On the 'mildly' Cheap SS Monte Carlo chasing a 9.0___

[64nailhead]

I should have mentioned that I had a light ‘tick’ sound on rpm decel as well. It was barely audible, but that noise wasn’t there before I swapped the springs. Of course, I immediately thought I might have boogered up the spring install or a valve during the install.

I contacted BTR and gave the tech guy a full explanation of what I had going on including the parts list. I was advised that the stock pushrod would not handle the BTR dual spring kit and it was a very likely cause if the tick. Regarding the lifter preload the target number should be .090-.100” if using an LS7 style lifter - and the could be the source of the tick as well.

I already had a set of .080 wall hardened pushrods on hand that were .050” over stock length - 7.450” vs stock 7.400”. So I measured lifter preload on 4 cylinders (2 on each side) and confirmed that my setup is between .045-.050” on every lifter I checked. I measured the original pushrods and new pushrods, which revealed enough wear that would make the preload a little less then .045” with the stock pushrods.

I installed the 7.450” hardened pushrods and inspected the heck out of every rocker, valve spring, keeper. Started it up and check - noise immediately gone and the valve train is quieter. Put it on the trans brake a couple of times to make some boost, went through a heat cycle and all seems perfect.

Phew!!

I will say for those of you that ever try to check push rod length on an LS - WOW, what a PITA as compared to a SBC - damn time consuming with nowhere near enough room to adjust the adjustable pushrod on the car. This implies that to adjust the adjustable pushrod and e checking required the rocker to be removed and installed 5-6 times per cylinder - EXTREMELY time consuming.

Don’t be scared to contact a vendor - BTR was great.

 

[81cutlass]

So you went BTR 660's?

I've been rockin the OEM lq4 push rods on my 660/BTR stg 2 blower cam setup for like 15k miles and it's always had a bit of clacky sound to it but I attribute that to piston slap or headers and unknown milage.

 

[64nailhead]

Replacement lifters or originals?

I was told all of the OEM lifters about 2005/6 were ‘LS7’ lifters. The difference is .200” of cup travel vs .120” prior. Pretty much every replacement lifter is now an ‘LS7’ lifter.

Measure your preload.

I should be be able to get some good testing at DW. The motor hit a wall on the dyno with the old springs and pushrods at 22-23psi. I plan to make some hits at that boost level and then turn it up. If it goes faster then the springs and pushrods were the issue.

Time will tell.

 

[81cutlass]

Stock 99 OEM lifters. Didn't realize that was the different to the 'ls7' set. Makes sense!

 

[64nailhead]

Well, I'm working on collecting parts and planning for winter upgrades. For those that missed it, I grenaded the Trusty SS2 Gen 3 4.8 on the last day of Drag Week. It's still on the trailer, and will stay there for another 2-4 weeks until I get room in the garage for it. Then it's off to trying to get faster. I'm hoping to not break the bank, but I'm going to lose the 'on the cheap' logo lol.

I was pulling for breaking my PB and best week's average ET with the 4.8 over the 5.3, but that motor just didn't have it in it. The failure was relatively shocking - no folded rods or exploded pistons, but rather a broken timing chain or crank - I'm leaning towards timing chain, but it will get a full autopsy before I haul it off to the scrap guy.

Regarding Gen 3 LS's, I'm confident that I've busted the myth of the rods are done by 800hp. Back a couple of posts ago I mentioned having it on a wheel dyno and I was done at 23-24psi at 850whp. Then I changed the springs and pushrods and added lifter preload. To check if that issue was resolved I ran my 1st pass of the week at 23 psi and ran a low 9.7 with a high 1.50 60'. Next run I turned it up to 26psi and it dropped .2 to 9.5. That told me that it was making more power past 23-24 psi. After that every pass, with the exception of the last, was 29-32 psi and I worked hard on dropping the 60' . But not with a lot of success, mostly because, I believe, the 4.8 just didn't have the muster of the 5.3. I did manage a mid 9.3 and a 60' 1.39 60', but it was demanding due to having to hit on another 3-4 psi and control the timing retard to not spin. And I'm sure the added 100lbs of the steel 4.8 vs the aluminum 5.3 block didn't help either. Smaller cam was contributing as well. Regardless, the timing chain or crank gave up the ghost about a second after seeing 36psi. Perhaps the boost didn't have anything to do with it and it was just time for it break. I can't be sure. But this thing lived all week between 7700-8100 rpm's. And when it was in the car previously it ran in that range for over a year. I'm quite confident that I was over 1000whp and the rods and pistons are still in tact. Of course the timing was a little safer as well - about 1.5 degrees less timing when it was over 30psi from where I was with the 5.3.

Either way - Trusty 4.8 RIP.


I've got more turbo on order, a little bigger ceramic ball bearing unit that has been touted to be 1300hp capable. And I should've mentioned, my VS 85/102 is done. When things went south it was at 34 psi, 6900, 70+ psi of oil pressure, and by 6400 rpm's I had 1 psi of oil pressure. The turbo spool down did not fair well. It still spins, but it too loose to put any faith in and the compressor wheel sits on the housing. Game, set, match on that poor thing lol.

I'm going to run the Summit forged piston/rod deal again in the 5.3 and I'm yet decide to buy a set of heads or have one of my sets of 243's ported. Either way, it will have a head that should be worth another 20-45HP naturally aspirated; which will multiply as the boost comes in.

For safety stuff, I'm trying to determine my best route for more brake in a 15" wheel, and I'm getting a chute setup as well. I'm supposed to have one at 150mph, and I'm going to get past that. And at 150 now it's it's way too nerve racking getting it to stop unless I have 2500-3000ft run down past the stripe. 2 of the DW tracks were 2000' and less and holy sheetz - I don't care for that.

I'll keep the updates coming as they come along.

 

[melloelky]

*still living vicarisly through this thread/car*

 

[64nailhead]

*still living vicarisly through this thread/car*

🙂

I should've mentioned that I'm considering a rack and pinion swap too for a couple of reasons - weight savings and engine pan. But I need to do a lot more research on what does and doesn't work with the swap.

 

[melloelky]

godspeed..

 

[64nailhead]

Starting point of putting the car on a diet.




Iron 4.8, no coolant and 4 gallons of e85.

Hopefully 200+ lighter by spring and at least 150 off the front.

 

[Supercharged111]

Starting point of putting the car on a diet.

View attachment 231083


Iron 4.8, no coolant and 4 gallons of e85.

Hopefully 200+ lighter by spring and at least 150 off the front.

Are those scales yours Mr. Fancypants?