Engine 347 Na Crate Engine Questions

[90silverstang]

Have a 347 NA engine that dynoed 445 hp at 6000 rpm with a carburetor set up when the engine was built by T & L engine a few years back. Compression 10:1. They used a carburetor set up because they did not have ECU w/ fuel injection set up at there shop. I ordered the engine with fuel injection set up which was a Edelbrock Performer RPM II upper and lower with 30 lb injectors and a ProM 75mm MAF calibrated for 30lb injectors. ProM also sent a "generic tuned chip" for this set up. So--- the engine was never dynoed an tuned with the fuel injection set up. The efi set up was just shipped along to me and I installed it. I am using the stock computer with a generic Moates tune.
I knew I needed a larger fuel pump than stock so I installed a walbro 190L fuel pump and I installed a adjustable fuel regulator. Fuel pressure is 39 psi.
I installed the engine and it runs ok. I haven't had it dynoed so I don't know what power its putting out. But it feels sluggish. The EEC is not throwing any codes as I repaired those problems a while ago. I know I need the engine tuned so I started getting prepared. I installed a Innovate AFR wideband o2 sensor with controller and gauge. Looks like the engine is running lean at idle, the idle AFR is 14.7 to 16. The cam has a good lope to it so maybe thats why the AFR varys or it needs a better tune. Cam Specs: Lift: .556in /.515ex 1.6rr
Duration: 224in/236ex @.050
Which brings me to the injectors, I read somewhere that the 30lb injectors supports up to 408 hp @ 85% duty cycle. Now I'm thinking the injectors are not large enough for my set up as my engine puts out 445 hp. Maybe thats why its running lean? I'm sure the fuel pump is large enough.
Do I need to go to 36lb injectors?
I attached the dyno sheet
Mike

 

[90silverstang]

Anyone?

 

[Exile]

For a 347 id say 42lb injectors & a 255lph fuel pump?

 

[reldla1996]

I'll second the 42# injectors and 255 lph pump. I've got a 190lph pump on my 369, dynoed at 425 rwhp, and it was running out of fuel at the top end. I should have went 255, and will be soon. On injectors, I went with 42#, though 36# would have been enough. When I was sizing injectors, I thought about using 30# (I already had them bought for when I planned a 331), but concluded I was going to be at 100 percent duty cycle, or maybe a little beyond. AFR of 14.7 to 16 at idle is fairly normal - I wouldn't worry about that.

 

[liljoe07]

Overlap in the cam will throw your idle AFR readings off. I wouldnt worry to much about your idle AFR. You can go pretty lean and not hurt a thing. Mine idles around 18:1 on the Wideband.

 

[90silverstang]

Overlap in the cam will throw your idle AFR readings off. I wouldnt worry to much about your idle AFR. You can go pretty lean and not hurt a thing. Mine idles around 18:1 on the Wideband.

Thats what it looked like to me. The cam overlap was causing the AFR variations.
But there is still this question. I would think with a 347 with a potential of 445 hp at the flywheel I would have plenty of power, but it feels sluggish. Will a tune make a difference?

 

[MikeH686]

You talking top end feels sluggish? What is your head size your motor might be running out of breath

 

[90silverstang]

Running Dart Pro 1 195cc heads and BBK 1 3/4" long tubes

 

[MikeH686]

Ok nevermind because i was gonna say if you have small heads you could be running the thing outta breath but those seem to be large enough

 

[90silverstang]

Today I adjusted the roller rockers to be sure they were good. I noticed when I took out the spark plugs they were really white. I remember I changed to a different plug. The engine builder used Autolite 3922. I changed them to NKG R5671A-8 about 6 months ago. I changed them back to the 3922. Will see how they work.
I changed the vaccum line from the the fuel pressure regulator to the vaccum port on the intake manifold near plenum. I was connected to the vacuum port close to the EGR spacer on the intake mainifold. This is the Edelbrock perfomer rpm II.
Is there any difference which vacuum port is used? Checked all vaccum lines, all ok

 

[DonMaximo]

I too have a T&L 347 and my 30lb injectors are working just fine.

T&L are now out of business...have been a for a little while now. If you google it, you'll find a wake of dudes who are or were not happy.

I recently checked my compression and found 2 weak cylinders. I followed up with a leakdown, and confirmed that my heads were losing power through 2 intakes valves. I'm all but convinced those guys pulled heads from the box and slapped them on with no prep. I say this too because they had a bunch of customers waiting on their orders... I suspect you didn't receive your crate when they said you would.

In any case, I would do a compression test on all cylinders... and if you find weak -or- cylinders beyond 10% of all others, do a leakdown test. I brought my heads in for a 3-angle and the local shop also shimmed my springs correctly.

In all sincerity, I hope you don't have the same issue as me.

I'm also using a Moates QH, Binary editor, and LC-1 WB sensor. My N/A induction is slightly different than your, but if you have an A9L ECU and Standard tranny, I could send you my binary file and you can load it into your ECU. Hell, you can always remove it if it's more trouble than your existing tune.

Last, eectuning.org has a few very helpful dudes who can help you with your tune. They will need your datalogs and binary file in order to make recommendations.

I wish you well.

-D

 

[90silverstang]

I too have a T&L 347 and my 30lb injectors are working just fine.

T&L are now out of business...have been a for a little while now. If you google it, you'll find a wake of dudes who are or were not happy.

I recently checked my compression and found 2 weak cylinders. I followed up with a leakdown, and confirmed that my heads were losing power through 2 intakes valves. I'm all but convinced those guys pulled heads from the box and slapped them on with no prep. I say this too because they had a bunch of customers waiting on their orders... I suspect you didn't receive your crate when they said you would.

In any case, I would do a compression test on all cylinders... and if you find weak -or- cylinders beyond 10% of all others, do a leakdown test. I brought my heads in for a 3-angle and the local shop also shimmed my springs correctly.

In all sincerity, I hope you don't have the same issue as me.

I'm also using a Moates QH, Binary editor, and LC-1 WB sensor. My N/A induction is slightly different than your, but if you have an A9L ECU and Standard tranny, I could send you my binary file and you can load it into your ECU. Hell, you can always remove it if it's more trouble than your existing tune.

Last, eectuning.org has a few very helpful dudes who can help you with your tune. They will need your datalogs and binary file in order to make recommendations.

I wish you well.

-D

Don--
I had my problems as well.
I had a rocker stud break off on a exhaust valve a while back. let me tell you --- when the exhaust valve doesnt open it backfires through the intake runner while the intake valve is trying to open, not pretty. It bent the intake push rod because of it. Also damaged the air temp sensor that was in that intake runner. I changed all the rocker studs to ARP plus I changed the roller rockers to comp cams gold 1.6 rr's. Also changed all the push rods to trick flows and measured for the correct geometry.
Has been running ok for a while, but I feel that the engine is sluggish.
A few days ago I removed the upper intake and valve covers to inspect the geometry again and the rollers a running in the middle of the valve stems, all ok. I readjusted the roller rockers for piece of mind.
Fired up the engine and the AFR still running lean 18- 19 afr.
I went ahead and checked the base timing and adjusted to 10* which it was close already.
Checked the fuel pressure, was at 39psi adjusted up to 45 psi. The AFR is running at around 14.7 to 15.5 now, much better.
How is your power on your 347? are you running Fuel Injection?
Mike