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Lt1 piston orientation

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Old Mar 20, 2015 | 10:14 PM
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Default Lt1 piston orientation
Hip deep in cam swap which includes a valve spring upgrade too. Springs are being changed with heads on block. Havin a brain fart here.

I got #1 at tdc. What other pistons are also at the top of thier bores on this position. I know 4 of them are ar the top in this position. Then move the crank 180 degrees and the other 4 are at top.

Is it 1-7-4-6. Then turn crank 180 degrees and 3-5-2-8. Is this right?

You must be wondering why I'm thinking like this. Well, I'll be changing the springs for 4 cylinders in one position, the turning 180 degrees and changing the other 4.
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Old Mar 20, 2015 | 10:23 PM
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The pistons are going to approach TDC in the firing order 1-8-4-3-6-5-7-2. Only one piston is at TDC at a time.
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Old Mar 20, 2015 | 11:23 PM
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Originally Posted by LTxDave
The pistons are going to approach TDC in the firing order 1-8-4-3-6-5-7-2. Only one piston is at TDC at a time.

I'm not asking about firing order but thanks. I'm asking what pistons are at the top of their respective bores at the same time.
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Old Mar 20, 2015 | 11:32 PM
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Damn!!! Crappy overhead spring compressor can't grab dual springs. I shot a retainer into the air. I heard it hit the roof but I can't find it now. Guess I gotta buy a whole new set. And a worthy overhead spring compressor too.
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Old Mar 20, 2015 | 11:38 PM
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# 6 is at TDC same time as #1.
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Old Mar 20, 2015 | 11:41 PM
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No #1 at TDC:
Intake # 1, 2, 5, 7
Exhaust# 1, 3,4, 8

Rotate engine ONE full turn
Intake # 3, 4, 6, 8
Exhaust # 2, 5, 6, 7

Hope this helps

Joel
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Old Mar 21, 2015 | 12:53 AM
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Anybody know of an overhead valve spring compressor that works good with dual springs?

The finger tips on mine don't go in far enough to grab, compress and hold the inner spring.
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Old Mar 21, 2015 | 08:29 AM
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..... I use this valve spring compressor ... it works on triple valve springs .........

http://www.summitracing.com/parts/sum-906784/overview/

..... there are two pistons at TDC at a time , for example ... #1 and #6 ... #8 and #5 ... #4 and #7 ... #3 and #2 ..... when the timing marks are lined up on the cam and crank gears #6 is on its compression stroke ........
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Old Mar 21, 2015 | 08:49 AM
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C409 is correct, I was thinking tdc on compression and forgetting exhaust stroke. I use the same valve spring compressor that he linked from summit, but if the retainer is on top of the spring, that should be compressing both springs not the tool.
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Old Mar 23, 2015 | 08:24 PM
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Originally Posted by C409
..... I use this valve spring compressor ... it works on triple valve springs .........

http://www.summitracing.com/parts/sum-906784/overview/

..... there are two pistons at TDC at a time , for example ... #1 and #6 ... #8 and #5 ... #4 and #7 ... #3 and #2 ..... when the timing marks are lined up on the cam and crank gears #6 is on its compression stroke ........
10-4. I just received shipment of that very spring compressor.

I'm sure this has been seen a bazillion times but here is my progress thus far. My brother has loaned me the LT1 specialty tools for crank hub and optispark.
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Last edited by JD1964; Mar 23, 2015 at 08:30 PM.
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Old Mar 29, 2015 | 06:53 PM
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Got the valve springs all in. Not necessarily an easy job with heads on car.

Soakin up the Lunati rollers now. Pulling the damper, opti and timing cover next.
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Old Mar 29, 2015 | 06:56 PM
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Here's the new attitude.
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Old Mar 31, 2015 | 10:15 PM
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Timing cover, oil pan and opti back on. Dropping the intake on as soon as the sealer beads tack up a bit.
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Old Apr 1, 2015 | 09:40 AM
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That cam is going to make a big difference in it.

Congrats.
Will
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Old Apr 1, 2015 | 12:57 PM
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Originally Posted by rklessdriver
That cam is going to make a big difference in it.

Congrats.
Will
Agreed. But not only the cam. We've also ditched the factory 2.59 rear gear and put in Richmond 3.54.

It's gonna be a different beast.
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