longblock came, now what heads??
03-09-2006, 02:03 PM
#1
longblock came, now what heads?? My longblock came (pics) from HPE last week.... it's a 346ci aluminum LS1 with a new stock cast iron crank, forged Scat I-beam rods, forged -8.66cc Diamond pistons, Mahle rings, Federal Mogul bearings, a stock 1999 Camaro cam and new stock timing gears with an LS2 chain. It was assembled with ARP main studs and rod bolts. The block was deburred, decked and honed with torque plates, crank recentered and the entire assembly was balanced. I THINK the compression ratio is 8.9:1 with a 317 truck head but not 100# sure... I need to get a build sheet or something off of Erik.
Now the question is, which heads? (BTW, I have 918 springs, hardened pushrods and Ti retainers) I have a set of 317 casting truck heads and a set of 98 vette heads. I will be using the 98 vette electical system, so I am limited to a 2 bar setup. Do you think I should still stay with the 317 heads w/bigger valves or should I go with the smaller chamber, higher compression and smaller valves of the 98 vette heads? This is going to be a street driven turbo car, and I plan on getting a valve job done with whichever heads I decide to use. I also want a safe tune!
Just want some opinions!
Thanks, -Dave
Edit: I know the forum rules (you guys like pics!) but they're too big to upload - check out my site for more pics:
http://www.buyrcars.com/jag.htm
Now the question is, which heads? (BTW, I have 918 springs, hardened pushrods and Ti retainers) I have a set of 317 casting truck heads and a set of 98 vette heads. I will be using the 98 vette electical system, so I am limited to a 2 bar setup. Do you think I should still stay with the 317 heads w/bigger valves or should I go with the smaller chamber, higher compression and smaller valves of the 98 vette heads? This is going to be a street driven turbo car, and I plan on getting a valve job done with whichever heads I decide to use. I also want a safe tune!
Just want some opinions!
Thanks, -Dave
Edit: I know the forum rules (you guys like pics!) but they're too big to upload - check out my site for more pics:
http://www.buyrcars.com/jag.htm
Last edited by FastKat; 03-09-2006 at 02:14 PM.
03-09-2006, 02:22 PM
#2
Hey man....I spoke to you a while ago...So you got it now...that's really cool...I would go with the 6.0 heads personally and that's what I'm going with too...How much boost are you wanting to run?? I know that you are "limited" to 14.7psi (for the time being until some more tuning options come available) but what do you think that you will be turning it up to???
03-09-2006, 02:39 PM
#3
Hey! Not sure, I wonder where 12 or 13 psi will put me? I do have to push through my 4L80E and a pretty heavy duty Dana 44 rear end so I wonder what kind of numbers I'll be putting down at the rear wheels at those boost levels.
I couldn't see going past a 12 or 13 psi... if I had some sort of surge past 14.7 psi and I ran out of fuel, BOOM! I don't want that to happen to me! Plus I want to be able to mercilessly beat on this drivetrain... I went heavy duty for a reason!
I couldn't see going past a 12 or 13 psi... if I had some sort of surge past 14.7 psi and I ran out of fuel, BOOM! I don't want that to happen to me! Plus I want to be able to mercilessly beat on this drivetrain... I went heavy duty for a reason!
Originally Posted by 98turbls1
Hey man....I spoke to you a while ago...So you got it now...that's really cool...I would go with the 6.0 heads personally and that's what I'm going with too...How much boost are you wanting to run?? I know that you are "limited" to 14.7psi (for the time being until some more tuning options come available) but what do you think that you will be turning it up to???
03-09-2006, 02:52 PM
#4
Hell yeah man....You could probably run the 12-13psi with pump gas if you had lower compression but if you're at 8.9:1cr with the 6.0 heads then you'll probably be pushing high 9.x cr if you went with the other head....Plus you never know if you get a wild hair up your butt and go to a BS3\maf t pro\etc and be able to boost higher...Obviously not on pump gas but just some added reassurance...Goodluck man, I remember when you first ordered this thing...You were pretty stoked about it....Still looking for me =( ..The shortblocks keep getting more expensive as I look too...I better hurry up and get one before it's $10k for my shortblock alone....hehe...=) I'll be home next month so I'll be able to tinker a little with it and actually be able to call people in person instead of emailing people and hope that they email me back...Are you shooting for a certain amount of hp or times or just seat of the pants??
03-09-2006, 02:55 PM
#5
Wait a sec man...Aren't the 72cc supposed to drop you to 9.0:1 from 10.0:1 on a stock engine and they have -2cc pistons I believe....You should be down around 8.5:1 or maybe even a little lower...Hmmm, I'm going to have to research this for you...=) What else do I really have to do?? I"m in Iraq!!!
03-09-2006, 03:24 PM
#6
Yea, it's been so long I honestly can't remember what CR I had built. I will have to email Erik and get a build sheet for my block... it was somewhere between 8.9:1 and 8.5:1. Do you think 8.9:1 will limit me to 9 psi?
Originally Posted by 98turbls1
Wait a sec man...Aren't the 72cc supposed to drop you to 9.0:1 from 10.0:1 on a stock engine and they have -2cc pistons I believe....You should be down around 8.5:1 or maybe even a little lower...Hmmm, I'm going to have to research this for you...=) What else do I really have to do?? I"m in Iraq!!!
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03-09-2006, 04:10 PM
#10
Yes, I am planning an A2W intercooler... I have given a lot of thought to not running one (Banks style!!) however I don't want to mess with water or meth injection... that's one more system in my car that can potentially fail.
If going from a 68cc? to a 72cc head drops your CR ratio down to 9.5:1, it sounds like a -8.66cc dish may bring me down closer to the 8.5:1 mark.
If going from a 68cc? to a 72cc head drops your CR ratio down to 9.5:1, it sounds like a -8.66cc dish may bring me down closer to the 8.5:1 mark.
03-09-2006, 04:25 PM
#11
That's what I was thinking man...If so then I would definitely turn that boost up a little more...soooo what are you going to do about the summer months??? I hear that a A2W IC is great for the track and stuff but on the street during the summer months it doesn't cool as well....I guess you can get all of that figured out in the mean time...Another thing that you could do is maybe go with a thicker gasket to drop it a little more IF needed....
03-09-2006, 05:52 PM
#12
stock ls1 heads are like 64-65cc's so thats why it drops the compression so much.I dont think ur 8.5:1 or lower.i think ur about 8.8-9:1 but id need the rest of the specs.And if u dont want to worry about another thing to fail then why not go A2A,less hassle,better for a dd or streetcar.A2W is better for the track as stated.Motor looks good though.I started tearing mine down as well.Got a thread about the progress.good luck
03-09-2006, 11:00 PM
#13
Awesome, I'll keep an eye out for your thread. Believe me, I seriously wish I could run an A2A but I don't have much of a choice. There's no good mounting place on my Jag... barely enough room for a heat exchanger. The rad and condensor take up all the room up front. Plus the fact that the rad is straight up and down will make it a little more difficult to plumb into the throttle body without some sharp 90 degree bends. Even if I put the intercooler right in front of the rad, I would have heat soak and a heck of a time getting it over the hot radiator into the throttle body.
However, I'll cross that bridge when I come to it... right now I just want to get the d@mn engine and trans mounted in the right spot!
However, I'll cross that bridge when I come to it... right now I just want to get the d@mn engine and trans mounted in the right spot!
