4 inch crank into a ls1
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So going with these pistons is fine? my compression ratio will still be in the 9.5 - 10 range? I thought going with these pistons and the 6.125 rods would bring the piston further up to the valves on the compression stroke and therefore raise the compression? eventually I will be boosting with a single turbo so I wanted to keep the compression down in anticipation of boosting in the future. So these forged pistons are good for my application correct? now Im going to search for a deal on forged rods with .927 pin diameter and a 6.125 length and that set up should keep my compression in the 9'ish range, is that accurate? thank you in advance for the advice.
http://www.wallaceracing.com/cr_test2.php
IMO, the best bang for the buck rod would be the Scat I Beam. WS6Store has them for about $300 a set. They are forged 4340 steel, use 7/16" ARP bolts, and can handle a good amount of power. The pin bores are a little tight for a forced induction application, but that's an easy cheap fix for your machinist.
IMO, the best bang for the buck rod would be the Scat I Beam. WS6Store has them for about $300 a set. They are forged 4340 steel, use 7/16" ARP bolts
These are the ones I used...
Teching In
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How's it everyone, so my build might take a slightly different direction depending on the extent of the work that needs to be done, I had no intensions of changing out my stock crank for a 4" but I might be able too get a LS7 crankshaft for less than a third of what it would cost to buy a new Eagle 4" stroke crank so thats why I am now considering this option, my question is what machine work will need to be done, supposedly the front needs too be machined down which seems logical being that the LS7 is slightly longer but will I be able to stick with the wet sump or will I have to convert to dry sump. My major parts acquisition is almost complete but luckily the only parts I have for the rotating assembly is the Mahle 3.903 pistons, I haven't ordered the rods or any of the bearing because I wanted to get the block into the machine shop and have them clean it up and check for clearances then order accordingly. Thanks for the replies!
Teching In
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Thats a very handy link thank you. I have the stock 862 heads which have been redone, 3 angle, new larger stainless intakes and exhaust, new seals seats retainers and a set of PAC springs. A friend of a friend did a mild porting and it looks pretty smooth. I wish I had done a little more research on my build before sending out the 862 heads had I known that the 317's would have been a better candidate too get redone for the lower compression, Ill make due with my 862's and maybe look into upgrading them in the future. I might possibly do a different direction on the crank shaft. I may have a line on acquiring a LS7 crank for less than 1/3 the cost of a new Eagle 4" stroke crank so Im considering going the 4" stroke route if the work involved is not cost prohibitive.
I don't know what heads you're wanting to use, so I can't tell you what your compression will be. However, with these pistons, the 6.125" rods, and the stock 5.3L heads, like an 862 or 706 casting, you would be right around 10:1 but swapping to a 317 casting would drop it down to about 9:1. I use this online calculator to come up with compression ratios:
http://www.wallaceracing.com/cr_test2.php
IMO, the best bang for the buck rod would be the Scat I Beam. WS6Store has them for about $300 a set. They are forged 4340 steel, use 7/16" ARP bolts, and can handle a good amount of power. The pin bores are a little tight for a forced induction application, but that's an easy cheap fix for your machinist.
http://www.wallaceracing.com/cr_test2.php
IMO, the best bang for the buck rod would be the Scat I Beam. WS6Store has them for about $300 a set. They are forged 4340 steel, use 7/16" ARP bolts, and can handle a good amount of power. The pin bores are a little tight for a forced induction application, but that's an easy cheap fix for your machinist.
How's it everyone, so my build might take a slightly different direction depending on the extent of the work that needs to be done, I had no intensions of changing out my stock crank for a 4" but I might be able too get a LS7 crankshaft for less than a third of what it would cost to buy a new Eagle 4" stroke crank so thats why I am now considering this option, my question is what machine work will need to be done, supposedly the front needs too be machined down which seems logical being that the LS7 is slightly longer but will I be able to stick with the wet sump or will I have to convert to dry sump. My major parts acquisition is almost complete but luckily the only parts I have for the rotating assembly is the Mahle 3.903 pistons, I haven't ordered the rods or any of the bearing because I wanted to get the block into the machine shop and have them clean it up and check for clearances then order accordingly. Thanks for the replies!
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The LS7 crank is a trap for many people. It's a cheap 4" stroke crank, so many think they can just add some cheap rods and pistons and have a cheap stroker. The problem is when it comes time to balance everything. The LS7 uses lightweight titanium rods so they're balanced for a very light bobweight. In order to get the crank to balance with heavier steel rods, you may end up paying $400 or more to have heavy metal added to the counterweights, thus negating the cheap initial cost of the crank.
I know a bit old, however, im curious on the original question. Im thinking of building a stroked 5.3 or my original LS1 with intendion of boost. I was playing with come combustion and CI calculators and found some information pretty interesting. With an LS1s rod length and a 4" stroked crank, with some -3cc dished pistons, the compression ration hoveres around stock 10:1 with some vsriances by bore or cyclinder heads. Mine was with 317 heads in my calculations but i found that interesting.
Trying to locate a 5.3 block to get honed to ls1 bores, and then stick a 4" crank, summit turbo cam, and 317 heads.
Trying to locate a 5.3 block to get honed to ls1 bores, and then stick a 4" crank, summit turbo cam, and 317 heads.
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Joined: Jan 2008
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From: Ohio, Georgia, Nevada, Texas
I know a bit old, however, im curious on the original question. Im thinking of building a stroked 5.3 or my original LS1 with intendion of boost. I was playing with come combustion and CI calculators and found some information pretty interesting. With an LS1s rod length and a 4" stroked crank, with some -3cc dished pistons, the compression ration hoveres around stock 10:1 with some vsriances by bore or cyclinder heads. Mine was with 317 heads in my calculations but i found that interesting.
Trying to locate a 5.3 block to get honed to ls1 bores, and then stick a 4" crank, summit turbo cam, and 317 heads.
Trying to locate a 5.3 block to get honed to ls1 bores, and then stick a 4" crank, summit turbo cam, and 317 heads.
Again you cannot put stock rods and and stock pistons onto a 4" stroke crank. Stock rods are 6.098 with stock piston compression height at 1.34 and a stock stroke crank is 3.622.
Deck height of an LS is 9.25 so if you take have the stroke of the stock crank which is 3.622 and divide that by 2 you get 1.811. Now add that to the stock length connecting road which is 6.098 and you get 7.909. Now finally add the compression height of the stock piston which is 1.34 and what do you get folks!
9.249"
ding ding ding ding!
Deck height of an LS is 9.25 so if you take have the stroke of the stock crank which is 3.622 and divide that by 2 you get 1.811. Now add that to the stock length connecting road which is 6.098 and you get 7.909. Now finally add the compression height of the stock piston which is 1.34 and what do you get folks!
9.249"
ding ding ding ding!
I get that id have to change out rods and pistons, as id like to gap the rings while its apart anyway. I just found it interesting in the calculations using that same rod length from an ls1 in a 4" stroke. Besides, if i went out of my way for a forged crank, id have forged slugs and at least some Hbeam rods in there to give it a fighting chance.
Im all over the place but im curious about this as well.
So im wondering if i went with this stroker kit, i can do this either with the 5.7 I have OR find a 5.3l and bore it to 3.903 and essentiually have a 383 out of either engines WITH the Summit Racing® Pro LS 5.7L Rotating Assemblies SUM-R24409035?
Reason im considering this one is that with the 5cc domed pistons in this kit, it will keep my CC roughly at 9.9:1 with the 72cc 317 heads, and have the added benefit of not needing as much boost at lower rpm, and taking advantage of the strokers torque.
What do you think using the summit pro stage 2 turbo cam (226/230/ 0.600/0.575. /113 lsa) that i already have on standby with this kit?
So im wondering if i went with this stroker kit, i can do this either with the 5.7 I have OR find a 5.3l and bore it to 3.903 and essentiually have a 383 out of either engines WITH the Summit Racing® Pro LS 5.7L Rotating Assemblies SUM-R24409035?
Reason im considering this one is that with the 5cc domed pistons in this kit, it will keep my CC roughly at 9.9:1 with the 72cc 317 heads, and have the added benefit of not needing as much boost at lower rpm, and taking advantage of the strokers torque.
What do you think using the summit pro stage 2 turbo cam (226/230/ 0.600/0.575. /113 lsa) that i already have on standby with this kit?
LS1Tech Sponsor
Joined: Jan 2008
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From: Ohio, Georgia, Nevada, Texas
JoshuaGrooms83,
We thought you had a solid plan in the other thread using a 5.3 or 6.0 and just cleaning up the bores. We see that being the best route for your 1,000 hp target. We can see the temptation of building a stroker for boost. Yes, it can be done and you would have more low-end torque with a stroker.
If you're worried about blowing the tires off down low there's a solution. You could get an electronic boost controller or engine management system. Then bring the boost in gradually. You don't have to run 15 PSI right from the get-go.
If you're like the majority of us enough is never enough. First, it will be 10 PSI, then 15, 20, etc. The problem with a hogged out 5.3 or the LS1 is you're not going to have thick cylinder walls. When you start throwing moon boost to it they're not going to be as forgiving.
You'd be better off sticking with a stock bore and stroke iron 5.3 or 6.0 than going the stroker route. Put a good forged rotating assembly in it with better head and main fasteners. Throw the boost to it and get a good controller or management system to control the boost curve. This gives you something to build on as the build progresses.
Any of our Pro LS rotating kits and components are up to the task for whichever path you choose. The Pro LS stage 2 turbo cam is a great choice for this build and goals.
We feel in the end you'd be much happier going this route than the stroker route. You could build it whichever way you please but looking down the road we'd hold off on a stroker for this build.
We thought you had a solid plan in the other thread using a 5.3 or 6.0 and just cleaning up the bores. We see that being the best route for your 1,000 hp target. We can see the temptation of building a stroker for boost. Yes, it can be done and you would have more low-end torque with a stroker.
If you're worried about blowing the tires off down low there's a solution. You could get an electronic boost controller or engine management system. Then bring the boost in gradually. You don't have to run 15 PSI right from the get-go.
If you're like the majority of us enough is never enough. First, it will be 10 PSI, then 15, 20, etc. The problem with a hogged out 5.3 or the LS1 is you're not going to have thick cylinder walls. When you start throwing moon boost to it they're not going to be as forgiving.
You'd be better off sticking with a stock bore and stroke iron 5.3 or 6.0 than going the stroker route. Put a good forged rotating assembly in it with better head and main fasteners. Throw the boost to it and get a good controller or management system to control the boost curve. This gives you something to build on as the build progresses.
Any of our Pro LS rotating kits and components are up to the task for whichever path you choose. The Pro LS stage 2 turbo cam is a great choice for this build and goals.
We feel in the end you'd be much happier going this route than the stroker route. You could build it whichever way you please but looking down the road we'd hold off on a stroker for this build.
ok, I was just trying to see all my options. I really appreciate all the help! I was trying to keep the threads in their respective categories and topics, hence being in two different areas lol.
It would have been too easy for you to tell me to go ahead with the stroker kit and spend more money, but this demonstrates how much you guys actually care about your customers, even if it might costs a sale. I really appreciate your customer service and guidance. Its really easy to get carried away with window shopping when you are planning a project LOL
It would have been too easy for you to tell me to go ahead with the stroker kit and spend more money, but this demonstrates how much you guys actually care about your customers, even if it might costs a sale. I really appreciate your customer service and guidance. Its really easy to get carried away with window shopping when you are planning a project LOL
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Joined: Jan 2008
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From: Ohio, Georgia, Nevada, Texas
No problem JoshuaGrooms83. We appreciate you keeping the topics in two different threads. We just wanted to tie the two together for the community. Certainly, we care about our customers, and we want them to be happy with their purchase. Good luck with your project.
I built a 383 and turbo'd it like 15 years ago and the motor is still running to this day. That said, if I was doing it over again, I would have saved the coin and put it towards other parts.
