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Heads are off - TDC / Base Circle for measuring Push Rods
I got my heads back today - FINALLY! Gonna clean everything up and install them. It will be easy to put #1 at TDC. How can I tell if it is compression or exhaust stroke? Or will that not matter.
I want to measure for the correct PR's while I re-install the heads. Can someone share a slick way? I think there is a method to have #1 at TDC, Install 'some' of the PR's, Spin the engine (90*?), install some more, rinse and repeat till all are torqued. I do NOT want to tighten them all at once - with full spring pressure on some - others have done that with no problems, I don't like the idea.
I have the adjustable PR and I think if #1 is TDC then it is also on the base circle of the cam - correct? Are there other Cylinders on the base circle as well?
Am I confusing myself enough? or is this a good thing - having the heads off at the start.
Thanks for any insight & help
I got my heads back today - FINALLY! Gonna clean everything up and install them. It will be easy to put #1 at TDC. How can I tell if it is compression or exhaust stroke? Or will that not matter.
I want to measure for the correct PR's while I re-install the heads. Can someone share a slick way? I think there is a method to have #1 at TDC, Install 'some' of the PR's, Spin the engine (90*?), install some more, rinse and repeat till all are torqued. I do NOT want to tighten them all at once - with full spring pressure on some - others have done that with no problems, I don't like the idea.
I have the adjustable PR and I think if #1 is TDC then it is also on the base circle of the cam - correct? Are there other Cylinders on the base circle as well?
Am I confusing myself enough? or is this a good thing - having the heads off at the start.
Thanks for any insight & help
Yes u will b on the base of cam both valve closed. Stick toilet paper or whatever u want. Not in the chamber just sung enough to hold so when you turn the engine and it blows out u will be coming to TDC. JMO easy
Thanks for that. I've seen videos on PR length but not that one. Helpful.
So... With my heads off I can spin the engine and see what is at TDC every 90, 180, and so on. I remember seeing a cheat sheet about tightening rockers so there was no additional pressure on them. It was in steps. Start with #1 and #?, Spin it and do 2 then spin and do another 2 etc. It will be easy to see headless. I'll take notes.
Just to be sure, If any piston is at TDC the lifters WILL be on the Base Circle - Right?
Thanks again
Thanks for that. I've seen videos on PR length but not that one. Helpful.
So... With my heads off I can spin the engine and see what is at TDC every 90, 180, and so on. I remember seeing a cheat sheet about tightening rockers so there was no additional pressure on them. It was in steps. Start with #1 and #?, Spin it and do 2 then spin and do another 2 etc. It will be easy to see headless. I'll take notes.
Just to be sure, If any piston is at TDC the lifters WILL be on the Base Circle - Right?
Thanks again
Thanks 4FL - It was similar now that I think about it. I don't recall the 360 spin but it WAS a combination of IN & EX in the sequence.
Is there a was to tell if my TDC #1 is on the Compression or Exhaust stroke without removing the front cover and looking for Dot-to-Dot? Or doesn't it matter?
Will this work.... Put #1 at TDC and look to see what else is at TDC. Note it. Spin ??* it till another pair is there - note that. Continue till I have them all noted. Put #1 back at TDC and mark the Balancer with a paint dot. Put heads on, measure PR's at #1 & #?. Get correct PR's (I have 7.4's and 7.45's) and finish up.
Make sense?
Thanks again
I found it - Was on LS1 HowTo Dot Com.
I do know that some people here question some of their work for accuracy / safety. Here's what they say. This assumes the front cover is off and the gears are Dot-to-Dot. But as long as the piston is TDC it should be base circle regardless of which of the 4 strokes it is on - Right?
I assume this would also work to measure PR length - which is why I asked in the first place... If I measure #1 & #6 IN and EX I should have a good idea of the correct length for both (Hopefully they are the same)
This method is a bit more elegant. Rotate your motor over by hand until your cam gear and crank gear are dot to dot like you set them up as earlier. At this position, piston 1 and 6 should be at top dead center. You can change the 4 springs on these 2 cylinders now using the instructions below. After you change those 4, then, rotate the crankshaft a full 90 degrees, and the cam gear dot will turn 45 degrees, as if it is pointing to 7:30 if it were a clock. Now piston 8 and 5 are at the top and can be changed. Rotate another 90 degrees on the crank and your cam gear dot will now be at 9 o'clock. Piston 7 and 4 can now have their springs changed. And FINALLY, rotate the crank another 90 degrees and the cam gear dot will be at 10:30. You can now change your remaining four springs on piston 3 and 2.
I found it - Was on LS1 HowTo Dot Com.
I do know that some people here question some of their work for accuracy / safety. Here's what they say. This assumes the front cover is off and the gears are Dot-to-Dot. But as long as the piston is TDC it should be base circle regardless of which of the 4 strokes it is on - Right?
I assume this would also work to measure PR length - which is why I asked in the first place... If I measure #1 & #6 IN and EX I should have a good idea of the correct length for both (Hopefully they are the same)
This method is a bit more elegant. Rotate your motor over by hand until your cam gear and crank gear are dot to dot like you set them up as earlier. At this position, piston 1 and 6 should be at top dead center. You can change the 4 springs on these 2 cylinders now using the instructions below. After you change those 4, then, rotate the crankshaft a full 90 degrees, and the cam gear dot will turn 45 degrees, as if it is pointing to 7:30 if it were a clock. Now piston 8 and 5 are at the top and can be changed. Rotate another 90 degrees on the crank and your cam gear dot will now be at 9 o'clock. Piston 7 and 4 can now have their springs changed. And FINALLY, rotate the crank another 90 degrees and the cam gear dot will be at 10:30. You can now change your remaining four springs on piston 3 and 2.
But...How the HELL do I get the engine to turn without using the Starter Motor? I've tried Everything I have to get a wrench on the Balancer Bolt (ARP - 12 point). I'm using an offset DogBone and it just won't go on. Tried both 15/16 and 1 - 1/16 - just no room behind the rack. Also tried locking one axle with vice grips, putting it in 1st and turning a tire - it slips. Also tried wrapping the belt around the Balancer and yanking - won't budge.
I'm reluctant to hook up the starter. I'd have to pull a bunch of fuses (Fuel for sure - there are no coils or injectors connected).
Story of my life. A simple afternoon project turns into a 'Thing'
Thanks again for all the help
The 24mm side of this reaches the crank bolt easily from the passenger side. I just went out to the garage and was able to turn the engine with the plugs in and everything hooked up.
I wouldn’t try to loosen the bolt with this wrench, but fine for cranking it over.
We have a local 'Surplus City' that sells Tekton stuff. I was using a 15/16 - 1" similar offset wrench. I've read that the ARP can be either 15/16 OR 1-1/16. I guess I came up short. again
I'll see what I can get locally - If a No-Go then Amazon it is.
Thanks
We have a local 'Surplus City' that sells Tekton stuff. I was using a 15/16 - 1" similar offset wrench. I've read that the ARP can be either 15/16 OR 1-1/16. I guess I came up short. again
I'll see what I can get locally - If a No-Go then Amazon it is.
Thanks
There are different angle offsets and depth. You need the more gentle curve offset angle, if that helps. The diff between the 15/16 and 24mm is very little, so it probably comes down to the bolt/brand or individual wrench, etc. I have definitely needed SAE size wrenches on some bolts on my car, where the metric tool felt sloppy by comparison.
We have a local 'Surplus City' that sells Tekton stuff. I was using a 15/16 - 1" similar offset wrench. I've read that the ARP can be either 15/16 OR 1-1/16. I guess I came up short. again
I'll see what I can get locally - If a No-Go then Amazon it is.
Thanks
I was using this wrench on a stock bolt!
The ARP is 1 1/16” … or 27mm is the closest. So the other end of this may still work. You could double check with a short 27mm socket. The difference is 0.12 mm
Last edited by vette4fl; Jun 10, 2023 at 03:41 PM.
Vette4FL - That wrench is the ANSWER! Works like a champ. Spins easily. I made a pointer out of TIG rod and marked verey 90* on the balancer with a paint dot.
I'll get busy - Father's day will Monkey Wrench it a little but... I have a plan
You da MAN!!
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Heads are off - TDC / Base Circle for measuring Push Rods
