what will work better for crossfire?
http://www.jegs.com/p/Blueprint-Engi...97259/10002/-1
or
http://www.jegs.com/p/Chevrolet-Performance/Chevrolet-P
erformance-350ci-290HP-Engine-Package/755609/10002/-1
any help will be great. Need a new engine and would like to keep orig. intake. I am most concerned with the cams, Are they too big? I have ported the intake as much as I can .Evan have a spare incase for some reason I wanna go back
Last edited by frankinvett84; Feb 25, 2014 at 06:35 PM.
one more chance with brand new motor under it. I've read that the ecm doesn't "like"
too much cam but I know that it also depends on the heads. I'm just looking for the most info I can before getting a crate engine .
if you want to keep your factory wiring harness, just use a carbed intake and a 454 TBI with a baseplate adapter, you can keep the stock ECM too and it flows 670 CFM
although it still wont perform as good as an aftermarket EFI system, TPI, or even a well tuned carb
I like the convenience and options for future mods of a aluminum headed performance crate engine. my budget is between $3000-$4000. and that's with any replacement parts like flywheel t-conv. ect. I might run across while installing new engine
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if you want to keep your factory wiring harness, just use a carbed intake and a 454 TBI with a baseplate adapter, you can keep the stock ECM too and it flows 670 CFM
although it still wont perform as good as an aftermarket EFI system, TPI, or even a well tuned carb
A TPI won't perform any better than a ported intake, and barely better than an unported one.
The 454 TBI on a good single plane intake will easily out perform any stock TPI.
No way you'll get 375hp through a stock CFI intake. Even a ported one won't get you there (and neither will any stock TPI). A well ported CFI intake, feeding it what it wants, can get you 300 - 320 horse. The "blueprint" engine has way too much cam for a 350. It would work but idle rough and not pass emissions w/o some kind of tune/aftermarket ECM to control it. The 290 hp engine would work fine, and you'd probably end up with around 250 hp with your stock exhaust, accessories, etc.
and unlike crossfire, TPIs have a far larger aftermarket, respond better to mods, and instead of spending enormous amounts of time and effort porting a Crossfire intake, TPIs can easily be replaced with a converted LT1 intake which will easily flow more than any stock/near stock L98 will need
after owning both, the TPI cars are far easier to work on, cheaper to upgrade, more reliable, and produce better results and performance both when stock and modified
Last edited by Tom400CFI; Feb 26, 2014 at 05:08 PM.
Both stock (ok I had a catback 3.07 gear) his a 3.54 gear stock with that top aftermarket plate (cant recall the name.
Most times dead heat if that tells you anything other than they were both slow
right now. I wanted to buy a crate engine (leaning towards blueprint375hp) put it under my heavily ported intake with headman 1 5/8" headers stock pipes to gutted catto dynomax mufflers I also have airpump delete. My question is why "way too much cam" I don't care about gas mileage and don't want smooth idle also no need for emission testing. just wanna put a 300 to 375 hp engine under my ported cfi to see if I can make it do a 1/4 mile less than 13 sec..if not I have a decent engine I can put some other induction system on . For over a decade I ve been "Playing "with my crossfire I love it. I need to see what I can make it do on top of a decent engine. oh and would really like to keep low end torque . am I pushing reality?
Last edited by frankinvett84; Feb 26, 2014 at 07:05 PM.
If you don't care about mileage, idle, emissions, that cam would work. I ran a 224/234 cam under my CFI and it ran great...but that was in a 400.
Basically, your 350 with a ~230ish cam will change the shape of the toque curve, and change the tq peak RPM. This means that your air flow requirements will not be aligned with your fueling. You can band-aid it by changing injector size, pressure, etc. and make it go pretty good, but it's not ideal. I think 12's are possible. I went low 13's with mind on low compression, crappy stock heads, and poor exhaust.
Let's rephrase that. You could spent a ton of money replacing all the parts that make a TPI a TPI (>$1000), or you could simply spend a little time on a hobby and get some major gains for the price of a set of intake gaskets by porting the CFI intake.
Huh. I've owned both too. Opposite was true for me. CFI got better gas mileage too.
even the renegade manifold claims to provide 15-30HP gains at best, which has never been able to have been backed up by any dyno tests
as for spending over 1K upgrading a TPI intake, thats laughably false, i converted my 87 to a LT1 intake and it cost me a grand total of $53 including the intake itself and gaskets
^That's one.
My own '83 Trans Am which was a 305 CFI went 14.5/95. How many hp does it take to run 14.5/95 in a 3300 lb car? Takes about 230hp or so. When my car ran that, mods were:
*Edelbrock TES manifolds
*Advanced timing
*Fuel pressure
*BW T5 trans (CFI TA's never came w/a stick shift like the 'Vette did)
Notice that I didn't say "ported intake". I ran those numbers with a box-stock CFI intake...on a 305.
Next engine in that same car was a TBI Vortec 350 long block (peanut cam), stock unported intake, same exhaust...14.1x's/98. Know how many hp it takes to run 14.1x's/98 in a 3300 lb car? About 245 or so.
LT1 intakes are short, straight runner intakes, and hvae nothing to do with "TPI". You're talking about (or confusing) two different things.
Last edited by Tom400CFI; Feb 26, 2014 at 10:10 PM.













