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Pushrod length issue

 
Old 05-15-2019, 10:11 PM
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Default Pushrod length issue

Had everything together, ordered 7.350 pushrods from TSP that came with my head cam package. Went to fire up and nothing... Crank and spark but no running. Soo...... I double checked everything (damn cam was upside down (dot was opposite of crank at TDC)) and double checked my pushrod length and now I'm getting some ridiculous low number (31.25 turns to 6.125... = 7.21875). I know the preload on ls7 lifters is .080 to be safe, but I don't feel confident or comfortable in that number. Managed to lose 1 pushrod in the process too . Anybody else running 7.3 or am I not measuring it correct?
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Old 05-15-2019, 10:18 PM
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With No.1 at TDC the dot on the crank gear should be up at 12:00 and the cam gear dot down at 6:00 so if both are up that's incorrect.

I'm confused here. Did the head cam package come with predetermined length pushrods or are you having to measure for pushrod length?

If you now have the cam installed correctly then go ahead and double check your measurements for PR length.
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Old 05-15-2019, 10:24 PM
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When measuring pushrod length you can either use the EOIC method or put the cylinder your checking at TDC on the compression stroke. I like the EOIC method personally and I usually measure PR length on 2-3 cylinders to make sure I'm getting consistent numbers.
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Old 05-15-2019, 10:25 PM
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When you order the package, you're supposed to select pushrod length. Couldn't measure cause I never had the heads installed or cam lol. The crank is up, cam dot down... I even stuck a lizard cam in the spark plug hole for the 1st cylinder. Measuring the intake side I have a rocker halfway down bolted in to keep the pedestal from moving/shifting.

I'm just tightening the bolt till it bottoms out, not torquing it and I found a spot where it doesn't tap but has slight side to side movement, nothing up and down
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Old 05-15-2019, 10:32 PM
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Make sure your on the base circle of the cam when measuring for PR length. Are you familiar with the EOIC method?
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Old 05-15-2019, 10:36 PM
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Originally Posted by 01CamaroSSTx View Post
Make sure your on the base circle of the cam when measuring for PR length. Are you familiar with the EOIC method?
Not the EOIC method... I checked that the piston is at it's furthest point up before measuring on the intake... Can't imagine TSP would've milled off that much, didn't ask/order for it
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Old 05-15-2019, 10:37 PM
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Is the engine in the car or on an engine stand?
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Old 05-15-2019, 10:37 PM
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Originally Posted by 01CamaroSSTx View Post
Is the engine in the car or on an engine stand?
In the car lol...
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Old 05-15-2019, 10:38 PM
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Are the spark plugs still in?
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Old 05-15-2019, 10:39 PM
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All but the first cylinder
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Old 05-15-2019, 10:52 PM
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Removing the spark plugs makes turning the engine over by hand much easier because you not building compression but I understand if you don't want to go through removing them all. With the valve cover off go to the No. 1 cylinder and with a rachet on the harmonic balacer bolt turn the engine over clockwise while watching the intake and exhaust rocker arm events. It's easy to tell the difference in which rocker arm because the exhaust rocker arm is in line with the exhaust primary. EOIC- exhaust opening and intake closing.

Turn the engine over by hand until you start to see the exhaust rocker arm begin to open the valve and then stop. The intake rocker arm for that cylinder is now on the base of the cam for that lobe and can be measured for PR length.

Turn the engine over by hand again while watching the intake rocker begin opening and then beginning to close and stop. The exhaust rocker arm for that cylinder is now on the base of the cam for the lobe and can now be measured for PR length.

If your able to determine that you are at TDC and both valves are closed for any given cylinder then by all means you can measure PR length on the intake and exhaust for that cylinder.
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Old 05-15-2019, 11:06 PM
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Since you don't have any PR's in the engine you need to get the No. 1 at TDC and measure for PR length if your cam is now installed correctly.
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Old 05-15-2019, 11:30 PM
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I'm using the trick flow specialties one, supposed to be .035 every turn.. and have the can installed tdc 6 to 12

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Old 05-15-2019, 11:39 PM
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I've never used one of those so it's 6.125 when fully closed and .035 per turn?

Yeah I'd just just install the PR checker onto the lifter and make sure it's short enough so that when you bottom out your rocker bolt you still have play in the rocker and then start adjusting the PR tool out until you take up all the slack out of the rocker arm. No ticking but a little side movement is okay and that should be zero lash. I like to use a dial gauge to measure the length as a check to counting the turns but whatever that is plus the recommended preload for the lifter and that should be your PR length.
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Old 05-15-2019, 11:41 PM
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I can see you have it dot to dot and the dowel pin hole for the cam is in the right location.
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Old 05-16-2019, 12:54 AM
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This **** makes me nervous. I've yet to find someone that's running that short of a pushrod with the same combo. I didn't get my deck milled, idk about the heads, I just bought them used and using most gaskets... I always thought that the base circle on the228 cam was smaller anyways, requiring a longer pushrod. I'm gonna try the 7.300 pushrod from summit if they have it... Idk what to do about my tsp pushrods, already bought then and I'm missing one. I remember dropping it in the engine bay and not finding it underneath, hoping the neighbors dog didn't find it lol
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Old 05-16-2019, 12:21 PM
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I could be mistaken, but I believe the cam dot at 6 and the crank at 12 is TDC firing on cylinder #6, not cylinder #1. So if you measure cylinder #1 you may get some skewed values. Also, not sure if you are following the instructions for that adjustable pushrod, but they aren't correct for an LS1. Don't rotate the motor when using. Also, be sure you aren't depressing the lifter at all if they are new lifters, the pushrod cup can move easily if new.

If you rotate the motor so you see the #1 intake valve closing by placing a pushrod in that lifter, then bring the #1 piston to TDC so your dots are aligned you will know cylinder #1 is at TDC of the firing stroke.

Hope this helps.
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Old 05-16-2019, 12:37 PM
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Originally Posted by vettenuts View Post
I could be mistaken, but I believe the cam dot at 6 and the crank at 12 is TDC firing on cylinder #6, not cylinder #1. So if you measure cylinder #1 you may get some skewed values. Also, not sure if you are following the instructions for that adjustable pushrod, but they aren't correct for an LS1. Don't rotate the motor when using. Also, be sure you aren't depressing the lifter at all if they are new lifters, the pushrod cup can move easily if new.

If you rotate the motor so you see the #1 intake valve closing by placing a pushrod in that lifter, then bring the #1 piston to TDC so your dots are aligned you will know cylinder #1 is at TDC of the firing stroke.

Hope this helps.
Thanks for the advice on that.. gonna double check the valves opening/closing sequences and make sure it's accurate.i stuck a camera in the spark plug hole, I brought the piston up to it's highest point, figured that was the spot but gonna try again lol
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Old 05-16-2019, 01:53 PM
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Think your on to something about the correct position... Found a video of a guy doing a boosted c6, he found his length with the crank and cam at 12 o clock position. Tried it myself and ended up with a 7.375 will give me a preload of .095, Soo... Either need to see if Texas speed can send me 1 pushrod or buy a new set with a shorter length of 7.365 or 7.36
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Old 05-16-2019, 03:09 PM
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31.25 turns x .035 + 6.125 + .080 preload= 7.30

When No.1 is at TDC the keyway on the crankshaft should be around the 2:00 position if I'm not mistaken? I've just finished up with ring filing and piston/rod assembly and will be going back through this. If the cam is installed correctly the No.1 piston will be at TDC, the crank gear dot will be up at 12:00 and the cam gear dot should be at 6:00 which is referred to as dot to dot and the dowl pin on the camshaft should be in the say 2:00 position as shown in your previous pics.

I'm about to start short block assembly and hopefully this weekend get the camshaft degree'd in but if its installed correctly use the EOIC method and insert a pushrod onto a lifter and place your finger on the tip and turn over the crank until you feel it move. Check and double check your measurements and do this until you feel comfortable that your measuring correctly. If you keep coming up with a consistent number then most likely your on to something.
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