yes it will change with an iron block and aluminum heads but not near ad much as aluminum block and heads. If i set lash at .010 hot when it cools down and temp is cold outside it will hang the valves open making starting harder.

 

That is with aluminum right? With iron I figure cold lash and hot lash are only a couple thou different

 

yes, with non ls iron block and aluminum heads i usually go .002 tighter on lash cold. Im not sure ls iron block with aluminum expansion amount. Set your lash at zero cold, get engine to temp and pull cover off and measure lash. That will give you the amount of expansion. Adjust accordingly.

 

Iron block/aluminum heads, rule of thumb is .006 growth. Aluminum block/aluminum heads can go .010 to .012, depending on aluminum makeup.

 

On my Ls1 setup they grew exactly 010. This setup they seem to grow 013. I thought it was the taller heads. Since expansion is based on original length. Its a theory anyway.

Effing raining today so nothing to report. I got more idle work to do. Def going to have to drill further. I cannot get counts down with timing or mixture. This thing is air-hungry like I never seen.

 

More air means more fuel and more power!
Keep on tuning

 

Yup^^^, its so cool seeing how exciting that is. I totally get it. Jake put together a nice combo, n its lookn very true right out the gate!!! Cant wait til he gets it dialed in n starts bangn gears n breakn dynos. Ok, maybe not breaking dynos, but how bout some hearts instead! Mamos world!

 

Once he gets it up and running we can all rub one out in honour of this project.

 

Lol. This ^^^^

 

Thanks guys. Got some more data, but it's raining, so I can't get anything more. Free-revving while working to control idle (still not quite there, I'll get to that), I got some data, and it's really promising.

Alot of you more savvy guys can compare this data to your own, and get a pretty good idea where we are. but when I say air-hungry, I mean air-hungry. Free revving to 4600, it hit 0.98 g/cyl. To put that in perspective, under full load at peak torque my 346 build made 1.04 g/cyl at its very best. But, this is no load. 60kpa MAP readings. and 4600 is not even peak torque. airflow is 280 g/sec. Again, free-revving, no load, 280 g/sec airflow. This thing could max out the ECU airflow under load by 5000 rpm.

For now, I need to keep working until I can stab the throttle and have it return to idle without surging and then I can start the street tuning. I have not checked the weather yet, but I severely hope it does not rain tomorrow. Even if it stops now, the roads are too wet at this point.

 

Time to Mcguever up a rolling road,...we need 2-50gallon drums, some 1 1/4" gas pipe lengths, roll of skate board grip tape...Merica!

 

Time for Holley hp it sounds like. Or very close to it. I may know a guy with one for sale for a good price.

 

Ditch the maf and go speed density tune take care of it, no aftermarket ecu needed? I was afraid of SD at first but t's really not that difficult once you begin. It is more time consuming than anything. Also my car idles a lot smoother since going SD , almost worth it just for the idle quality. I imagine with a much bigger cam SD will be even more beneficial.

 

He runs SD already. He has tuned my cars speed density as well as talked others into it. And you're definitely not wrong on not needing an aftermarket ecu. Darth is a genius with the stock ecu and HPtuners. Though there's still the hard limiter at 8200 until GPI releases how they cracked it or Darth figures it out. But I don't think he is going to spin it there anyway.

But anyways, I'm messing with him. We've had this conversation a bunch of times. I know Darth very well. And I have a brand new Holley HP I've been trying to get him or Hammer to buy lol.

 

@98 already answered it. But for more color...

I had found in my old 346 build I was pulling a vacuum under full power and traced it back to the card style mag blocking the airflow. Went SD. Ended up going OLSD so I could lean out the idle and better control off idle transitions, etc. then I found how to really get a good Alpha-N (throttle position vs rpm) blend into the mix, which REALLY helped smooth it out.

In this case, my main issue is this thing is simply air hungry and I need my IAC counts to come down. Maf vs SD makes no difference. I will need to drill the blade more to get flow so I can get the counts down. Nbd. But I wanted to exhaust all options first since it looks like if my math is right it will be a 5/16 hole, which is pretty big. But it wants 20 g/sec to idle.

 

What about the Holley TB with the adjustable sensors to get them back into the appropriate range?

 

I have my blade opened to .6 volts and kept resetting tp until I couldnt go any more resetting to 0% throttle.
still had to drill a 1/16 hole and still at 80 steps but idles great at 75kpa

 

Mine is at 0.69 v and nowhere near enough air even with a 13/64 hole
IAC too small. I tried dialing a few in. Bleeder is helpful, but IAC really needs to be more like the NW

 

Gonna need a bigger throttle body 😁

 

Maybe dual tb's? Or 8?