5.3L Stroker Theoretical Tow Build
5.3L Stroker Theoretical Tow Build Yes I searched and its only theoretical until I have all the cash!!!! This will be in an 01 Suburban with a 4L80 and 4.11 rear gear. Maximum tow weight of 8k pounds. Goal is to pull that load down the hwy at 65mph with ease and laugh at the north GA mountains.
I had thought about buying a LQ4 and just swapping it out, but the cost of that isnt much less than building this. I will be keeping the stock 5.3L for a different project
Most people go with a 383 and called it a day. I'd like to start out with a 3.903 bored out 5.3L block which would make a 395 cid with a 4.125 crank. This will leave a lot of room for rebuilding down the road (read several threads with the block at 4.065 bore) and is a massive increase over 325 cid.
Texas speed has this kit covered up with wiseco pistons and balanced rotating assembly for $2500 with bearings!!
So on to the top end. With some 317 heads at 71cc and the -11cc pistons it should be right around 10:1 CR. Safe for 87 octane. Considering that most of the desired rpm use will be low, I think stock heads will flow just fine. Most ported heads dont improve flow that much under .400 lift anyway.
Which brings us to the cam. I am thinking a 212/226 on a 115 should help promote low end grunt and still make plenty of power everywhere else. I'll honestly leave the thing shifting at 5.5k rpm.
Stock truck/TBSS intake with a 90mm TB should work nicely for the added cubes. It will already have 1-3/4 long tubes on it as well. Might need to step up to 1-7/8 at that point but with such a low operating rpm I doubt it.
I'd like to think a combo like this should be able to run for a solid 100K miles or more. Thoughts? Anyone built anything similar? I'd like to make about 400ft/lb by 2500 rpm. Probably do a CD 278mm 2800 stall speed verter to keep heat down and help build torque fast.
I had thought about buying a LQ4 and just swapping it out, but the cost of that isnt much less than building this. I will be keeping the stock 5.3L for a different project
Most people go with a 383 and called it a day. I'd like to start out with a 3.903 bored out 5.3L block which would make a 395 cid with a 4.125 crank. This will leave a lot of room for rebuilding down the road (read several threads with the block at 4.065 bore) and is a massive increase over 325 cid.
Texas speed has this kit covered up with wiseco pistons and balanced rotating assembly for $2500 with bearings!!
So on to the top end. With some 317 heads at 71cc and the -11cc pistons it should be right around 10:1 CR. Safe for 87 octane. Considering that most of the desired rpm use will be low, I think stock heads will flow just fine. Most ported heads dont improve flow that much under .400 lift anyway.
Which brings us to the cam. I am thinking a 212/226 on a 115 should help promote low end grunt and still make plenty of power everywhere else. I'll honestly leave the thing shifting at 5.5k rpm.
Stock truck/TBSS intake with a 90mm TB should work nicely for the added cubes. It will already have 1-3/4 long tubes on it as well. Might need to step up to 1-7/8 at that point but with such a low operating rpm I doubt it.
I'd like to think a combo like this should be able to run for a solid 100K miles or more. Thoughts? Anyone built anything similar? I'd like to make about 400ft/lb by 2500 rpm. Probably do a CD 278mm 2800 stall speed verter to keep heat down and help build torque fast.
Last edited by Jenson; Jan 18, 2019 at 12:21 PM.
Sounds like a pretty good setup, cam might be a little bit much and but im not an expert on that with towing
Also not to sure about a stall in a 6,000lb vehicle towing 8,000 lbs
BUT, I have had the EXACT SAME ideas before and spent alot of time on it and to be honest, a small turbo will be BY FAR the best solution to your towing needs.
I do know that high PSI at to low of RPM is asking for trouble, but if you did a good set of pistons and rods, REALLY GOOD TUNE and could slowly bring boost in early it would pull like a diesel.
What gears are in your suburban?
Also not to sure about a stall in a 6,000lb vehicle towing 8,000 lbs
BUT, I have had the EXACT SAME ideas before and spent alot of time on it and to be honest, a small turbo will be BY FAR the best solution to your towing needs.
I do know that high PSI at to low of RPM is asking for trouble, but if you did a good set of pistons and rods, REALLY GOOD TUNE and could slowly bring boost in early it would pull like a diesel.
What gears are in your suburban?
Yeah you are right on the cam. That was more of a place holder and wild guess. I'll probably try to emulate the LS7 cam but on a 115 instead of 120.
I'm not sure on the converter at all either. A 278mm is big and shouldnt really make much heat with the smallest stator, I hope lol.
I thought about the whole turbo thing too, but btt you do a kit with A/C and build the engine (just pistons would work) you are looking at a lot more money than just building an engine. Plus more things to break/fail while you are in another state
Stock 3.73 gears right now with 32" tires. Cruises at 2000ish at 80mph
I'm not sure on the converter at all either. A 278mm is big and shouldnt really make much heat with the smallest stator, I hope lol.
I thought about the whole turbo thing too, but btt you do a kit with A/C and build the engine (just pistons would work) you are looking at a lot more money than just building an engine. Plus more things to break/fail while you are in another state
Stock 3.73 gears right now with 32" tires. Cruises at 2000ish at 80mph
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$2500 rotating assembly
$250 stock 317 heads
$250 Donor 5.3
$1000 machining and assembly
$500 for a 383 tune.
($4500 cost assuming you do your own R&R)
Swapping in an LQ4:
$900 LQ4 long block (already comes with 317s)
$100 VATS delete on the LQ4 stock PCM.
($1000 cost assuming you do your own R&R)
How exactly does that qualify as "cost of that isn't much less".
I haven’t figured compression, but with those 317’s and a -11cc dish piston, you’ll be in the high 8’s I’m guessing, and no where near what your thinking. I’m in the North Ga mountains that you referred to, and I’d go with a 6 liter build if you want torque. We are putting a 6liter build I just finished up in my brothers heavy 99’ 4x4 ext cab next week, and pulling the 5.3 out because he tows like you do, and the 5.3 just don’t cut it. At. All.
Edit...just saw your going 4.125 stroke, so figuring your compression this time around, you’re at 9.6. It would be more torquey, but with the small bore your limited to head selection. Start with the 6liter block, bore it .030” and you’ll have a much better tow rig.
The dished pistons are killing compression, and therefore torque. Go flattops, and get it up to around 11ish. Much better.
Edit...just saw your going 4.125 stroke, so figuring your compression this time around, you’re at 9.6. It would be more torquey, but with the small bore your limited to head selection. Start with the 6liter block, bore it .030” and you’ll have a much better tow rig.
The dished pistons are killing compression, and therefore torque. Go flattops, and get it up to around 11ish. Much better.
Last edited by Che70velle; Jan 18, 2019 at 04:28 PM. Reason: im retarted...
Nobody noticed he wants to do a 4.125 stroke on stock sleeves and have it last 100k (at least)? I'm not even sure it would make it out of the driveway.
OP while I understand your direction I don't think it's a good plan. I'd do a 6.0 or build a cheapo 6.2 if I were you. Take a 6.0 and bore it to 4.065 and put stock LS3 pistons in it ($300 with rings if I remember right) and do either cathedral or square heads.
OP while I understand your direction I don't think it's a good plan. I'd do a 6.0 or build a cheapo 6.2 if I were you. Take a 6.0 and bore it to 4.065 and put stock LS3 pistons in it ($300 with rings if I remember right) and do either cathedral or square heads.
Last edited by 00pooterSS; Jan 18, 2019 at 04:39 PM.
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Nobody noticed he wants to do a 4.125 stroke on stock sleeves and have it last 100k (at least)?
OP while I understand your direction I don't think it's a good plan. I'd build a cheapo 6.2 if I were you. Take a 6.0 and bore it to 4.065 and put stock LS3 pistons in it ($300 with rings if I remember right) and do either cathedral or square heads. Throwing vvt in somehow would be killer but not necessary.
OP while I understand your direction I don't think it's a good plan. I'd build a cheapo 6.2 if I were you. Take a 6.0 and bore it to 4.065 and put stock LS3 pistons in it ($300 with rings if I remember right) and do either cathedral or square heads. Throwing vvt in somehow would be killer but not necessary.
Agreed on the 6.2 build. Cubic inches is your friend for making torque.
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Two things:
1) 4.125" stroke in a stock block... no. It can be done. But it ain't lasting 100k miles. You can get the right piston for it to be decent and limit how much it rocks, but it's still going to come out of the end of the sleeve. 4.100" is a little better...
2) I don't believe you can't take a 5.3L block out past 3.980 or so. It still has iron liners that would be too thin.
I'd find an LQ4 and do one of the cheaper Compstar 5150 4" cranks with Scat I-Beam rods, and cheaper 4032 forged pistons. Build a 408. Use your truck intake. And use your stock cam. It'll make ungodly torque and die off at 5500 hard.
1) 4.125" stroke in a stock block... no. It can be done. But it ain't lasting 100k miles. You can get the right piston for it to be decent and limit how much it rocks, but it's still going to come out of the end of the sleeve. 4.100" is a little better...
2) I don't believe you can't take a 5.3L block out past 3.980 or so. It still has iron liners that would be too thin.
I'd find an LQ4 and do one of the cheaper Compstar 5150 4" cranks with Scat I-Beam rods, and cheaper 4032 forged pistons. Build a 408. Use your truck intake. And use your stock cam. It'll make ungodly torque and die off at 5500 hard.
Staging Lane
Joined: Jul 2017
Posts: 78
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From: Texas
Echoing the sentiments on a 4.125 stroke being too long. For a cheap budget build do the 6.0 swap and sell your 5.3. If you do that and find you still need more you can go with the 408 that is tried and true for about the same cost as the 5.3 you described above and it will be much more durable for towing.
Building a 5.3 into a stroker:
$2500 rotating assembly
$250 stock 317 heads
$250 Donor 5.3
$1000 machining and assembly
$500 for a 383 tune.
($4500 cost assuming you do your own R&R)
Swapping in an LQ4:
$900 LQ4 long block (already comes with 317s)
$100 VATS delete on the LQ4 stock PCM.
($1000 cost assuming you do your own R&R)
How exactly does that qualify as "cost of that isn't much less".
$2500 rotating assembly
$250 stock 317 heads
$250 Donor 5.3
$1000 machining and assembly
$500 for a 383 tune.
($4500 cost assuming you do your own R&R)
Swapping in an LQ4:
$900 LQ4 long block (already comes with 317s)
$100 VATS delete on the LQ4 stock PCM.
($1000 cost assuming you do your own R&R)
How exactly does that qualify as "cost of that isn't much less".
Two things:
1) 4.125" stroke in a stock block... no. It can be done. But it ain't lasting 100k miles. You can get the right piston for it to be decent and limit how much it rocks, but it's still going to come out of the end of the sleeve. 4.100" is a little better...
2) I don't believe you can't take a 5.3L block out past 3.980 or so. It still has iron liners that would be too thin.
I'd find an LQ4 and do one of the cheaper Compstar 5150 4" cranks with Scat I-Beam rods, and cheaper 4032 forged pistons. Build a 408. Use your truck intake. And use your stock cam. It'll make ungodly torque and die off at 5500 hard.
1) 4.125" stroke in a stock block... no. It can be done. But it ain't lasting 100k miles. You can get the right piston for it to be decent and limit how much it rocks, but it's still going to come out of the end of the sleeve. 4.100" is a little better...
2) I don't believe you can't take a 5.3L block out past 3.980 or so. It still has iron liners that would be too thin.
I'd find an LQ4 and do one of the cheaper Compstar 5150 4" cranks with Scat I-Beam rods, and cheaper 4032 forged pistons. Build a 408. Use your truck intake. And use your stock cam. It'll make ungodly torque and die off at 5500 hard.
Nobody noticed he wants to do a 4.125 stroke on stock sleeves and have it last 100k (at least)? I'm not even sure it would make it out of the driveway.
OP while I understand your direction I don't think it's a good plan. I'd do a 6.0 or build a cheapo 6.2 if I were you. Take a 6.0 and bore it to 4.065 and put stock LS3 pistons in it ($300 with rings if I remember right) and do either cathedral or square heads.
OP while I understand your direction I don't think it's a good plan. I'd do a 6.0 or build a cheapo 6.2 if I were you. Take a 6.0 and bore it to 4.065 and put stock LS3 pistons in it ($300 with rings if I remember right) and do either cathedral or square heads.
A little background, this is the first time in my life that my tow vehicle is not a cummins diesel. Ive had 4 manual cummins, 2 x 3500 dually's with 4.11 and 2 x 2500's. Then another 3 with auto trans. So naturally my first thought was to swap in a cummins but cooler heads prevailed lol.
Build the 5.3 into a 5.7. Put in a tow cam. dont be afraid of lift. Use some ported 4.8/5.3 heads.
Make some decent compression and have fun. keep the lsa tight also.
I tow ALOT like 6k to 20k with my 3 2500hd trucks. they love the tsp stage 2 high lift cam.
Our high lift hot cam makes for a good powerband also BUT in a 5.3 might be too high on the rpm range for a decent tow cam. the 5.3 just lack so much.
Going to a 4 inch stroke is fine but dont waste time with a small bore. build the 383 if you want any stroker. keep the cam small still and the lsa tight and youll be fine.
Ive towed 17klbs over 7hrs straight and 26k 4 hrs one way so i know just a little about all of that.
Make some decent compression and have fun. keep the lsa tight also.
I tow ALOT like 6k to 20k with my 3 2500hd trucks. they love the tsp stage 2 high lift cam.
Our high lift hot cam makes for a good powerband also BUT in a 5.3 might be too high on the rpm range for a decent tow cam. the 5.3 just lack so much.
Going to a 4 inch stroke is fine but dont waste time with a small bore. build the 383 if you want any stroker. keep the cam small still and the lsa tight and youll be fine.
Ive towed 17klbs over 7hrs straight and 26k 4 hrs one way so i know just a little about all of that.
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Joined: Jan 2008
Posts: 2,235
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From: Ohio, Georgia, Nevada, Texas
4" crank and 3.903 bore is a good plan for the money. Agreed on compression around 10. You may want to consider the new SUM-8719 Stage 1 truck cam (209/217 112 +1 .550 lift). A little bowl work and a nice valve job on the heads and the engine will be killer and easy on things for the long haul.
Ive ran the tsp stg2 high lift in my 2500hd trucks one 4l80 one nv4500 for nearly 20k miles a piece. i use the pac1218s on them. sometimes i run them HARD and they never miss a beat. youll enjoy the added lift i assure you as ive tried about 5 different cams.
I am in Jefferson/Braselton area.
Thanks for the real world info WS6store. I imagine your setup is a 6.0L with a cam? I can port the heads myself but like I said, they rarely do much better than stock below 400 anyway. Sometimes around 300 you get 20cfm bump and 200 can see 5-10ish but I have never done any truck heads, only 241, 243, and 821's. I am not a pro but I have a flow bench so I can test back to back. I will of course play around with them when the time comes but I wont spend money on a set as the cost will not reward power enough down low. I'll probably run an LSG or LXL lobe so lift will be 600ish so that it will be operating majority of the time around 400ish lift. Maybe I can get lucky and find a cheap Lq4 bloc, heck I sold one 4 years ago for $100 that would be perfect! But if that happens then I could run a set of LS3 heads which do flow alot better down low and every where.
We did pick out a camper this weekend (the 8k pounds to be towed I referred to) and its GVWR is 7500. It is 6k pounds unloaded and basically 29ft long. Its a Grand Design 2400BH if anyone really wanted to know. I probably shouldve sprung for the 2500 burban I looked at but it had 331k miles and was in terrible shape compared to this one. Other than my 26k mile 01 SS I bought in 05, this is the nicest used car I have ever bought. 3rd owner but the 2cd only had it for 30k miles. First owner took it to the dealer all the time and only one person there ever worked on it for the documented 185k miles they serviced it.
Thanks for the real world info WS6store. I imagine your setup is a 6.0L with a cam? I can port the heads myself but like I said, they rarely do much better than stock below 400 anyway. Sometimes around 300 you get 20cfm bump and 200 can see 5-10ish but I have never done any truck heads, only 241, 243, and 821's. I am not a pro but I have a flow bench so I can test back to back. I will of course play around with them when the time comes but I wont spend money on a set as the cost will not reward power enough down low. I'll probably run an LSG or LXL lobe so lift will be 600ish so that it will be operating majority of the time around 400ish lift. Maybe I can get lucky and find a cheap Lq4 bloc, heck I sold one 4 years ago for $100 that would be perfect! But if that happens then I could run a set of LS3 heads which do flow alot better down low and every where.
We did pick out a camper this weekend (the 8k pounds to be towed I referred to) and its GVWR is 7500. It is 6k pounds unloaded and basically 29ft long. Its a Grand Design 2400BH if anyone really wanted to know. I probably shouldve sprung for the 2500 burban I looked at but it had 331k miles and was in terrible shape compared to this one. Other than my 26k mile 01 SS I bought in 05, this is the nicest used car I have ever bought. 3rd owner but the 2cd only had it for 30k miles. First owner took it to the dealer all the time and only one person there ever worked on it for the documented 185k miles they serviced it.
Yes 6.0s. ive driven and installed them in 5.3s also. bring the cr up with a flat top or an ls1 bore and they really come to life.
Dont hand port. serious waste of time and money. send to tsp for their 2.5 program and rock and roll. id use the stock chamber size tho.
Id find a locked up or oil burner 6.0 and rebuild it honestly. you'll get em cheap enough then and not be putting another tired engine into that spot. i always buy engines with the intent to rebuild them so any low hanging fruit will do. if the crank and rods are good, then have at it.
Dont hand port. serious waste of time and money. send to tsp for their 2.5 program and rock and roll. id use the stock chamber size tho.
Id find a locked up or oil burner 6.0 and rebuild it honestly. you'll get em cheap enough then and not be putting another tired engine into that spot. i always buy engines with the intent to rebuild them so any low hanging fruit will do. if the crank and rods are good, then have at it.
Yes 6.0s. ive driven and installed them in 5.3s also. bring the cr up with a flat top or an ls1 bore and they really come to life.
Dont hand port. serious waste of time and money. send to tsp for their 2.5 program and rock and roll. id use the stock chamber size tho.
Id find a locked up or oil burner 6.0 and rebuild it honestly. you'll get em cheap enough then and not be putting another tired engine into that spot. i always buy engines with the intent to rebuild them so any low hanging fruit will do. if the crank and rods are good, then have at it.
Dont hand port. serious waste of time and money. send to tsp for their 2.5 program and rock and roll. id use the stock chamber size tho.
Id find a locked up or oil burner 6.0 and rebuild it honestly. you'll get em cheap enough then and not be putting another tired engine into that spot. i always buy engines with the intent to rebuild them so any low hanging fruit will do. if the crank and rods are good, then have at it.
Hey summit, how much can your 5.3L blocks be bored out to? Or will you be offering a 6.0L block any time soon?
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Posts: 2,235
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From: Ohio, Georgia, Nevada, Texas
I dont even need those to be good, just the block itself to be intact, especially if its going to 4.065 bore. My only hangup there is that the block would be done. If you go with a 4.00" bore first and that gets tired you can then step up to 4.005, then 4.03, then 4.065. Also have you done a converter in any of the 80 equipped trucks?
Hey summit, how much can your 5.3L blocks be bored out to? Or will you be offering a 6.0L block any time soon?
Hey summit, how much can your 5.3L blocks be bored out to? Or will you be offering a 6.0L block any time soon?