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Valve timing

SargeVT

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I am still searching for the backfire through the carb problem on my '67 BJ8. Today I am after the valve timing as some of you suggested. I have removed the radiator, the valve cover, plugs and fan belt. When No.1 is TDC which other valves should be closed? If one of the sprocket is off one or two teeth I guess I will pick it up when I pull the timing gear cover so maybe the question is irrelevant. Hope the balance wheel comes off easy!
 
Hi Sarge,
You can use the rule of 13 to set the valves.
Numbering the valves from front to back, when valve # 1 is fully open adjust valve # 12 (13 - 1 = 12)
With # 2 fully open adjust # 11 (13 - 2 = 11)
With # 3 fully open adjust # 10 (13 - 3= 10)
And so on. Use the rule of 9 for a four cylinder.
D
 
Hi Sarge. With N0 1 At TDC #1Valves and #6 should be rocking. With the timing chain cover removed the Crank shaft keyway and the Cam shaft key way should both be at 12 oclock.On the right hand side of the timing chain You should count 15 LINKS DOT-to-DOT.---Fwiw---Keoke
 
Thanks for the quick response. The info is just what I needed.

I tried to take the big nut off the balance wheel on the front of the engine but she didn't bugge. Didn't try too hard because I wasn't sure if it turns clockwise or counerclockwise viewing from the front. I think it is counter?
 
HI Sarge, The simplest way to get that nut off is to use an impact wrench with at least 240lb/ft torque. Also in my earlier response "Rigt hand" means your right when viewing the front of the engine,--Fwiw---Keoke
 
Hello Sarge,

a quick check for correct valve timing (in most engines) is with no 1 cylinder at TDC firing, then valves 11 and 12 (7 and 8 on a four cylinder) should be rocking, i.e. one closing as the other opens. At TDC they both should have equal lift.
This is easily checked if you have a dial indicator or by backing off the valve adjusters to a nominal figure, say 5 thou then checking the actual clearance, which should be the same for both inlet and exhaust if they have the same setting or different by the variation in valve clearance settings.

Alec
 
Keoke,
Thanks for the advice on the air wrench. I'll have to pick up a 1-11/16 " socket in the morning. I'm guessing "righty tighty-lefty loosey" on the nut.

Alec,
If the the chain were off only one tooth, would I still be able to pick it up with an indicator on 11 and 12? Have never done it this way before so would like to try it!

Sarge
 
Keoke,
After getting a socket, I used your suggetion of the air wrench. Nut came off like a piece of cake! Thanks for the info. The balance wheel and pulley slide off until it got to the cross member or strut tower brace and then stopped - no room. Now I will get a gauge and check the timing as Pinman suggested. If I find valve timing off, I guess I have no choice but to pull the engine.
 
/ubbthreads/images/graemlins/savewave.gif
No No Sarge, do not pull the engine. Just unbolt the Motor Mounts from the frame and jack the engine up a bit. Put a good stong piece of wood between the Oil Pan and the Jack saddle and you will be home scott free. OH ! make certain that you have flex joints between the down pipes and the mufflers or loosen the pipes at the manifold ---Fwiw ---Keoke /ubbthreads/images/graemlins/yesnod.gif
 
Hello Sarge,

yes, one tooth is a large discrepancy, and would show up.
Please note that this is not the normal way of timing a camshaft and the sure way is to follow the manufacturers recommendation. The trouble is that this information is only normally available for after market camshafts. The normal instruction in a workshop manual is to line up timing marks.
Perhaps others who have specific knowledge of Austin Healey engines would like to comment.

Alec
 
I have already given Sarge the correct methods for the Healey engine Piman. Plus Healeys are not your normal engine---Keoke /ubbthreads/images/graemlins/laugh.gif
 
Hello Keoke,
yes, I noted that, but it entailed the removal of the timing cover. For engines with symetrical timing the method I mentioned is the quickest.
I do not understand what you mean when you say Healeys are not your normal engine, what is normal? Certainly they are conventional and pretty basic.

Alec
 
I do not understand that healeys are not your normal engine: To wit: the timing dots do not line up adjacent to one another as is the case in a normal engine,Piman.---Keoke
P.S. Stock Healey cam gears do not include any adjustment.You must have good gears and a good chain. /ubbthreads/images/graemlins/yesnod.gif
 
Hello Keoke,

thank you, I now understand the reference to the 15 links. Different designs with different arrangements!
Jaguar has one of the easiest timing methods on the XK engine, very simple with fine adjustment of the cam wheels and a simple setting tool to align the cams.

Alec
 
I unbolted the motor mounts as Keoke recomended and was able to jack the engine enough to get the balance wheel off easily. The hardest part was getting at the lefthand side bolts because of the manifold pipes and the SUs. After removing the timing chain cover I found 15 links from DOT to DOT as Keoke said I should. The curious part is the DOT on the timing gear is at 6 o'clock ( I thought it was supposed to be at 12 o'clock)when the key on the crank is at 12 and #1 is TDC on compression stroke. Both rockers had clearence. #6 on the other hand did not follow as PIMAN said they should. The rockers were still tight - no clearence. What can I deduce from this? Seems somethin ain't right!
 
Hi Sarge, If the Dot on the gear on the crank shaft is at 6 oclock and the Dot on the Cam shaft gear is at approximately 1 oclock and there are 15 Links DOT-to-Dot that is correct. I made an error there. However, both shaft key ways must be at 12 oclock---Keoke
 
When I first got my BJ8, it would backfire through mostly the rear carb every time I gave it some gas. After checking the valves and carbs, I replaced the old coil and points with the Petronics ignition pickup and matching coil. The backfires were 100 % gone after that.
 
Hello Sarge,

you need to re-read what I said, 11 and 12 should have equal lift so they will be tight.
Another way of checking is to rotate the engine back and forward noting where the valves just start to open (valve clearances must be set to spec)The distance either side of TDC shold be equal. You will need to turn the crank in it's forward direction only to do this check or the backlash will throw the check out.

Alec
 
[ QUOTE ]

A quick check for correct valve timing (in most engines) is with no 1 cylinder at TDC firing, then valves 11 and 12 (7 and 8 on a four cylinder) should be rocking, i.e. one closing as the other opens. At TDC they both should have equal lift. Alec

[/ QUOTE ]
Hi Alec,
As you said for "most" engines. The 3000 series Healeys Have non-symetrical cam timing. Around TDC on the overlap stroke, typical timing for the MK3, has the Intake opening 16 degrees BTDC & the exhaust closing at 21 degrees after TDC. Both intake & exhaust have the same 252 degrees duration. So they are not symetrical or as sometimes called, split overlap on the TDC non-firing stroke, & there won't be equal lift. Earlier cams have less duration but the five degree shift is still incorporated.
D
 
Hello Dave,

that's life, I did mention in one post it only worked for symetrical timing. I also said that it is not the normal way to time but it is a very easy check and will indicate, even with assymetric timing if you have a serious valve timing issue or not.
As for different ways of marking the valve train for assembly, I once owned a car which had no markings at all. Valve timing was done on valve lift with a dial indicator at TDC.

Alec
 
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