5.3L vs. 5.7L Heads
#4
FormerVendor
iTrader: (51)
Re: 5.3L vs. 5.7L Heads
</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Jimmyz:
<strong> The 4.8 & 5.3's offer no advantage over the LS1 head except for a smaller combustion chamber. If you mill the deck surface, it will let you achieve a slightly higher compression ratio. This is straight out of the May 2003 GMHTP Mag. </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Quit reading magazines and go build a damn motor <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />
<strong> The 4.8 & 5.3's offer no advantage over the LS1 head except for a smaller combustion chamber. If you mill the deck surface, it will let you achieve a slightly higher compression ratio. This is straight out of the May 2003 GMHTP Mag. </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Quit reading magazines and go build a damn motor <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />
#5
TECH Fanatic
iTrader: (3)
Re: 5.3L vs. 5.7L Heads
</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Cammin BeaSSt:
<strong> Quit reading magazines and go build a damn motor <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">That's really funny...I couldn't build a model airplane. <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />
<strong> Quit reading magazines and go build a damn motor <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">That's really funny...I couldn't build a model airplane. <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />
#6
Re: 5.3L vs. 5.7L Heads
So what's the sacrifice you make by increasing compression? If I am using 230/224 .575/.563 111 LSA cam and planning on maybe sprayin' in the future, a TNT 100 Wet Shot. I heard that with my setup I may smack a valve. <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" />
#7
On The Tree
Join Date: May 2002
Location: Daytona Fla
Posts: 108
Likes: 0
Received 0 Likes
on
0 Posts
Re: 5.3L vs. 5.7L Heads
The 5.3L heads have the same port volumes
the 5.3 has the same exhaust valve size but a smaller intake valve , however the seat is the same and can be machined to accept the 2.00" 5.7L intake valve the chambers are slightly smaller so you will see an increase in compression WITHOUT milling the head which might help you with V/P clearance good luck i have a set on the bench getting ready to go on soon I saw a buildup with a mild port job on these heads, a cam,bigger MAF and TB, long tubes, and LS1Edit programing - was putting down 500Hp at the wheels awesome <img border="0" alt="[burn out]" title="" src="graemlins/gr_burnout.gif" />
the 5.3 has the same exhaust valve size but a smaller intake valve , however the seat is the same and can be machined to accept the 2.00" 5.7L intake valve the chambers are slightly smaller so you will see an increase in compression WITHOUT milling the head which might help you with V/P clearance good luck i have a set on the bench getting ready to go on soon I saw a buildup with a mild port job on these heads, a cam,bigger MAF and TB, long tubes, and LS1Edit programing - was putting down 500Hp at the wheels awesome <img border="0" alt="[burn out]" title="" src="graemlins/gr_burnout.gif" />
Trending Topics
#9
On The Tree
Join Date: May 2002
Location: Daytona Fla
Posts: 108
Likes: 0
Received 0 Likes
on
0 Posts
Re: 5.3L vs. 5.7L Heads
compression = power! I`m gonna go with the 5.3L`s
you shouldnt have V/P clearance probs if you dont mill the heads too much.
PS; my old small block stroker is 12 to 1 comp never had any probs but it doesnt like pump gas - I mix 110 sunoco with 93 amoco half and half and it loves it <img border="0" alt="[burn out]" title="" src="graemlins/gr_burnout.gif" />
you shouldnt have V/P clearance probs if you dont mill the heads too much.
PS; my old small block stroker is 12 to 1 comp never had any probs but it doesnt like pump gas - I mix 110 sunoco with 93 amoco half and half and it loves it <img border="0" alt="[burn out]" title="" src="graemlins/gr_burnout.gif" />
#11
TECH Apprentice
Join Date: Jun 2002
Location: Bowling Green, KY
Posts: 321
Likes: 0
Received 0 Likes
on
0 Posts
Re: 5.3L vs. 5.7L Heads
The 5.3 head does flow better (asuming your talking ported) on the intake and exhaust. The 5.3 head builds compression without milling at all. This leaves you with a much larger piston to valve clearance. The 5.3 head flows 15cfm better than a 5.7 so it is a killer nitrous head. I hope I answered everything for ya, if not let me know.
#12
TECH Junkie
Join Date: Nov 2001
Location: Melbourne, FL
Posts: 3,987
Likes: 0
Received 0 Likes
on
0 Posts
Re: 5.3L vs. 5.7L Heads
</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by XLR8VRL:
<strong> I saw a buildup with a mild port job on these heads, a cam,bigger MAF and TB, long tubes, and LS1Edit programing - was putting down 500Hp at the wheels awesome <img border="0" alt="[burn out]" title="" src="graemlins/gr_burnout.gif" /> </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Where did you see that? Most of the big 420+ cid motors seem to only make a little over 500rwhp. I haven't had my ARE 382cid solid roller on a dyno, but it should be in the ~500rwhp range.
I think you saw/read something incorrectly. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />
<strong> I saw a buildup with a mild port job on these heads, a cam,bigger MAF and TB, long tubes, and LS1Edit programing - was putting down 500Hp at the wheels awesome <img border="0" alt="[burn out]" title="" src="graemlins/gr_burnout.gif" /> </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Where did you see that? Most of the big 420+ cid motors seem to only make a little over 500rwhp. I haven't had my ARE 382cid solid roller on a dyno, but it should be in the ~500rwhp range.
I think you saw/read something incorrectly. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />
#14
Re: 5.3L vs. 5.7L Heads
Thanks guys, these are the answers I've been looking to get for about 2 weeks now.
What if I sprayed with the TR230 cam I mentioned above and the 5.3L Stage 1.5?
Vince : I plan on using QTP's LT 1 3/4" Stainless Steel Race Style Headers, QTP's off-road y-pipe, to a Hooker Cat-back. Running dumps at the track. Do you think this will flow well enough?
What if I sprayed with the TR230 cam I mentioned above and the 5.3L Stage 1.5?
Vince : I plan on using QTP's LT 1 3/4" Stainless Steel Race Style Headers, QTP's off-road y-pipe, to a Hooker Cat-back. Running dumps at the track. Do you think this will flow well enough?
#16
TECH Junkie
Join Date: Dec 2001
Location: Lakeland, FL
Posts: 3,242
Likes: 0
Received 0 Likes
on
0 Posts
Re: 5.3L vs. 5.7L Heads
I know it was a fluke but after seeing what Vince went through with his 5.3 heads I am scared to use them although most people do get more power with them.
#19
Shorty Director
iTrader: (1)
Re: 5.3L vs. 5.7L Heads
I see no down falls with running the 5.3L head. Just be aware that milling them will increase compression and that will require a better tune to prevent detonation on pump gas.. A good tuner can give you killer #'s with these heads.. If I were to stay NA I would swap my heads for some 5.3L's and run higher compression. I also have valve reliefs, so milling them .050 would be fine for me even with my 232 cam.. Matching the exhaust is also important when building a setup.. You can have a killer H/C setup, but if your exhaust is your bottleneck you will never see your cars true potential..
#20
TECH Junkie
Join Date: Nov 2001
Location: Melbourne, FL
Posts: 3,987
Likes: 0
Received 0 Likes
on
0 Posts
Re: 5.3L vs. 5.7L Heads
</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by 98_WS6_M6:
<strong> So are there any downfalls at all to going with the ported 5.3L heads?
I heard that you were running the GeorgeC , what do you recommmend? </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I'm not an expert, but I do like the 5.3 heads. I used them on my current motor since the flow numbers are just as good as an LS1 head, and the smaller combustion chambers helped get the compression ratio we wanted (which is pretty high) w/o too many piston to valve clearance issues with the huge cam I'm running.
<strong> So are there any downfalls at all to going with the ported 5.3L heads?
I heard that you were running the GeorgeC , what do you recommmend? </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I'm not an expert, but I do like the 5.3 heads. I used them on my current motor since the flow numbers are just as good as an LS1 head, and the smaller combustion chambers helped get the compression ratio we wanted (which is pretty high) w/o too many piston to valve clearance issues with the huge cam I'm running.