I'm actually leaning that way, I've been all over the place with the engine, I'm starting to think about gas mileage, already got two pigs on gas 5.9l Jeep & 400 Bronco, starting to think about turbo/s 273 still doing research on which turbo/s to get for 500hp.
The Little Engine That Could
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I'm actually leaning that way, I've been all over the place with the engine, I'm starting to think about gas mileage, already got two pigs on gas 5.9l Jeep & 400 Bronco, starting to think about turbo/s 273 still doing research on which turbo/s to get for 500hp.
txstang84
Well-Known Member
If you're looking at twins, probably a couple of t3/t4 hybrids would work well for quick spool and move lots of air with the T4 impellers...I bet madart could help you out there
txstang84
Well-Known Member
There are tons of ways to do it...just gotta be smart about your parts choices. Unless you're looking for a race only all out screamer, you can save a few pennies running a journal bearing type turbo as opposed to a ball bearing. Ball bearing types spool quicker and arguable will last longer, but they're also a few hundred more per unit and you can't rebuild the cartridge...journal bearing types will still be more than sufficient for continued use and can be overhauled.
Don't skimp on the blowoff valve and wastegates...you go cheap on these and you can hurt your turbos and the engine.
Intercoolers could honestly go either way. As I've been researching my other project-4.6 4V in my '84 Mustang, I ran into a fella on a Mustang forum from PA that helped me out a lot...he said even the inexpensive CX Racing intercooler kits are pretty decent units up to about 600-700hp...after that you really have to plunk down the $ for a good one like Spearco or Treadstone.
Piping is gonna be based on your hp goal...3" will carry enough air to support a SB up to about 550rwhp...after that, you need to get the 3.5" or 4". Just buy a generic kit and TIG it up to how you need it. Same goes for exhaust. Check out Columbia River Mandrel Bending...they sell some good quality stuff at decent prices. I used a few of their 2.5" U bends to have my exhaust fabbed.
Induction-if you're going carbed, don't go cheap here either...a non-boost carb can make you pull your hair out trying to keep the metering good.
....that's about all I can think of for now. Going turbos isn't cheap if you do it the right way, but neither is dropping a big block into early A unless you're a very talented fabricator and/or have hookups.
Don't skimp on the blowoff valve and wastegates...you go cheap on these and you can hurt your turbos and the engine.
Intercoolers could honestly go either way. As I've been researching my other project-4.6 4V in my '84 Mustang, I ran into a fella on a Mustang forum from PA that helped me out a lot...he said even the inexpensive CX Racing intercooler kits are pretty decent units up to about 600-700hp...after that you really have to plunk down the $ for a good one like Spearco or Treadstone.
Piping is gonna be based on your hp goal...3" will carry enough air to support a SB up to about 550rwhp...after that, you need to get the 3.5" or 4". Just buy a generic kit and TIG it up to how you need it. Same goes for exhaust. Check out Columbia River Mandrel Bending...they sell some good quality stuff at decent prices. I used a few of their 2.5" U bends to have my exhaust fabbed.
Induction-if you're going carbed, don't go cheap here either...a non-boost carb can make you pull your hair out trying to keep the metering good.
....that's about all I can think of for now. Going turbos isn't cheap if you do it the right way, but neither is dropping a big block into early A unless you're a very talented fabricator and/or have hookups.
txstang84
Well-Known Member
The biggest difference between them is going to be in the heads...273 heads will require some careful work and prep to flow well...I've read a few places that have worked over the 80s 302 castings to do just that.
Hot Rod magazine did a build on a 318 with those heads and it made over 350fwhp N/A (yeah, yeah, I know...it's a magazine and their dyno is probably tweaked to sell copies, I get it). That being said, they did a lot of work to the heads and flowed over 200cfm @ .500 lift with 2.02/1.60 valves. I know you can't make that fit in a 273, but even with the smaller 1.78/1.60 valves or upgrade to 1.88 intakes, they'd probably do better than the older 920 castings and come with hardened seats from the factory. Did I mention that every 318 starting in '84 used them until the 5.2's came out? Here's the article:
http://www.hotrod.com/howto/113_0304_318_small_block_build/viewall.html
Now...that brings us to pistons...I couldn't readily find any forgings that would take that much abuse. I'm without doubt someone like Diamond could make whatever you want, but custom = $$...
...damn...maybe the 273 could turn into a 318/360?
Hot Rod magazine did a build on a 318 with those heads and it made over 350fwhp N/A (yeah, yeah, I know...it's a magazine and their dyno is probably tweaked to sell copies, I get it). That being said, they did a lot of work to the heads and flowed over 200cfm @ .500 lift with 2.02/1.60 valves. I know you can't make that fit in a 273, but even with the smaller 1.78/1.60 valves or upgrade to 1.88 intakes, they'd probably do better than the older 920 castings and come with hardened seats from the factory. Did I mention that every 318 starting in '84 used them until the 5.2's came out? Here's the article:
http://www.hotrod.com/howto/113_0304_318_small_block_build/viewall.html
Now...that brings us to pistons...I couldn't readily find any forgings that would take that much abuse. I'm without doubt someone like Diamond could make whatever you want, but custom = $$...
...damn...maybe the 273 could turn into a 318/360?
Txstang84, 1wild&crazyguy got a sticky on a port job with 318 head and stock valves and valve job that get over 200 cfms, I should just go with EQ and notch the bore, that's been the biggest head ache with a 273 build is deciding on valve size. I'm gonna go custom froged pistons there $$$ but $300 extra for piston over 318/340/360 is no big deal. I've decided on single turbo seems the best option, now I got to decide on on compression since doing the engine first and add the turbo latter 8:1 will allow more boost but 9:1 will make a better daily driver plus will get better mileage.
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