lm7 turbo question
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lm7 turbo question ok, Im currently in the process of building a (somewhat) budgeted lm7 motor for an s10 im restoring. It will probably see anywhere from 5-10 pounds of boost.
my question is, will it hold up?
so far i have planned:
lm7 bottom end
lq9 heads
ls6 intake
ARP rod and head bolts
hardened push rods
Yella Terra Roller Rockers
SLP Heavy duty oil pump
SLP Double Roller timing chain
Texas Speed Custom Grind Cam
PRC Double Springs w/titanium Retainers
also for street use, which cam would you recommend? I want the turbo to spool up quick so its actually usable power
also, truck is 4l60e automatic, with 3.73 gears
my question is, will it hold up?
so far i have planned:
lm7 bottom end
lq9 heads
ls6 intake
ARP rod and head bolts
hardened push rods
Yella Terra Roller Rockers
SLP Heavy duty oil pump
SLP Double Roller timing chain
Texas Speed Custom Grind Cam
PRC Double Springs w/titanium Retainers
also for street use, which cam would you recommend? I want the turbo to spool up quick so its actually usable power
also, truck is 4l60e automatic, with 3.73 gears
I think the LM7 with 317s yields about 8.6:1
Stock LM7 is lower than 10:1 if I recall. If you want it to spool quickly, keep the comp up. With only 5-10lbs of boost, you shouldn't have to worry.
Stock LM7 is lower than 10:1 if I recall. If you want it to spool quickly, keep the comp up. With only 5-10lbs of boost, you shouldn't have to worry.
Id use the stock 5.3 heads. The LM7 has 9.5 compression. Dropping 317's on will drop the compression too much unless your going for big boost which you are not.
I just put together a stock longblock 5.3 (stock cam, valvesprings, everything) with a Master Power T70 .96 that runs really really good on 8 psi. It lays over at 5500 due to the stock cam but the boost comes in fast, has great response, and is great street setup.
What turbo are you planning?
I just put together a stock longblock 5.3 (stock cam, valvesprings, everything) with a Master Power T70 .96 that runs really really good on 8 psi. It lays over at 5500 due to the stock cam but the boost comes in fast, has great response, and is great street setup.
What turbo are you planning?
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Id use the stock 5.3 heads. The LM7 has 9.5 compression. Dropping 317's on will drop the compression too much unless your going for big boost which you are not.
I just put together a stock longblock 5.3 (stock cam, valvesprings, everything) with a Master Power T70 .96 that runs really really good on 8 psi. It lays over at 5500 due to the stock cam but the boost comes in fast, has great response, and is great street setup.
What turbo are you planning?
I just put together a stock longblock 5.3 (stock cam, valvesprings, everything) with a Master Power T70 .96 that runs really really good on 8 psi. It lays over at 5500 due to the stock cam but the boost comes in fast, has great response, and is great street setup.
What turbo are you planning?
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Let me know how that turbo works out for you. I contacted the sales rep about it asking if he has proof that it uses ceramic ball bearings, he said he couldn't take one apart without having to get it rebalanced. He did assure me that he has face-to-face contact with his supplier and that there is a very noticeable difference in shaft drag between the same size turbos in ball bearing vs sleeve bearing. He said the difference was audible as well (bearings make a unique noise).
Still, it is kinda strange behavior for a seller. If I was selling turbos and components I'd disassemble one of each product to show potential buyers that they are getting exactly what they pay for; especially if there was some doubt about their construction. I even mentioned to him that I bought a turbo once only to disassemble it and discover that it was sleeve bearing instead of ball bearing as advertised. There is no doubt that the oil requirements are different for ball bearings and I could have potentally ruined the turbo by putting a restrictor on it.
There is no doubt too that a single person who discovers that the seller is a liar can easily ruin the sellers reputation with just a couple posts and pictures on a forum.
Then again, maybe the seller is telling the truth, the turbo is awesome, and all of my fears are irrational
I'll be using one for my build if I hear enough good press, but right now it seems like an untested path. Don't let me dissuade you, I'm just pointing out concerns about an untested path
Still, it is kinda strange behavior for a seller. If I was selling turbos and components I'd disassemble one of each product to show potential buyers that they are getting exactly what they pay for; especially if there was some doubt about their construction. I even mentioned to him that I bought a turbo once only to disassemble it and discover that it was sleeve bearing instead of ball bearing as advertised. There is no doubt that the oil requirements are different for ball bearings and I could have potentally ruined the turbo by putting a restrictor on it.
There is no doubt too that a single person who discovers that the seller is a liar can easily ruin the sellers reputation with just a couple posts and pictures on a forum.
Then again, maybe the seller is telling the truth, the turbo is awesome, and all of my fears are irrational
I'll be using one for my build if I hear enough good press, but right now it seems like an untested path. Don't let me dissuade you, I'm just pointing out concerns about an untested path
ok, Im currently in the process of building a (somewhat) budgeted lm7 motor for an s10 im restoring. It will probably see anywhere from 5-10 pounds of boost.
my question is, will it hold up?
so far i have planned:
lm7 bottom end
lq9 heads
ls6 intake
ARP rod and head bolts
hardened push rods
Yella Terra Roller Rockers
SLP Heavy duty oil pump
SLP Double Roller timing chain
Texas Speed Custom Grind Cam
PRC Double Springs w/titanium Retainers
also for street use, which cam would you recommend? I want the turbo to spool up quick so its actually usable power
also, truck is 4l60e automatic, with 3.73 gears
my question is, will it hold up?
so far i have planned:
lm7 bottom end
lq9 heads
ls6 intake
ARP rod and head bolts
hardened push rods
Yella Terra Roller Rockers
SLP Heavy duty oil pump
SLP Double Roller timing chain
Texas Speed Custom Grind Cam
PRC Double Springs w/titanium Retainers
also for street use, which cam would you recommend? I want the turbo to spool up quick so its actually usable power
also, truck is 4l60e automatic, with 3.73 gears
Good fuel and a GOOD TUNE is what will keep it together!
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Let me know how that turbo works out for you. I contacted the sales rep about it asking if he has proof that it uses ceramic ball bearings, he said he couldn't take one apart without having to get it rebalanced. He did assure me that he has face-to-face contact with his supplier and that there is a very noticeable difference in shaft drag between the same size turbos in ball bearing vs sleeve bearing. He said the difference was audible as well (bearings make a unique noise).
Still, it is kinda strange behavior for a seller. If I was selling turbos and components I'd disassemble one of each product to show potential buyers that they are getting exactly what they pay for; especially if there was some doubt about their construction. I even mentioned to him that I bought a turbo once only to disassemble it and discover that it was sleeve bearing instead of ball bearing as advertised. There is no doubt that the oil requirements are different for ball bearings and I could have potentally ruined the turbo by putting a restrictor on it.
There is no doubt too that a single person who discovers that the seller is a liar can easily ruin the sellers reputation with just a couple posts and pictures on a forum.
Then again, maybe the seller is telling the truth, the turbo is awesome, and all of my fears are irrational
I'll be using one for my build if I hear enough good press, but right now it seems like an untested path. Don't let me dissuade you, I'm just pointing out concerns about an untested path
Still, it is kinda strange behavior for a seller. If I was selling turbos and components I'd disassemble one of each product to show potential buyers that they are getting exactly what they pay for; especially if there was some doubt about their construction. I even mentioned to him that I bought a turbo once only to disassemble it and discover that it was sleeve bearing instead of ball bearing as advertised. There is no doubt that the oil requirements are different for ball bearings and I could have potentally ruined the turbo by putting a restrictor on it.
There is no doubt too that a single person who discovers that the seller is a liar can easily ruin the sellers reputation with just a couple posts and pictures on a forum.
Then again, maybe the seller is telling the truth, the turbo is awesome, and all of my fears are irrational
I'll be using one for my build if I hear enough good press, but right now it seems like an untested path. Don't let me dissuade you, I'm just pointing out concerns about an untested path
call me a newb, but what were you talking about with ball bearings needing different oil setup
would the other things hurt me at all? i've already bought some things, so im just curious what i should keep
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well ill do my best to post some type of review on it when i get it installed...
call me a newb, but what were you talking about with ball bearings needing different oil setup
would the other things hurt me at all? i've already bought some things, so im just curious what i should keep
call me a newb, but what were you talking about with ball bearings needing different oil setup
would the other things hurt me at all? i've already bought some things, so im just curious what i should keep
The reason for this is that journal bearings need good oil pressure to float the shaft inside the bearings. Metal to metal contact between the bearings and the shaft is avoided in this way. Technically, the metal should never touch. In ball bearings, the oil only serves to cool and lubricate the ***** and races. The oil demands are less because you are not trying to float the shaft with oil pressure. Too much oil in a ball bearing turbo actually increases parasitic drag because the bearings would have to churn through oil.
If it has ball bearings you should be ok adding a restrictor (maybe ask on3performance what kind of feed it needs or if it has a built in restrictor), if it has journal bearings and you add a restrictor, it will probably fail.
Last edited by killernoodle; Jun 22, 2011 at 10:46 AM.
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Ball bearings generally need less oil than journal bearings. So I would be in the mindset that this is a ball bearing turbo and therefore I should install a restrictor onto the oil feed. This would have certainly caused damage because the journal bearings that are actually installed in the turbo would be starved of oil and fail.
If it has ball bearings you should be ok adding a restrictor (maybe ask on3performance what kind of feed it needs or if it has a built in restrictor), if it has journal bearings and you add a restrictor, it will probably fail.
If it has ball bearings you should be ok adding a restrictor (maybe ask on3performance what kind of feed it needs or if it has a built in restrictor), if it has journal bearings and you add a restrictor, it will probably fail.
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not a problem... maybe a while before i get the turbo, Im still trying to do the wiring harness... 4 hours and counting
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