My Flat Tappet Cam Wiped Out So I Decided To Go Roller

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PlayingWithTBI

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According to the EBL Utility, with the flow matched 17084304 injectors I have, at 30 PSI it'll support 425 HP @0.45 BSFC, @85% DC. I'll probably have to go with a VRPR too. More stuff to play with :biggrin:
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L31MaxExpress

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VRPR? What is that?
By vacuum referencing the fuel pressure regulator you can reduce fuel flow for a smooth idle and when you go WOT the pressure and flow increases.

Unlike port fuel injected engines that use a vacuum referenced regulator to maintain a constant pressure differential across the injectors; using one on a TBI reduces the flow with vacuum.
 

PlayingWithTBI

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Ok thank you guys. I've never heard of it before.
Yeah, when I was playing with my 350, I had a 28 PSI spring on my 61Lb/Hr injectors. With the Lunati flat tappet cam running 208/213°, 466/484" (with 1.6 rockers), the EBL was trying to shut off the injectors completely at idle. That's when I went to 20 PSI and jacked up my VE tables to over 90% at higher MAP and RPMs. With 18PSI, I was running ~106% Duty Cycle @5300RPM, WOT. That meant the injectors were open all the time. The VRPR would have helped with the 28LB at 750 RPM. Now, going with more volume in the 383 and bigger cam, I may or may not need it, just thinking out loud. ;)
 

PlayingWithTBI

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Hot Rod Magazine tested the XR282 in a HT383 back in 2002ish. Here is what it made power wise with the Vortec heads on the ~9:1 HT383. Knowing they made 426 ft/lbs @ 2.500 I think your ~2,500 converter will probably be just fine. It will likely stall even higher behind the 383.

Peak HP: 455.3 @ 5,600
Peak Torque: 493.0 @ 4,200
Average HP 2,500-4,800: 327.4

Average Torque 2,500-4,800: 467.7
Average HP 4,000-5,700: 427.4
Average Torque 4,000-5,700: 465.3
Torque at 2,500: 426.3
I was thinking about this, do you remember if they were running 1.5 or 1.6 rockers in this test?
 

heskahoka

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Here is the whole article from March 2002:
 

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PlayingWithTBI

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Looks like 1.6:1. Here is the rocker spec from the article.
Thanks but, that looks like a different article. The cam coming with this short block is 230/236 @0.050", .510/.520" with 1.5 rockers. IDK if it's a Comp Cams or not but, I found the same specs it here.


Blue Print advertises it with 1.6 rockers, .544/.555"

 
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