 914 V8 timing question, How to find TDC |
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| jmmotorsports |
 Apr 5 2007, 09:22 PM
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#1
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Member  Group: Members Posts: 308 Joined: 15-August 06 From: Kelso,Wa. Member No.: 6,658 Region Association: Pacific Northwest  |
Since there are no timing marks on the balencer I figured I could use the valves to find TDC. I have a stop in #1. #1 Both valves are closed. #8 both valves are closed. #4 exhaust is closed,intake is about 1/2 open. I am thinking that should be TDC on #1. Fireing order is 1 8 4 3 6 5 7 2 Can any of the chevy experts out there tell me if I am right or wrong or if there is a better way to do it.
Thanks, Jerry |
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Replies(1 - 9)
| skline |
Apr 5 2007, 09:30 PM
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#2
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Born to Drive Group: Members Posts: 7,910 Joined: 26-December 02 From: Costa Mesa, CA Member No.: 17 Region Association: Southern California |
I would mark the flywheel with the timing cover off, when both valves are closed on number 1 in the compression stroke and the marks line up on the timing gears, you mark the flywheel so it can be seen on top of the transmission hole. That is just how I do it. Others may have a different way?
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| jmmotorsports |
Apr 5 2007, 09:37 PM
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#3
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Member Group: Members Posts: 308 Joined: 15-August 06 From: Kelso,Wa. Member No.: 6,658 Region Association: Pacific Northwest |
The engine is in the car so the gears are no help now. I will put a timing mark on when I am sure it is at TDC
Thanks, Jerry |
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| drive-ability |
Apr 6 2007, 12:24 AM
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#4
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Senior Member Group: Members Posts: 1,169 Joined: 18-March 05 From: Orange County, California Member No.: 3,782 |
If you have your piston stop in place (TDC) make a mark, then rotate the engine in the opposite direction until it stops again and mark that spot. Between the two marks is TDC. There is as you know and can likely feel a few degrees between the pistons up turn and down turn. This way gets it closer. The truth is time it as far advanced as you can without feeling it whiplash when starting. Normally thats going to get you where you want to be. I know, you really want to know down the the last degree, truth is most pointers are just indicator's at best. Race motors a different story... thats my take on this, I'm no expert (IMG:style_emoticons/default/drunk.gif)
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| Howard |
Apr 6 2007, 01:06 AM
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#5
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Incontin(g)ent Member Group: Benefactors Posts: 5,785 Joined: 24-July 03 From: Westlake Village, CA Member No.: 943 Region Association: None 
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Kinda like finding the 'G' spot. I just twist it till it sounds right, back off a bit if it detonates. Wish I could help you more.
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| jimkelly |
Apr 6 2007, 06:22 AM
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#6
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Delaware USA Group: Members Posts: 4,969 Joined: 5-August 04 From: Delaware, USA Member No.: 2,460 Region Association: MidAtlantic Region |
finding the G spot on a tranny is hard - but it can be done - don't ask me how I know : )
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| skline |
Apr 6 2007, 07:43 AM
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#7
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Born to Drive Group: Members Posts: 7,910 Joined: 26-December 02 From: Costa Mesa, CA Member No.: 17 Region Association: Southern California |
Well, as I said, TDC is when the piston is at the top of the compression stoke with both valves closed. Good luck.
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| jmmotorsports |
Apr 6 2007, 04:01 PM
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#8
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Member Group: Members Posts: 308 Joined: 15-August 06 From: Kelso,Wa. Member No.: 6,658 Region Association: Pacific Northwest |
Thanks to all that replied. I was not trying to set timing,I use an Electromotive ignition so there is no dizzy. I needed the most accurete way to find TDC to set my crank trigger. The most accurete is the way drive-ability said.
Jerry |
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| andys |
Apr 6 2007, 04:10 PM
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#9
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Advanced Member Group: Members Posts: 2,165 Joined: 21-May 03 From: Valencia, CA Member No.: 721 Region Association: None 
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At the point you're at, the piston stop method, as drive-ability explains, is your best immediate solution. You can actually get pretty darned close. Valve timing is way too vague and it is subject to timing events ground into the cam.
Andys |
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| LvSteveH |
Apr 6 2007, 06:45 PM
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#10
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I put the Poor in Porsche Group: Members Posts: 1,080 Joined: 22-April 03 From: Las Vegas, Nevada Member No.: 600 |
I just ran into the same situation with my V8 914 two weeks ago. I used the piston stop method as mentioned, and marked the harmonic balancer from under the car. I also marked the FW through the hole on the bottom of the trans.
You have to have the car in the air to set timing, but it's very accurate, and easy to see. |
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