Build Advice
09-11-2017, 05:33 PM
#11
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Icdedppls non intercooled 1071 making around 8 lbs of boost on his 540s, has around 135-140* intake temps iirc. It didnt seem to change much if any going from 6 to 8 psi.
My intercooled B&M 420s, are in the 105-115 range with 8-9psi. My boat takes a while to plane off. I can see the intake temps climb to 140-150, then as the boat lays over, and begins moving water thru the intercooler, the temp drops 30 degrees very quickly. I was always skeptical about intercoolers, as I had never found anyone doing any temp readings in the intake manifold. After installing them, I can say that they do in fact do their job.
I would love to see some intake temps with a 177 or 250 blower setup. It be interesting to compare.
My intercooled B&M 420s, are in the 105-115 range with 8-9psi. My boat takes a while to plane off. I can see the intake temps climb to 140-150, then as the boat lays over, and begins moving water thru the intercooler, the temp drops 30 degrees very quickly. I was always skeptical about intercoolers, as I had never found anyone doing any temp readings in the intake manifold. After installing them, I can say that they do in fact do their job.
I would love to see some intake temps with a 177 or 250 blower setup. It be interesting to compare.
09-11-2017, 05:50 PM
#12
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iTrader: (3)
Icdedppls non intercooled 1071 making around 8 lbs of boost on his 540s, has around 135-140* intake temps iirc. It didnt seem to change much if any going from 6 to 8 psi.
My intercooled B&M 420s, are in the 105-115 range with 8-9psi. My boat takes a while to plane off. I can see the intake temps climb to 140-150, then as the boat lays over, and begins moving water thru the intercooler, the temp drops 30 degrees very quickly. I was always skeptical about intercoolers, as I had never found anyone doing any temp readings in the intake manifold. After installing them, I can say that they do in fact do their job.
I would love to see some intake temps with a 177 or 250 blower setup. It be interesting to compare.
My intercooled B&M 420s, are in the 105-115 range with 8-9psi. My boat takes a while to plane off. I can see the intake temps climb to 140-150, then as the boat lays over, and begins moving water thru the intercooler, the temp drops 30 degrees very quickly. I was always skeptical about intercoolers, as I had never found anyone doing any temp readings in the intake manifold. After installing them, I can say that they do in fact do their job.
I would love to see some intake temps with a 177 or 250 blower setup. It be interesting to compare.
09-11-2017, 06:58 PM
#13
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09-11-2017, 08:35 PM
#14
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Thread Starter
i may know a guy that knows a guy that is looking:P they got the anodizing?
my 575 is bone stock as they come, maybe ill try and tinker with some readings. im guessing Mefi 3 only has a IAT in the throttle body in this application
what coolers are you using Mild?
my 575 is bone stock as they come, maybe ill try and tinker with some readings. im guessing Mefi 3 only has a IAT in the throttle body in this application
what coolers are you using Mild?
12-19-2017, 09:33 AM
#16
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Thread Starter
been doing some more digging with different blowers, is a 10-71 to large for a 502? would a "standard" -71 intake manifold work on a 10-71? with the 10-71 being longer then a 6 or a 8, i would need to run a crab style cap on the distributor? or do i need to replace the whole unit?
12-19-2017, 10:59 AM
#17
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been doing some more digging with different blowers, is a 10-71 to large for a 502? would a "standard" -71 intake manifold work on a 10-71? with the 10-71 being longer then a 6 or a 8, i would need to run a crab style cap on the distributor? or do i need to replace the whole unit?
I have a stripped 871 with whipple chiller on my 575, I ran with stock cam and heads for years with 9psi boost and never had an issue, although on teardown it had a cracked exhaust valve. I would not be afraid to run the 7.5 stock (JE) pistons, even with a 671 which is a 155CI larger than your 256. The lower end has (Manley?) crank and Manley H beam rods so you will be fine there.
12-19-2017, 11:16 AM
#18
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Im about 4 weeks away from the boating season up here from being over and i think its time to do a little maintenance and maybe go a little faster. i have a 03 575sci, 15Xhours on the clock. been on here doing a lot of reading so i know enough to know i know nothing, or just enough to spend a lot of money and go no faster haha. so far my plan is floating around the bottom end not needing anything, all leak down numbers where pretty good at the start of the season and its ran all good for the year.
The heads, even with good numbers and what looks like maybe some good velocity, are they going to choke the motor out? i dont see my self wanting it to spin higher then 5800 (for now) will the 115 chamber vs the 118 chambers on the stock heads make any difference at all?
what head gaskets? i dont want to pull the motor and do a full tear down if i can avoid it and from what i recall MLS gaskets prefer a fresh surface.
any and all feed back is welcome please!
- heads. im leaning on the Brodix BB-R heads - 2061013 -, the flow numbers look pretty darn good for a "smaller" head, and flow pretty close to a lot of the bigger heads into the .600 range, the 115cc chamber should help with bringing up compression a wee-bit . they also dont raise the exhaust port so that keeps added work down to a minimum.
- cam. seems like a very popular pick is the "741" or 525 cam and i was honestly going to go with that. if its not broken kinda deal. especially for a not super extreme build
- Intake. going to retire the 256 and go 8-71 and aim for 6psi
The heads, even with good numbers and what looks like maybe some good velocity, are they going to choke the motor out? i dont see my self wanting it to spin higher then 5800 (for now) will the 115 chamber vs the 118 chambers on the stock heads make any difference at all?
what head gaskets? i dont want to pull the motor and do a full tear down if i can avoid it and from what i recall MLS gaskets prefer a fresh surface.
any and all feed back is welcome please!
12-19-2017, 01:43 PM
#19
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Thread Starter
I wanna avoid a full tear down as much as i can, i have this very bad habit of wanting to do more then is needed, like a 540 and a bottom end to take on 10+psi if I'm already in their why not right?, that being said if i have to go bottom end i will but I'm going to try and avoid it as much as i can, with 15Xh on the clock and it being a Havasu boat I'm hoping most of the clock time is from sitting on the beach. I did get a set of AFR 305's, going to go with Eddie young's EFI and some more of his recommended goodies. im just worried that a 10-71 will suck to much power at lower boost like 8psi vs a 8-71 and will be spinning to slow to be worth it. even if the 10 was at a 1:1 ration, on TBS site it show it around 10psi, with the bigger cam and heads thats probably 9 ish. that even in a 10-71 efficiency range?
12-19-2017, 02:58 PM
#20
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When you pull the heads you might find cylinders glazed due to wash-down and may need to tear it down. Changing the oil pump may also be a good idea as well as a larger capacity pan. If you are going to have it out, why not flip it over and at minumum inspect the bearings? I will be the devils advocate...if you go with eddies injection plate you could easily go 540. Anyway, the faster you spin the blower the more heat you will make, I would think their would be some added safety margin with a 10-71. I dont think the parasitic loss would be much more than a 871 especially at 10psi or less.
