370 build advice or thoughts welcome!
09-09-2006 | 05:21 PM
#31
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wll right now imdecding weather or not to go forged crank but it will take some extra time to get the money for that. as of now im rinning 42# svo injectors which flow about 50 psi at our prssure. so im sure those will need to be upgraded , and i have whatever magnacharger uses for 04 + fuel pumps. so what elese in the fuel delivery would i need? will i really have that high of fylinder pressure the i will need 1/2 head studs? maybe i will wait on the n20 for a while because i can live without it for now. right now 9.5 to 1 compression is going to be the target. i dont plan on running more than 12 psi for daily driving, i do plan on having it dyno tuned once everything gets put together though. i plan on having a tune for DD and a tune for high psi at the track.
09-09-2006 | 07:36 PM
#34
Originally Posted by vanillagorilla
I think I should elaborate a little further on what I said earlier, because I've had a few PM's regarding it.
This is all theory and I've never seen or heard of it being done, but it works on paper.
You take a 6.0L block with a standard or 0.030 over bore (9.240" deck height). Stock stroke crank (3.622") and 4.8L rods (6.275"). From there you use and off the shelf 402 or 408 stroker piston and you deck the block accordingly. JE and Wesico offer pistons in dished, flat top or domed with a compression height of 1.115"
Deck Height=9.240"
Rod Length=6.275"
Stroke/2=1.811"
Comp. Height=1.115"
9.240-6.275-1.811-1.150=.039"
So to the piston would be 0.039" in the hole, and you could deck the block accordingly to acheive your desired CR.
The advantages of a longer rod are numerous. Longer dwell at TDC and BDC, which creates more cylinder pressure which equals more power. Slower piston speeds which allows greater rpm capability, and reduces the stress on rod bolts. It decreases wear and tear and increases reliability. Also it decreases side loading on the piston due to a reduces rod angle. You get the idea...
Again, this is all theory with a budget in mind.
This is all theory and I've never seen or heard of it being done, but it works on paper.
You take a 6.0L block with a standard or 0.030 over bore (9.240" deck height). Stock stroke crank (3.622") and 4.8L rods (6.275"). From there you use and off the shelf 402 or 408 stroker piston and you deck the block accordingly. JE and Wesico offer pistons in dished, flat top or domed with a compression height of 1.115"
Deck Height=9.240"
Rod Length=6.275"
Stroke/2=1.811"
Comp. Height=1.115"
9.240-6.275-1.811-1.150=.039"
So to the piston would be 0.039" in the hole, and you could deck the block accordingly to acheive your desired CR.
The advantages of a longer rod are numerous. Longer dwell at TDC and BDC, which creates more cylinder pressure which equals more power. Slower piston speeds which allows greater rpm capability, and reduces the stress on rod bolts. It decreases wear and tear and increases reliability. Also it decreases side loading on the piston due to a reduces rod angle. You get the idea...
Again, this is all theory with a budget in mind.
I like this idea and I'm going to check into it some more. I have plans for a 6L in the near future, and I think this would work well for a low buck torquer.
09-09-2006 | 07:51 PM
#35
"12psi for daily driving" should not be how you look at building a motor if you plan on 15-17psi with spray on the strip. Even if you forego the Nitrous option 17psi is getting close to the limits for typical street power head gasket sealing options out there. With a centrifugal blower your max boost is at redline. Bang it off the rev limiter a couple of times at that boost and you risk pushing coolant... especially if detonation occurs. I have seen it too many times at 18+ psi with and w/o spray.. iron blocks, aluminum blocks, GM heads, AFR heads... it doesn't matter. There is only so much 4 head studs per cylinder can hold down. Standard size ARP head studs and MLS head gaskets with a max of 18psi is about as far as I would go... as there is some wiggle room in there for a multitude of possibilities where something can go wrong.
IMO with the probability of running 17psi... I would look into a custom fuel system. The 04+ Maggie pump setup will not flow even close to what your needs will be. I would look at, as one possible suggestion, an inline fuel pump that can flow 350+lph. Bosch has a couple of different models that flow near or over that but you need serious volume with that kind of boost. Goal is to keep the fuel pressure at a minimum of 58psi. Although some might disagree with me I would boost reference the fuel pressure. It can be more diffucult to tune but in the end its worth it. I would also run a return style setup with the fuel pressure regulator at or right near the rails. 60lb fuel injectors are pretty much a foregone conclusion at this point.
1/2" head studs are even more insurance. Are they necessary at your boost levels? No.
I agree with you that 2 tunes for 2 different performance levels is the safest way to go. Also may want to think about fuel quality as it is available to you. 91 Octane at 17psi, ESPECIALLY at your goal of 9.5:1 CR, will not cut it. You are looking at race gas or perhaps pump gas with an effective fuel additive like Torco. I don't know if you have Methanol injection but if you decide against Nitrous then Meth would be an excellant air/fuel charge cooling option. You could also use a 25shot of Nitrous as intended for air/fuel cooling. Don't forget with forced induction your shot of nitrous can have almost a doubling effect of its intended power increase. I have seen a 75 shot produce 125 extra rear wheel with a 408/F1R setup as one example... torque being equally impressive.
Hopefully your tuner also offers drivability (including WOT to redline through 3rd gear) street tuning on top of the dyno tuning.
May also want to think about a 4L80E as well... transfer case... diff... it never ends. A 65E will not hold up for very long with your power expectations. My truck is a daily driver too... and although my power levels will not reach yours for some time to come... I can't afford the down time and will probably look at an 80e... something that needs only a "freshening" every 25-30k miles of spirited daily driver use.
I am not trying to shy you away from your original intentions... just sharing with you my experience, what I would do, and what I plan on doing. Maybe others have had better experiences... maybe some have had worse.
Bill
IMO with the probability of running 17psi... I would look into a custom fuel system. The 04+ Maggie pump setup will not flow even close to what your needs will be. I would look at, as one possible suggestion, an inline fuel pump that can flow 350+lph. Bosch has a couple of different models that flow near or over that but you need serious volume with that kind of boost. Goal is to keep the fuel pressure at a minimum of 58psi. Although some might disagree with me I would boost reference the fuel pressure. It can be more diffucult to tune but in the end its worth it. I would also run a return style setup with the fuel pressure regulator at or right near the rails. 60lb fuel injectors are pretty much a foregone conclusion at this point.
1/2" head studs are even more insurance. Are they necessary at your boost levels? No.
I agree with you that 2 tunes for 2 different performance levels is the safest way to go. Also may want to think about fuel quality as it is available to you. 91 Octane at 17psi, ESPECIALLY at your goal of 9.5:1 CR, will not cut it. You are looking at race gas or perhaps pump gas with an effective fuel additive like Torco. I don't know if you have Methanol injection but if you decide against Nitrous then Meth would be an excellant air/fuel charge cooling option. You could also use a 25shot of Nitrous as intended for air/fuel cooling. Don't forget with forced induction your shot of nitrous can have almost a doubling effect of its intended power increase. I have seen a 75 shot produce 125 extra rear wheel with a 408/F1R setup as one example... torque being equally impressive.
Hopefully your tuner also offers drivability (including WOT to redline through 3rd gear) street tuning on top of the dyno tuning.
May also want to think about a 4L80E as well... transfer case... diff... it never ends. A 65E will not hold up for very long with your power expectations. My truck is a daily driver too... and although my power levels will not reach yours for some time to come... I can't afford the down time and will probably look at an 80e... something that needs only a "freshening" every 25-30k miles of spirited daily driver use.
I am not trying to shy you away from your original intentions... just sharing with you my experience, what I would do, and what I plan on doing. Maybe others have had better experiences... maybe some have had worse.
Bill
09-09-2006 | 10:39 PM
#36
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well that answers most of my questions, i may just not run boost to the # id like. im pretty sure the t trim is capable of making some big #'s but im not trying to spend an arm and a leg. i will consider new fuel injectors and a new fuel pump , id like to keep the returnless system but i may have no choice. so right now im going to start the bottom end and go from there.
what all is invloved with changing from returnless to a return system? i may do a new intake manifold but i know most of them require a new water pump also. this way i can get something like a fast and get the fast fuel rails as well. im just trying to get all the crap i need to make this work out!
what all is invloved with changing from returnless to a return system? i may do a new intake manifold but i know most of them require a new water pump also. this way i can get something like a fast and get the fast fuel rails as well. im just trying to get all the crap i need to make this work out!
09-10-2006 | 12:01 AM
#39
On a 370 a T-Trim will probably get you to your boost goals. I know on a C5 with the jack shaft crap that Vortech supplies, at least on a 7L struggling to 13psi, the T-Trim is gasping. I also remember the same motor with the 6-rib accessory drive absolutely powdered the plastic power steering pulley. The trucks, at least mine, has a steel p/s pulley.
Mototron is the choice for the 60lb injectors. I guess Siemens actually makes them. I have seen 700rwhp/800rwtq on the FMS 42's (actually equate to about 50lb at 58psi)... but the duty cyle is terrible... real bad at max torque... uncontrollable a/f ratio. The best I have seen on the 60's is 900rwhp (boost referenced)... as in 72+ psi of fuel pressure at max RPM. I have used the RC Engineering 75lb injectors but that was awhile back before the 60lb Mototrons became mainstream. I never had problems with the RC Engineering injectors but some complained of the spray pattern. When buying injectors I recommend paying for flow match... otherwise have them flow matched locally. If you want to get **** put the rich injectors in #7 and #8 hole.
As far as factory fuel on the 04's... the fuel pressure regulators are in the tanks. Beyond this I speculate because the majority of my experience is with 97-03E C5's and GENIII motor F-Body's. This is what I have done on C5's... and probably wouldn't be much different with exception to minor harware alterations to accomodate getting a quantity of fuel from a truck tank to fuel rails and then return to the tank. There are clean ways of doing this... through the factory tank bulkhead... and there are custom ways (sometimes easier and cheaper) of supplying and returning unused fuel. It really depends on what is available to you as far as welding skills and/or understanding how to run a sump feed from an existing factory tank. Bottom line is you need to run at a minimum of a #6 AN hose from the tank through, as a suggestion I mentioned earlier, an inline high volume pump, through the rails... the pressure is then regulated by tying together the other sides of the rails and then into an aftermarket fuel pressure regulator. I have used CAS and Aeromotive... both very effective. The return hose is then routed from the fuel pressure regulator back to the tank. Easeist way is to create a bulkhead fitting on the tank to allow return to drain in tank. Sorry if I am vague but there are lots of ways of doing this. Maybe PM parish and ask him how he is supplying fuel. Obviously you are not at his expected power levels but at a certain point building a fuel system for a 700+ crank horsepower motor is not a whole lot different than a 1500+ crank motor... just the size of the lines and pumps
You can always try returnless first... get back to us and let us know how far you get. I suspect somewhere around 600-650rwhp. Key thing is to monitor fuel pressure at least during intial WOT's on the dyno to see if it drops. If it does... you'll know you have it the limit. FWIW, I am not at all a fan of any sort of fuel pressure drop. It must be stable or increase (if boost referenced).
You will also need to consider how you will keep the crank case evacuated at your boost levels... even at 12+ psi. Crank case pressure is detrimental to power and life of the motor.
Bill
Mototron is the choice for the 60lb injectors. I guess Siemens actually makes them. I have seen 700rwhp/800rwtq on the FMS 42's (actually equate to about 50lb at 58psi)... but the duty cyle is terrible... real bad at max torque... uncontrollable a/f ratio. The best I have seen on the 60's is 900rwhp (boost referenced)... as in 72+ psi of fuel pressure at max RPM. I have used the RC Engineering 75lb injectors but that was awhile back before the 60lb Mototrons became mainstream. I never had problems with the RC Engineering injectors but some complained of the spray pattern. When buying injectors I recommend paying for flow match... otherwise have them flow matched locally. If you want to get **** put the rich injectors in #7 and #8 hole.
As far as factory fuel on the 04's... the fuel pressure regulators are in the tanks. Beyond this I speculate because the majority of my experience is with 97-03E C5's and GENIII motor F-Body's. This is what I have done on C5's... and probably wouldn't be much different with exception to minor harware alterations to accomodate getting a quantity of fuel from a truck tank to fuel rails and then return to the tank. There are clean ways of doing this... through the factory tank bulkhead... and there are custom ways (sometimes easier and cheaper) of supplying and returning unused fuel. It really depends on what is available to you as far as welding skills and/or understanding how to run a sump feed from an existing factory tank. Bottom line is you need to run at a minimum of a #6 AN hose from the tank through, as a suggestion I mentioned earlier, an inline high volume pump, through the rails... the pressure is then regulated by tying together the other sides of the rails and then into an aftermarket fuel pressure regulator. I have used CAS and Aeromotive... both very effective. The return hose is then routed from the fuel pressure regulator back to the tank. Easeist way is to create a bulkhead fitting on the tank to allow return to drain in tank. Sorry if I am vague but there are lots of ways of doing this. Maybe PM parish and ask him how he is supplying fuel. Obviously you are not at his expected power levels but at a certain point building a fuel system for a 700+ crank horsepower motor is not a whole lot different than a 1500+ crank motor... just the size of the lines and pumps
You can always try returnless first... get back to us and let us know how far you get. I suspect somewhere around 600-650rwhp. Key thing is to monitor fuel pressure at least during intial WOT's on the dyno to see if it drops. If it does... you'll know you have it the limit. FWIW, I am not at all a fan of any sort of fuel pressure drop. It must be stable or increase (if boost referenced).You will also need to consider how you will keep the crank case evacuated at your boost levels... even at 12+ psi. Crank case pressure is detrimental to power and life of the motor.
Bill
Awesome info, I am paying very close attention also.