Congrats on getting it running! Always a nice feeling.

To me, it looks almost as if the pushrod length was determined with the lifter not quite on the base circle. I listened to your car run in the outside the hood video, and that sounds like lash. Then your third video sort of confirms it.

You could take an educated guess this way... slide a feeler under the rocker tip and figure out how much lash you got. Remember that lash won't exactly translate, so divid your lash by 1.7 to get the preload equivalent. To make the math easy, say you have 0.017" lash, then a 0.010" longer pushrod will get you to zero. Then another .050 for the actual lifter preload, and you'll be at 7.060".

At that, even if you ran 7.075", your preload would only be 0.065, but then you gain .010 from thermal expansion, so you're back to 0.055" warm preload, and likely very happy.

 

Thanks it is for sure! thanks makes a lot of sense actually, i will use that to confirm what I'm getting with my readings now. so far looking like about 10-10.25 turns out so 7.36" push rod with .060 preload correct? so kinda don't know if i should go with 7.35 or 7.375.

 

Well went and checked with feeler gauge. It was .024 that got me to zero lash so that would put me at 7.324 plus .060 for preload and end up with a 7.384. just seems to big but i know every engine is different. Kinda makes me lean towards a 7.375 but I'm gonna check cyl 3 in a bit

 

well ****, after checking my exhaust side with feeler gauge its a .014 so after adding .060 preload I'm at 7.374. Now getting zero lash, it was a lil more that 10.25 turns out and less than 10.5 so given that and .060 preload looks like ill be pretty solid with a 7.375 push rod.

 

Yup 7.375. That .024, divide by 1.7 due to ratio. You're like .014, add 050, call it 7.375 and roll

 

awesome, thanks for all the help! 1 thing i don't understand really is losing pre load at operating temp. I would think metal expansion you would gain preload?

 

Aluminum grows faster than steel. Block and heads are aluminum, pushrods are steel. The block and heads grow more than the pr

 

Don't want to lose dis. Subscribed.

 

Don't count turns. Tape the threads on the checker so it doesn't move and then measure it with a digital caliper. Best $29 you can spend...

 

makes sense darth, Thanks again for all the help. I might try and find a caliper in town today just to triple check my measurements, thanks!

 

Harbor Freight has a good one. I use it.

 

ok cool. don't have any of those real close, sure ill find one though.

 

Here is my push rod length checker, Cut a factory one, thread the hole in the middle,
cut the head off of a screw the size you threaded hole with, some nuts to lock it with,
I extended some wire out of the wire welder, tacked it on for traction and hold it still, it
is tight on these heads where you need to be when spinning up to zero lash. Zero dollars.
And strong enough to spin cam around, all torqued down. Turn nut to lock it in place,
remove rocker arm, measure push rod, add preload, Done

 

thats awesome, thanks for the idea!

 

Any hardware store will have one.
Fleet Farms have them

 

sweet, never heard of fleet farms lol

 

Lol, I was wondering about that, than was like, what the hell..... maybe they are every where.

Fleet Farm must be a Minnesota/Wisconsin thing.

 

Lol when I worked in MN for a bit, I was like wtf is fleet farm.. I'm from Michigan and never heard of one.. any home depot, lowes, menards, etc should have one..

I started mine yesterday and it sounds awesome! Valve train is WAY quieter than expected.. no noise on initial start up at all due to priming the oil pump. The tuner noticed it was very snappy compared to his set up that doesn't have the .040 gaskets and has different heads. I'll try to get a video today and post it!

 

Well congrats glad its good! I agree the car is extremely responsive. Cant wait to hear and see with the right push rods. Post it up!

 

https://ls1tech.com/forums/generatio...-cometics.html

Here is the link to my videos and thread. I bet it sounds pretty familiar to you since our builds are pretty close!