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Discussion Starter #1
Yes Yes I know.....I should have checked them before full ass'y. Turns out the 7.425" BTR pushrods are way too long. I am posting this so if you are in the middle of a build DO NOT SKIP THIS STEP!!
Took Driverside Valvecover off and checked No. 1 Intake and Exhaust. Adjustable Crane tells me the Intake zero lash is 7.325 and the exhaust was 7.300.
Gunna go with some 7.375's...Thoughts??
BTW she is a bit clattery almost like they are too short...Just hoping I haven't damaged anything...
 

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F1rehawk
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I have spoken with Cory @BlueLinePerformance and apparently it depends on the lifters you are using as well. I ordered the Johnson Lifters and was told the 7.425" BTR pushrods would be too long.

"I was looking over your order. You made a great choice on the Johnson lifters. Before I process it though I wanted to confirm the pushrod length with you. Generally Johnson lifters take about half the preload of the Ls7. Are you planning on milling your heads or keeping them stock? If I know that information I can better help with pushrod length as I am 99% sure the 7.425’s are going to be too long for you."

Hope that helps a bit.
 

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I had a similar experience. Luckily I had 7.425 and 7.400 on hand when assembling my engine the first time, and ended up using the 7.400, but 7.375 MAY have been a little closer to spec. LS7 lifters have a preload range of .050" to .100", which is pretty wide. In theory, you want to be right in the middle. I was a little on the tight side with the 7.400. The 7.400's lived happily with BTR Stage 2 cam and LS7 lifters for 7k miles.

Given your measurements, I'd say 7.400 is right, and would put you in the middle of the range. A bit more info would help too... what cam? did you mill heads? etc

To add onto GTRenegade... I'm also switching to to Johnson 2110 lifters. I ended up calling Johnson and talking to one of their tech guys for a bit. They spec 0.035" plus/minus 0.010" for the 2110 lifters, and if you're running an aluminum block, you need to be on the tighter side to account for thermal expansion.
 

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Discussion Starter #4
Thx for the responses. I used the BTR stage 2 LS3 cam. No milling of heads. No decking of Aluminum block. My machinist recommends .030 to .040 preload. Going to run the 7.375. Will post results. Have got some clatter wit the existing setup. Best as I can figure I have almost collapsed the usable real estate in side the lifter and it is unable to “adjust” with the oil pressure. I am hoping I haven’t damaged anything...:(
 

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7.375 with LS7 lifters or are you running johnson/moroso linkbars? Everywhere I've looked that set up wants 7.4 so odd...(Thats what I got, havent started the car to find out.)

For what I gather the valve train noise (assuming nothing broke on you.) would usually be from things being too short rather than too long. Too long would just mean loss of compression and greater wear on springs. Honestly i think your rods are too short.
 

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Just some added info. I was running 7.400 with LS7 lifters. Swapped to Johnson 2110's, and my machinist still spec'd 7.400.

The Johnson's only call for .035" of preload, but they're 0.45" taller (or so the internet says), so end result is similar to running LS7 lifters.
 

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Just some added info. I was running 7.400 with LS7 lifters. Swapped to Johnson 2110's, and my machinist still spec'd 7.400.

The Johnson's only call for .035" of preload, but they're 0.45" taller (or so the internet says), so end result is similar to running LS7 lifters.
Interesting, I was actually gonna go with a set, but by that point money was tight and I went with LS7. (I figured next time I get into the motor will be to either stroke or swap.) Since I don't really race anyway, just normal speeding.

It's a bit complex but I know cam also plays a big role in it. I might be wrong on this, but I think aggressive cams you have to run short where with milder cams you can run longer.
 

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It's a bit complex but I know cam also plays a big role in it. I might be wrong on this, but I think aggressive cams you have to run short where with milder cams you can run longer.
It's actually a bit of the reverse. Often a more aggressive cam will have a small base circle in order to achieve the desired characteristics. Therefore you need a longer pushrod to make up for it.

But yeah, in the end... measure, measure, measure. Every setup is different.
 

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Discussion Starter #9
So I put the shorter rods in and I still have a couple of tickets....now wondering if I have a couple of screwy lifters. They all took preload of about a turn. Really wish I had taken the time to do this on the stand.
 

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What oil are you running? I switched from Synthetic 5W-30 to Synthetic 10W-30 and it got rid of most of the ticking. Or add 1/2 a bottle of STP oil treatment. That will cure the Ticking. It also fixed the low oil pressure at idle too ,and pulls better.
 
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