with Gold metallic 370HP/350 CU.IN.Turbo 350 w/shift kit.Originally CA.Car with 305 CU.IN.


Joined: 3/21/2006
Posts: 262

 
Good Afternoon All,
 
       If you go to You Tube and type in the head line below you will see DVD of a timing chain/gear installed as it has been done since 1965 on Chevy engines..It always set 6 o'clock position for the cam gear and 12 for the crank gear, this is top dead center #1 when you rotate 180 degree you are now at #6 firing.....
 
       Take care all,
           Sal C
 
     
 
 
[YOU TUBE]  CHEVY ENGINE REBUILD CAMSHAFT TIMING CHAIN INSTALLATION DVD
 
 
 
 
 
timing chain and pan drop questions (21/23)
 9/10/10 7:53pm
nosal1
Former Member

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Dunedin, FL - USA

Vette(s):
1980 Corvette Torch Red with Gold metallic 370HP/350 CU.IN.Turbo 350 w/shift kit.Originally CA.Car with 305 CU.IN.


Joined: 3/21/2006
Posts: 262

                Sorry All,
                                 Statement should read,   "has been done since 1965 on",
         Sorry for the typo...
 
Sal C
timing chain and pan drop questions (22/23)
 9/10/10 7:56pm
nosal1
Former Member

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Dunedin, FL - USA

Vette(s):
1980 Corvette Torch Red with Gold metallic 370HP/350 CU.IN.Turbo 350 w/shift kit.Originally CA.Car with 305 CU.IN.


Joined: 3/21/2006
Posts: 262

              Sorry All,
                                 Statement should read,   "has been done since 1955 on",
         Sorry for the typo...
 
Sal C
      PS: A correction for the correction..It's been a long day!!!!!
timing chain and pan drop questions (23/23)
 11/5/10 10:18pm
daveo76
Former Member

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Vancouver, WA - USA

Vette(s):
1976 Silver/Firethorn. L48, 4spd. Original 2 bolt, vortec heads, 9.4:1 CR, Speed Pro Cam: 224/224@0.050, 112 LSA, Eagle Steel Crank.


Joined: 8/25/2005
Posts: 857

I solved my problem by installing the intake manifold and then distributor first and THEN doing the timing chain stuff.  I put the dist in exactly the way I took it out and then was free to rotate the engine so the marks align at 6 and 12.  Then I took the old gear off and put the new stuff on.  BUT...with the marks at 6 and 12, the dist rotor points at the #6 cylinder position, NOT #1 telling me that the engine is set at TDC with #6 on compression, not #1 (#1 is at TDC, exhaust).   

I'm not saying that engines were ever put together with the marks not aligning at 6 and 12 (I'm sure they were), but I am theorizing that there were some differences regarding whether #1 or #6 was set at TDC, compression.  Even my own Haynes manual has a discrepancy - the text says #1 and the picture caption says #6.  


______________

 

1976 Silver/Firethorn.  L48, 4spd.  Original 2 bolt, vortec heads, 9.4:1 CR, Speed Pro Cam: 224/224@0.050, 112 LSA, Eagle Steel Crank.
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