Some day go 5/8. 50 years from now they will find my car in a junk yard and the studs will be be perfect lol.

 

If I ever seriously upgrade the power in this thing, I'll definitely beef up the studs. The ARPs seem pretty solid for what I'm doing, though.

 

[QUOTE=LS1Formulation;20556445]After I got the block back and fully cleaned, I assembled it with a stock polished crank and Summit Pro LS .030 over domed pistons/QUOTE]

I didn't know you could bore an aluminum block to .030 over. Were these forged pistons and what wall clearances did you end up with?

Great build BTW.

 

[QUOTE=LSswap;20607145]Thanks! This an LH6 engine, so the block has really thick bore liners. You can bore them .125 over to LS1 size . I chose to only go .030 for strength and future rebuildability. I have Summit ProLS domed forgings in it. As for piston to cylinder wall clearance, Steve Morris machined my block and he set that up. I'd have to look at my paperwork to know for sure.

 

Did not know that about LH6. Always open to learn. Thanks!

 

Did you end up running the stock rockers with those AFR heads? I had been looking into those vs cleaning up some 243 heads but saw they recommended the use of roller rockers because of the valve guides.

 

I did end up running stock rockers, but I am planning to freshen the engine up at some point and will either switch to BTR canted valve heads or have powdered metal guides installed in these.

 

Haven't updated this thread in a few months, so I figured I'd add a bit to it. Every time I think about doing an upgrade, either something breaks or wears out and has to be put on the back burner. So no Hitmaster for me this year. Mostly due to my unfortunate miscalculation of running M/T ET Street R's on the street. $900 a pair, and 900 miles until cords were showing. I figured they'd last me until next spring, boy was I wrong. So I replaced them with Nitto 555 R2s and I'm much happier with them. I'll eventually get a dedicated pair of track wheels/tires and stick to the Nittos for street driving.

Another miscalculation I had was spinning my alternator too fast. This engine pulls like crazy up top, and I've hit 8000 RPM more than a few times, especially on the 1-2 shift. I originally just slapped on a 165 amp Powermaster alternator with the stock 2" pulley. Wrong move, as that got the alternator spinning close to 30K RPM. I went to a 3" pulley after that, but recently I found that it was dropping voltage over 5000 RPM. Ended up sending it in to Powermaster and they found that the voltage regulator was fried, likely due to the overspinning. Had them replace that and install a 3.5" pulley, along with a flat back plastic cover, as I had to modify the vented F-Body cover to fit up top on the passenger side. They have a pretty nice repair program, no labor and all parts are at cost. I just got it back yesterday. Prior to sending it out, I fixed an issue with the Huronspeed alternator brackets. The brackets are pretty beefy and work well, but there's no triangulation which allows the alternator to flex downward under tension. I remedied that with an adjustment rod and rod ends. Had to add a couple spacers to get enough angle to make it work. After install, I had zero flex from the alternator:




Another failure, but this time with a simple fix, was the coolant overflow/battery hold down snapped off like they tend to do. Hard launches with a heavy battery makes it inevitable. I didn't want to replace the coolant overflow without beefing up the battery mount somehow, and stumbled upon a perfect fix. My work had a huge amount of extremely strong brackets that were leftover from a long completed job and were just going to send them to be recycled. I looked at one and realized it would be perfect to chop up to make a holddown bracket for my battery. The steel is thin, but it's so strong it's nearly impossible to bend by hand. I had to drill a hole in it, and it was impossible to drill through it with a hand drill. I ended up using a die grinder with a carbide bit to put a hole in it. Lucky for me, the headlight mounting bracket had a bolt in line with the center of the battery, so I just used that. Looks pretty clean, and it's so strong I cannot flex the battery backwards, even with the original battery hold down broken:


Aside from that,I'm still working on my tune and figuring things out. My alternator problem was causing a fueling issue, as the voltage drop made the pump stop working as well. I have a Kenne Bell Boost-A-Pump on my secondary fuel pump, but when my voltage was dropping under 12V at high RPM, the primary fuel pump wasn't pulling it's weight. I am likely going to have to upgrade to twin 525 Hellcat pumps over the winter, as these Racetronix 340's seem to be tapped out and I haven't even started pushing the car yet. I have an issue with boost control as well, as it spikes on every gear change before settling flat. I'm using Holley's Boost VS. Dome control strategy, which seems like it should be able to tame the spikes down, but I'm still learning how it functions and have not settled on the correct settings to make it work right.

 

I did run a couple of PBs with the car about 2 weeks ago, even with the issues I was having with fueling. I did forget to mention in my last post that I'd went to 2 different tracks a month ago over 2 days, and each time I was having extreme fuel pressure drops that were shutting my car off ( so thankful for Holley's safeties! ). I thought it was just the voltage problem, but unknown to me at the time, I had a serious fuel leak coming from the # 8 injector O-ring. I had blown a collector gasket and got that fixed, and was idling the car on jackstands to get some heat in the exhaust so I could retorque the studs. I looked under the car to check for something and saw a huge puddle of fuel and fuel running down the bellhousing. I shut it off quickly and finally saw the fuel spraying out of the fuel rail. I can't believe I hadn't noticed it before. If you're having fueling problems, check for leaks! I am damn lucky I didn't burn my car to a crisp.


After that was addressed, I was able to take the car back to the track and make some passes. Prior to that, we had an event here in Grand Rapids, MI called Metro Cruise, which is like a smaller version of the Woodward dream cruise. They have a dyno available and charge $50 for 3 runs so I figured I'd slap the Firebird up there to see what it could do. I didn't want to push it, so I only ran 15PSI of dome which equated to 13.5 PSI of boost, but it still made 643 RWHP at that level, which is pretty good. I'm pretty sure it's over 700 at 18PSI of boost, which is what I was running at the track that night.

 

Get yourself a JS Alternators unit, they're good from idle to 9,000 rpm.
I've spun mine as high as 7,500+ rpm and voltage is steady.
I opted to go with their truck case just for more output at idle with all the accessories I use but you can get them in the smaller F-body case too.

 

I've taken mine to 9500+RPM with a 10% UD balancer and a 3" pulley on the alternator. JS makes some solid stuff.

 

If I have to fix this one again, I'll probably do that, but I've already got it back and it's good to go. I added a 3.5" pulley so there's no way I'll overspin it. It loses some output at idle, but I don't really have a lot of crap running at idle so I'm not concerned.

 

If you start noticing your battery not being as strong, you'll know why.
Mine worked okay but it seemed like with all the low-speed cruising I would do, the alternator simply wasn't putting out enough power down low to keep the battery topped off over time.

 

Not to hijack, but I wonder if that's what I'm running into with my car. I've had my car together for several years, used to spin to 7200rpm with stock alternator pulley, and I've been turning the rpm down every year(maturing, I'm only 22yo), now shifting around 6400. Last fall I started dropping voltage above 5200rpm(probably hurt from overspinning), added a larger pulley and got the voltage back but my car just doesn't seem like it wants to crank up after sitting for a couple days. I still read ok voltage at idle but suspect an issue. Old crusty 105a small case truck alternator, will likely replace with the large case D44 truck alt, I think they are 145A.

Back to the topic, your car is moving out nicely man. Freight trains up top, traps really well. Cant wait to see what you'll do with the Hitmaster.
Glad you caught that fuel leak, would have been terrible shame if the car burned down with all the care and work you've put in. Do you have a fire extinguisher in the car? My TA has one, the C10 needs one.....

 

Your alternator issue is exactly what my car was doing, the battery was weak from repeatedly not being fully brought back up as well.
My previous alternator was a Powermaster, had to pulley it down to work at 7K but then low speed voltage output suffered.
Went to a 320amp JS truck case unit and never looked back, you most likely don't need 320 amps, and they do make a 250 amp iirc in the smaller F-Body case which would be plenty.
I see 14.1-14.5 at idle and 13.5 at 7,500 rpm because I think the F-Body ECU is lowering the sense lead voltage to reduce drag or something.

 

So, with the new pulley on, I am seeing 13.1v at idle but as soon as I am above idle, it's putting out 14.5v. While I'm doing low speed cruising, it never drops below 14.4. I hardly ever sit at idle, except maybe at a stoplight. Once I swap my rear gears out, I am likely going to return to the 3" pulley because I doubt I'll have issues with overspinning the alternator after. I am consistently seeing 8000 RPM on the 1-2 shift because of how fast it revs, I apparently cannot react quickly enough to my 7K shift light to get a gear change made, lol.

@wlink14 , it's pretty likely you fried your regulator. That's what happened to mine. I took it in to be tested locally and it tested out fine, but they don't spin them very high so at low speed it was putting out 14.4v. I returned it to Powermaster and under their testing they found the regulator bad. I'd just upgrade yours like you'd said but add the bigger pulley. 3" seems to be the sweet spot for sub 7K operation.

As for my car, I'm really trying to perfect the launch without resorting to the Hitmaster just yet, and I'm getting better. A 1.67 60' time on 17" radials actually isn't that bad when you think about it, and I'm pretty amazed that it was on Nittos. I may still get a Hitmaster for consistency purposes and because I like adding tech to my car. I'm going to have to redo my fuel pumps over the winter before I turn it up, though. Even with the alternator fixed, I'm dropping fuel pressure under high demand situations and it makes it impossible to tune at high RPM/high power. I've left the timing soft up top as a safety, so in those videos at the track, I'm only running about 13-14 degrees. I also have it really fat, so CL comp is generally pulling 6-10% out above 10PSI just so I don't run into trouble. Once I can get consistent fuel delivery, I'll sneak up on max power.

 

The powermasters have a voltage drop-out issues below a certain RPM. I f-ed with this for probably 6 months before getting fed up and just instrumenting the car up to dive in. The punchline is that you have to be particular about the larger pulley size and too big, you are just driving around on the battery. Min speed (at the alternator) I found needed to be 2,500 rpm. The downside of this is that it implies the operating window of the powermaster is not great - when selecting a pulley, either pick low-rpm voltage drop out problems or overspinning. I chose overspinning mine a smidge.

https://ls1tech.com/forums/wiring-st...tage-drop.html

 

I've been thinking about the alternators high RPM issues as well. I noticed that the voltage was erratic at the top of the track in my case as well. I theorize that it might be caused by the slip rings not making good contact at certain RPMs because of vibrations and harmonics. I would think that a well balanced rotor and well machined slip rings will eliminate this problem. Also a stronger set of brush springs may help somewhat.

Also, maybe rubber insulating alternator mounts to reduce vibrations from the engine?

I used to balance the armatures and remachine the commutator on my slot car motors back in the day because they spun up to ridiculous RPMs. I built a sensitive dynamic balancer that worked great.

I haven't tried re balancing the rotor yet, but I did double up on the brush springs. Have not had a chance to bring it back to the track to test.

 

The JS alternator actually comes with an overdrive pulley from the manufacturer and its pretty small, looks smaller than the factory pulley tbh.
JS states in bog bold letters not to remove it and install a larger pulley or it will void the warranty lol.
They must build them right because mine has seen 7,500+ rpm several times and never misses a beat, can't imagine what that guy is spinning with that little pulley.

 

I gotta vent for a minute, and I'm sure a lot of people will empathize with my frustration. Lately, it seems like every single time I fix anything on my car, something else goes wrong. I got my alternator issue fixed and took it to the track, and somehow my driver's side fuel rail mount bolt came loose and let the injector spit out an O-ring. This was in the middle of what would have been my first 10 second pass, as the incrementals to the 1/8 mile were over a tenth quicker than my 11.09 pass. I am lucky I am running E85, because my entire engine bay got doused with fuel. And to make matters worse, the fuel was spraying out in a way that in the low light of the track, it looked like I had split an AN fitting. So I called for a wrecker and met him at the track the next morning, only to find the aforementioned O-ring. So I spent $215 for a tow and had the problem repaired in 5 minutes after I got it back. Except as soon as I get it fixed, I find my 27 year old power steering pump finally failed, with power steering fluid dripping out on the floor. Ordered a new pump, and the reservoir was broke inside the box, but the company is sending me another pump and I don't have to send the broken one back. That's one plus, at least. I got it back together and went to start it, battery was totally dead. I had forgotten to turn off the exhaust cutout ( I keep it wide open at the track ) and the MAC valve was just sitting there powered up. So I had to charge it before I could get it running to check for leaks. It's back together and seemingly good, other than my brake booster being shot - I'm just going to wait until it's stored for the winter to attack that job. I guess I should be thankful that none of these issues presented themselves during my initial shakedown period, it's only been after I've been beating on the car awhile that things are popping up. Okay, end of rant! I'm hoping I can squeak out a 10 at the last event I'll be able to attend this year, if the weather cooperates. I'll get my GoPro out for that one.