Andrewsvette

I just got my vette on the road today after replacing both head gaskets. I went for a little cruise earlier and it ran fine for a while then it started running rough so I eased back home being careful and watching gauges. I opened the hood and noticed #1 &#3 cylinders plug wires were loose so I put them on and it runs fine BUT! When idling there is a noticeable knock that wasn't there earlier, it sounds like it is coming from the crank shaft pulley area, I have good oil pressure too. I'm afraid this might no be something good... Any help is much appreciated.

Andrew

ladystoy69

because your post dosnt say i am going to have to assume some things...i assume you replaced the head gaskets because they were leaking, but you never say what they were leaking or where(blown between cylinders or leaking coolant and if coolant was it leaking outside the engine or inside) so i guess simple question would be how much coolant was in your oil and i'm assuming you changed it?

Andrewsvette

They were leaking outside the engine no coolant in the oil, I did change the oil

Andrewsvette

Found what is most likely the issue, one bent pushrod and one pushrod laying in the oil valley both on the passenger side... Starting to get depressed with this car I can't catch a break with it

bob guzzy

Everybody makes mistakes, don't worry about it, make the repair and move on, if every mechanic gave up after a mistake there would be none left in the business.

All that happened is when you put it together, you stuck the pushrod in and instead of landing on the lifter it went next to it.

The next time you won't make a mistake like that, it just go's with the busted knuckles and dirty fingernails after a job.

Andrewsvette

I hope that is all that happened, I am pretty embarrassed. Does any one know the factory length of the push rods I need to replace?

desertmike1

It's not the car!! you made a mistake or two along the way, this is how you learn..

Did you keep track of the pushrods when the heads were off,, did you set the Valve lifter pre load correctly? what was done to the heads?

Andrewsvette

Kept exact track of the push rods when the were off top to bottom and each valve, set the preload correctly, nothing was done to the heads except some basic cleaning for reinstall, I'm getting ready to price pushrods lol

96GS#007

As you are finding out, there's a bit more to fixing/rebuilding engines than just spinning a few wrenches. You need to get two things before you do anything else...

- Factory Service Manual. It is the best $100 (used) - $150 (new) you can spend
- You need the following book (click on the pic for a link to Summit):


With the above two items, you can learn everything you need to know about working on these cars.

Andrewsvette

I've been building motors for a while but this is the first lt1 and one of the most modern builds I've done, always learning though lol

96GS#007

In essence, the LT1 is a 60+ year old design, tracing most of its key heritage to the Gen 1 SBC. For instance, setting valve lash on all but the LT4 has been pretty much unchanged forever. Based on your posts, trials, and tribulations, a little extra command media might be helpful....even if you just view it as a refresher.

Andrewsvette

True, I figured the lt1 couldn't be too different from the gen1 sbc I just rebuilt the 350 in my '71 chevelle with no issues. Are the stock pushrods 7.200 in length? 5/16 diameter?

Andrewsvette

Just an update and to say thanks for the help, got some new pushrods in it this morning and with some careful preloading she runs great, thanks for all the help!