Stage 2.5 5.3 heads on a 5.3?
01-08-2011, 10:28 AM
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Stage 2.5 5.3 heads on a 5.3? Have a 5.3 in my camaro
ls6 intake
longtubes
tr224 cam
3600 converter
3.42's
put down 320/338
Was looking at a set of stg 2.5 5.3 heads. Found a good used set for cheap, was thinking about milling them a bit as well to help bump the lousy compression of the 5.3.
What should I expect power wise? Really looking for that 400 mark.
ls6 intake
longtubes
tr224 cam
3600 converter
3.42's
put down 320/338
Was looking at a set of stg 2.5 5.3 heads. Found a good used set for cheap, was thinking about milling them a bit as well to help bump the lousy compression of the 5.3.
What should I expect power wise? Really looking for that 400 mark.
01-08-2011, 01:38 PM
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Id like to put the 4.8 pistons in, but I was really trying to keep the motor in the car this year, lol. Ive had it out the last 3 winters in a row, haha. Its got around 100k on it now. I assume I cant just grab some 4.8 pistons and drop them in? Wouldnt I need do all the measurements, hone the cylinders etc?
At that point, id just go get an lq4, seems like itd be more cost effective?
At that point, id just go get an lq4, seems like itd be more cost effective?
01-08-2011, 03:33 PM
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lq4/9 with ported 243's(or hell even milled and ported 317's). don't waste your time with that high mileage l33. i mean unless you are just dead set on making a **** hot l33....
01-09-2011, 12:06 PM
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Im trying to stay on the cheap.
Theres nothing wrong with my motor other than the miles, but there are plenty of HCI ls's with over 100k.
Just wondering how much im realistically looking at picking up if I slapped a set of milled prc 2.5 5.3 heads on.
Theres nothing wrong with my motor other than the miles, but there are plenty of HCI ls's with over 100k.
Just wondering how much im realistically looking at picking up if I slapped a set of milled prc 2.5 5.3 heads on.
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01-09-2011, 05:28 PM
#8
Id like to put the 4.8 pistons in, but I was really trying to keep the motor in the car this year, lol. Ive had it out the last 3 winters in a row, haha. Its got around 100k on it now. I assume I cant just grab some 4.8 pistons and drop them in? Wouldnt I need do all the measurements, hone the cylinders etc?
At that point, id just go get an lq4, seems like itd be more cost effective?
At that point, id just go get an lq4, seems like itd be more cost effective?
01-10-2011, 08:56 AM
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Hm, so a set of 4.8 pistons, some new rings, and possibly bearings and were back on the road eh?
Interesting thought.
Is 400 possible out of this thing NA? Or should I just spray what I have and call it a day?
Interesting thought.
Is 400 possible out of this thing NA? Or should I just spray what I have and call it a day?
01-10-2011, 11:51 AM
#10
I say go for the heads, mill them to 58cc's, and use some 0.040" thick gaskets. This should get your DCR up a touch over 8:1 which is much better than the 7.4ish you currently have. I don't think you will see much over 380 rwhp, but that's a nice bump over what you have now.
03-25-2011, 11:42 AM
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i know i'm bumping up a HELLA old thread... but I didn't want to make a new post if someone else had something similar.
Going for a similar build here (LM7, PRC 2.5 5.3's, LR4/L33 Flat tops) my question is are there any PTV clearance issues if the prc's are milled down to the 58 cc's? My original plan is to swap in the Wiseco 5.3 pistons with the valve reliefs cut in, but if that is not necessary, then I would rather take the cheaper route if i didn't have to drop 600 dollars on a set of forged pistons on a head & cam only motor.
Disclaimer: yes i understand buying a bigger bore engine would make more power in the end- but i got this engine for free basically.
Budget build FTW
Going for a similar build here (LM7, PRC 2.5 5.3's, LR4/L33 Flat tops) my question is are there any PTV clearance issues if the prc's are milled down to the 58 cc's? My original plan is to swap in the Wiseco 5.3 pistons with the valve reliefs cut in, but if that is not necessary, then I would rather take the cheaper route if i didn't have to drop 600 dollars on a set of forged pistons on a head & cam only motor.
Disclaimer: yes i understand buying a bigger bore engine would make more power in the end- but i got this engine for free basically.
Budget build FTW
03-25-2011, 01:01 PM
#20
i know i'm bumping up a HELLA old thread... but I didn't want to make a new post if someone else had something similar.
Going for a similar build here (LM7, PRC 2.5 5.3's, LR4/L33 Flat tops) my question is are there any PTV clearance issues if the prc's are milled down to the 58 cc's? My original plan is to swap in the Wiseco 5.3 pistons with the valve reliefs cut in, but if that is not necessary, then I would rather take the cheaper route if i didn't have to drop 600 dollars on a set of forged pistons on a head & cam only motor.
Disclaimer: yes i understand buying a bigger bore engine would make more power in the end- but i got this engine for free basically.
Budget build FTW
Going for a similar build here (LM7, PRC 2.5 5.3's, LR4/L33 Flat tops) my question is are there any PTV clearance issues if the prc's are milled down to the 58 cc's? My original plan is to swap in the Wiseco 5.3 pistons with the valve reliefs cut in, but if that is not necessary, then I would rather take the cheaper route if i didn't have to drop 600 dollars on a set of forged pistons on a head & cam only motor.
Disclaimer: yes i understand buying a bigger bore engine would make more power in the end- but i got this engine for free basically.
Budget build FTW
You will have enough room to run a 224/224ish cam which is plenty for a 5.3. I just built this exact setup using stock heads milled 0.030" with an .040 gasket and 224/224-112+4 cam. PTV was .12x intake/.14x exhaust. The larger valves on the ported heads will reduce PTV some but you should be fine.
It's always a good idea to check your actual PTV as variances in deck height and valve height on the seat can be different. I only quoted my measurements to give you an idea of what to expect.