5.3 For racing
10-19-2017, 08:36 AM
#1
5.3 For racing
Alright Guys the time has come as my ole High comp 350 is dying a slow death.
I have 2- iron block 5.3's
the one i will be using for this build is a 99'
Block has been to the machine shop,
fresh hone (not bored)
new cam bearings
new main bearings
polished crank (no grind)
Heads were shaved .015" for flat
The jeep weighs around 3200lbs, has 3.73 axle gears, and will be spinning a TH350 trans with a ACI low Planet set, Bringing the Final ratio closer to 4:10s
I have the following parts ive already purchased as i was starting this build a while back
Competition Cams 54-426-11 XFIRPM Hi-Lift XR275HR-12
COMP Cams 26918-16 Beehive 1.075"/1.310" O.D. Valve Spring
My thoughts and questions:
4.8 Pistons ( speed pro, hypereutectic)
send the heads to TEA for their 5.3 port package...
SLP oil pump
comp double roller chain
Arp Rod bolts?
Gm performance lifters and trays
Summit racing Trunion bearing upgrade
How hard can i spin this thing?
Using stock GM head gaskets, is PTV going to be an issue?
With the shaved heads, and flat top pistons what compression ratio can i expect?
3000 stall? 3500 stall?
Any suggestions/comments or opinions on how much HP this thing will make
The motor will spend a lot of life wide open, my current 350 gets spun too 6800 all the time
( first LS build, excited to go injected as carbs and i just dont get along)
I have 2- iron block 5.3's
the one i will be using for this build is a 99'
Block has been to the machine shop,
fresh hone (not bored)
new cam bearings
new main bearings
polished crank (no grind)
Heads were shaved .015" for flat
The jeep weighs around 3200lbs, has 3.73 axle gears, and will be spinning a TH350 trans with a ACI low Planet set, Bringing the Final ratio closer to 4:10s
I have the following parts ive already purchased as i was starting this build a while back
Competition Cams 54-426-11 XFIRPM Hi-Lift XR275HR-12
COMP Cams 26918-16 Beehive 1.075"/1.310" O.D. Valve Spring
My thoughts and questions:
4.8 Pistons ( speed pro, hypereutectic)
send the heads to TEA for their 5.3 port package...
SLP oil pump
comp double roller chain
Arp Rod bolts?
Gm performance lifters and trays
Summit racing Trunion bearing upgrade
How hard can i spin this thing?
Using stock GM head gaskets, is PTV going to be an issue?
With the shaved heads, and flat top pistons what compression ratio can i expect?
3000 stall? 3500 stall?
Any suggestions/comments or opinions on how much HP this thing will make
The motor will spend a lot of life wide open, my current 350 gets spun too 6800 all the time
( first LS build, excited to go injected as carbs and i just dont get along)
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captnviper (11-22-2017)
10-19-2017, 12:26 PM
#4
Since he mentioned stall converters and it's going in a jeep, I'm guessing drag racing of some sort. Either dirt or pavement. The cam choice I like, but it's a fairly mild cam, so I'm assuming this rig will be doing more than just strip racing.
The list the OP put out seems pretty solid for an engine build and if anything is probably overkill. The difference in power between 6500 that a SBE motor can safely handle and 6800 isn't that great considering the cost. It really comes down to what the priorities are in the budget and by what the performance standards are. The old small block days pretty much required engines to be "built" with all kinds of expensive parts to handle big power. But the LS platform has proven to stand up to a lot more abuse in stock form. A nice heads/cam/intake setup with a wide open exhaust go a long way and do it dependably.
The list the OP put out seems pretty solid for an engine build and if anything is probably overkill. The difference in power between 6500 that a SBE motor can safely handle and 6800 isn't that great considering the cost. It really comes down to what the priorities are in the budget and by what the performance standards are. The old small block days pretty much required engines to be "built" with all kinds of expensive parts to handle big power. But the LS platform has proven to stand up to a lot more abuse in stock form. A nice heads/cam/intake setup with a wide open exhaust go a long way and do it dependably.
Last edited by BudRacing; 10-19-2017 at 12:35 PM.
10-19-2017, 01:15 PM
#7
Since he mentioned stall converters and it's going in a jeep, I'm guessing drag racing of some sort. Either dirt or pavement. The cam choice I like, but it's a fairly mild cam, so I'm assuming this rig will be doing more than just strip racing.
The list the OP put out seems pretty solid for an engine build and if anything is probably overkill. The difference in power between 6500 that a SBE motor can safely handle and 6800 isn't that great considering the cost. It really comes down to what the priorities are in the budget and by what the performance standards are. The old small block days pretty much required engines to be "built" with all kinds of expensive parts to handle big power. But the LS platform has proven to stand up to a lot more abuse in stock form. A nice heads/cam/intake setup with a wide open exhaust go a long way and do it dependably.
The list the OP put out seems pretty solid for an engine build and if anything is probably overkill. The difference in power between 6500 that a SBE motor can safely handle and 6800 isn't that great considering the cost. It really comes down to what the priorities are in the budget and by what the performance standards are. The old small block days pretty much required engines to be "built" with all kinds of expensive parts to handle big power. But the LS platform has proven to stand up to a lot more abuse in stock form. A nice heads/cam/intake setup with a wide open exhaust go a long way and do it dependably.
The motor is already torn down, so i was just thinking if i could add rod bolts and safely spin to 7-7200 it might be a worthwhile investment, if i have to spent 3000$ to spin to 7200 we will stick with the 6500 limit ha ha
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10-19-2017, 01:15 PM
#8
for a mild NA build, are the factory rods a problem?
10-19-2017, 01:20 PM
#9
The last thing I think would be an issue is the rod bolts. The rod always breaks before a rod bolt does.
Without it on a dyno you wouldn't know where the cam stops making power on your setup. For all we know it could stop making peak power and torque at 6000-6400 so spinning to 7000+ would be useless.
Without it on a dyno you wouldn't know where the cam stops making power on your setup. For all we know it could stop making peak power and torque at 6000-6400 so spinning to 7000+ would be useless.
10-19-2017, 01:45 PM
#10
That statement makes no sense at all.
A cam controls valve events and the varied relation of intake to exhaust. Within the LS platform, a cam of the same profile can be used in a 4.8, 5.3, 5.7, 6.0, a 6.2, or even one of the LSX aftermarket blocks. (extreme examples of PTV clearance issues exempt) Compatibility varies due to 2 vs 3 bolt designs and cam sprockets. The difference lies in the power they make because there's no replacement for displacement.
Cam Spec Terms - Lunati Power
"Big" may refer to a cam's lift profile. But I would consider the mid .5xx's a mild lift as many are above .600". This is a good thing, because the higher the lift, the more stressed the valve springs are. Stress over time leads to breakage and valves dropping onto moving pistons--**** hits the fan.
The cam you specified has the following specs according to Amazon:
275/277 Advertised Duration, 222/224 Duration @ .050 inch, .566 inch/.568 inch Lift, 112 Lobe Separation (LSA)
It's a cam I would run myself.
A cam controls valve events and the varied relation of intake to exhaust. Within the LS platform, a cam of the same profile can be used in a 4.8, 5.3, 5.7, 6.0, a 6.2, or even one of the LSX aftermarket blocks. (extreme examples of PTV clearance issues exempt) Compatibility varies due to 2 vs 3 bolt designs and cam sprockets. The difference lies in the power they make because there's no replacement for displacement.
Cam Spec Terms - Lunati Power
"Big" may refer to a cam's lift profile. But I would consider the mid .5xx's a mild lift as many are above .600". This is a good thing, because the higher the lift, the more stressed the valve springs are. Stress over time leads to breakage and valves dropping onto moving pistons--**** hits the fan.
The cam you specified has the following specs according to Amazon:
275/277 Advertised Duration, 222/224 Duration @ .050 inch, .566 inch/.568 inch Lift, 112 Lobe Separation (LSA)
It's a cam I would run myself.
