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Old 11-14-2018, 01:49 AM   #51
72K5CSTDarkOlive
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Re: 427 SBC & 4L80e build

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Originally Posted by Chevyrestorerman View Post
Any idea of what the numbers would of been with the Sniper EFI ?
I'm not really sure what the difference would have been. I'm guessing at WOT there wouldn't be much of a difference.

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Originally Posted by TexasT View Post
I am JELLY! This is an aweso build all that is missing is ME! haha

Either way keep up the great work as it is going real well.
A suggestion or two. and you will have to fool with it(AKA:tune) is the 40* timing seems like a lot but different engines like different amounts. I would get a vac advance on there to help with mileage. and would try some lighter springs to get the mech in sooner. again this is tuning so it takes some time and effort to get it "ALL" out.

Might try some different fuel pressure settings(UP and Down). Just have to monitor the knock and stay out of it. Keep it fat(RICH) and you should be fine. and sneak up in leaning it out for power.

Looking forward to you getting it on the street. Great work.
Thank you! My engine builder said it was actually 38 degrees not 40. That was an error in the input field on the dyno sheet. There is definitely room for improvement for more HP & TQ. At peak HP the BSFC was at .518 which is on the high side of running rich. Th BSFC should be at around .430. We're thinking we could have gotten an additional 30-50 HP and TQ had been leaned out. Eventually, I will get a chassis dyno done and see what I'm getting at the wheels.
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Old 11-14-2018, 02:15 AM   #52
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Re: 427 SBC & 4L80e build

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Originally Posted by Chevyrestorerman View Post
How is that engine performing with the EFI, I am wanting to install a EFI sniper on my big block in my 72 blazer.

Sorry for the late response. Been working out a lot of kinks and sorting through some issues so now I finally have some data to report back on.

I kept going into Vapor Lock and was chasing the source for some time. On first startup the engine would run for about 20-30 minutes and stall. I would have to wait several minutes and it would then fire back up but stall again in just a few minutes. The tank is vented properly so I knew that wasn't the cause. I took the gas cap off and drove it to eliminate the possibility and it still did it.

I then threw a fuel pressure gauge on to see if I am losing fuel pressure at the fuel in right at the sniper's inlet port. I drove it until it stalled and had my friend try starting it while I checked to see what the gauge was reading and sure enough I had zero fuel pressure. I can still hear the fuel pump working so I knew it wasn't a bad pump.

I figured it had something to do with temperature and the gas was at the point of boiling so I tried re-routing my fuel lines and still no luck. I had them running up the transmission tunnel and made sure they were not resting on the heads or intake and even wrapped them with DEI's heat shield wrap and still would stall.

My engine temperature was only getting to about 170 before it would stall. The problem was my underhood temps was just cooking everything. I mean it was so hot under the hood I couldn't even touch my inner fenders. It was that BAD.

I removed the stainless steel headers and had them Cerakoted to help reduce radiant heat. I also ditched that clutch fan and put in a set of dual SPAL electric fans. With the Sniper I can control when the fans kick on and off. I set them to come on at 185 and to turn back off at 165.. The coolant temps needs to be above 160 for the Sniper to go into close loop and learn mode.

So after I got the headers back and the fans installed I started it up and drove for 200 miles without it ever stalling. I've since put on about 600 miles and have not had any stalling issues so I think it's safe to say my under hood temps was the problem with it going into vapor lock.

The Sniper is great! I'm really glad I went with the EFI because I was kind of hesitant at first. I have the AFR set at 14.2 at idle, 13.8 at cruise and 12.5 at WOT. My gas mileage is about 7.5 depending on how heavy my foot is.

I keep the RPM idle at 950 but I think that might be a little too high. They say with larger cams to set the rpm idle a little higher than the recommended 650-800 with stock/mild cam. The reason I feel like it's set to high is when it gets up to temp or after a long drive it will sometimes climb to 1100 in park and has dieseld on me a couple of times. Still need to continue testing different settings and such.

Overall, I'm happy with it and it's been a blast to drive. The 4l80e is great too. It's so smooth at 80 mph on the highway. The TCI controller let's you configure things such as shift firmness and aggression, when tq converter locks up, etc... I even added the optional switch for performance mode. This makes it hold each gear a little longer.
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Old 06-09-2019, 08:49 AM   #53
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Re: 427 SBC & 4L80e build

Mike...should have gotten over here sooner...but finally read through the engine build thread. So impressive. A lot of hard work, time, thought and money invested...and what a result. Congrats on an outstanding job. Love to see more pics with everything settled.
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Old 06-09-2019, 02:00 PM   #54
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Re: 427 SBC & 4L80e build

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Mike...should have gotten over here sooner...but finally read through the engine build thread. So impressive. A lot of hard work, time, thought and money invested...and what a result. Congrats on an outstanding job. Love to see more pics with everything settled.
Thank you Brad. This is officially the project that never ends I actually pulled the motor again and will be trading it back to my engine builder for a hopped up LQ9 with not as much valve lift. Something in the low to mid 500's for HP & TQ.

The reason I'm swapping is, first of all the 427 sbc is bad*** motor but it was just not practical for what I really wanted. I was constantly having to adjust the lash just about anytime I really stood on the pedal and I want something that I can take on long distance trips without any worries.
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Old 06-09-2019, 02:47 PM   #55
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Re: 427 SBC & 4L80e build

There is no cure for this illness.
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Old 06-09-2019, 04:03 PM   #56
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Re: 427 SBC & 4L80e build

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There is no cure for this illness.
I shouldn't be too hard on myself. I've learned so much over the last 4-5 years and you cant put a price on that. I literally had no idea what I was doing or any kind of guidance when I first started the resto. If I ever do another build I'll know how to plan accordingly and to do things right and in the right order.
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Old 06-09-2019, 05:01 PM   #57
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Re: 427 SBC & 4L80e build

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Originally Posted by 72K5CSTDarkOlive View Post
I shouldn't be too hard on myself. I've learned so much over the last 4-5 years and you cant put a price on that. I literally had no idea what I was doing or any kind of guidance when I first started the resto. If I ever do another build I'll know how to plan accordingly and to do things right and in the right order.
Completely agree. With regard to these projects, I value what is learned as much as what's accomplished. The experience itself is rewarding and the relationships made are priceless. My friends who play golf can't get their greens fees back. You've enjoyed your "hobby" and at the end of the day have an appreciable asset. It's a win/win.

...but I gotta be honest, I still worry about the torque on our ball joints.
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