440 what am I missing here?

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Cool Hand

Cool Hand

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so I built a motor home 440. Did it the right way as far as I am concerned. Have a good friend that is an engine builder. Been doing it for 20 years. We stripped it down took it to my local machine shop,and had it cleaned bored 40 over,and all the parts balanced. I used an eagle crank, forged pistons, and used the 240 powerport trickflow top end kit. We topped it off with fitech fuel injection and slapped it onto a b&m street strip torqueflight pushing the power into a 8 3/4 rear-end with 3:55 Yukon gears,and Eaton trutrac. So according to trickflow this combo should be around 620 hp. This is where the disappointment starts. The truck sounds great but just won't get up on rpms. I shouldn't be able to keep tires under it. My first thought is the torque converter. I got talked out of the 3000 stall by my builder,but after further research believe that is what I should have installed. Unfortunately I have researched it so much I have become a mechanical hypochondriac and anything seems to be a plausible issue. Any body have any ideas? I am going to swap the convertor first off just don't want to be disappointed if that doesn't do the trick.
 
Swapping a converter is a bunch of work. I wouldn't do that until I had checked all of the easy stuff. Compression check, firing order, double check timing, what do the plugs look like? How does it run at idle? What doe the vacuum gauge say? Good oil pressure? Have you replaced the FiTech with a known good carb to see how it runs? There are at least 100 things you should check on before you try a different converter.
 
As said, likely tuning. All the stuff Andy mentioned. A TF-headed 440 should roast rubber with even a stock converter.
What are the cam specs?
 
Andy's got this... the only way I could see it needing more converter is if it has a drag race only cam in it...
 
Not enough info however if you follow Andyf and everything seems not ready to fly apart stick it on a Chassis dyno for a couple of pulls.

Getting 600hp is not always text book. The easiest way is CI however even that can fall short with a bad combo. But yes, if you had 600hp you would be sideways in the street at will lol....

JW
 
If you’re running the TF cam, then I’m not so sure that’s a match made in heaven for a vehicle with the self learning type of EFI and a low stall speed converter.
It’s also going to want a pretty good exhaust system.
I’d like to hear more about what the vehicle is and how it’s set up.

As for the issue of “no power”, my initial thought is the EFI is having some trouble dealing with that cam.
 
Is the FiTech controlling the timing? If so that’s the first thing to go over. If it was set up properly, adjusting the timing is just a few clicks and a save away.
 
A cranking compression test would be happening if it were mine.
At least on a couple cylinders where the plugs are easy to get at.

Since it’s a hyd roller cam, it should be done pretty quickly after shut down, to try and catch it before the lifters bleed down.
 
AndyF said:
Swapping a converter is a bunch of work. I wouldn't do that until I had checked all of the easy stuff. Compression check, firing order, double check timing, what do the plugs look like? How does it run at idle? What doe the vacuum gauge say? Good oil pressure? Have you replaced the FiTech with a known good carb to see how it runs? There are at least 100 things you should check on before you try a different converter.
Click to expand...
Timing is good,oil pressure is great. Had a holley 850 on it before fuel injection went on was a pooch of the line then as well. Will smoke the tires if i tap the brakes, but even then seems like it should being climbing up on the rpms way faster
 
PRH said:
If you’re running the TF cam, then I’m not so sure that’s a match made in heaven for a vehicle with the self learning type of EFI and a low stall speed converter.
It’s also going to want a pretty good exhaust system.
I’d like to hear more about what the vehicle is and how it’s set up.

As for the issue of “no power”, my initial thought is the EFI is having some trouble dealing with that cam.
Click to expand...
Running 2.5 inch exhaust with Flowmaster super 40's. The cam is the trickflow cam that came with the topend kit. I will post the specs when I get home but I believe they are 296/300 with .60 lift. We built the entire frame from scratch using qa1 torsion bar front k member,and arms,and the rear is a four link with qa1 coil overs. The truck itself is a 1940 dodge. I will post some pics
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I've got to ask... How much compression, or what pistons and how far above or below deck? What thickness and brand of head gasket? Cam installed straight up or retarded? The symptoms are showing a loss of or inadequate to start with cylinder pressure. I haven't looked up the specs for the cam yet, but when I see those numbers I would not imagine it would work too well with less than 10.5:1 and probably needs more than that with at least a 3500 rpm stall converter.
 
“Timing is fine” means nothing to someone trying to diagnose a problem. What is the timing set at and what does the curve look like? Obviously the fitech isn’t controlling ignition, so tell us what the specs are. It sounds to me like it’s over advancing.
 
Right on TT, Right on. I'm just imagining the only way it's not blowing the tires off at every tap of the throttle is for it to still have motorhome compression. Get some compression test numbers and post back.
 
It may be doing exactly what he says....
Garrett Ellison said:
Here are the cam specs, 10:1, Minimum. And yes, the converter is junk here.
Click to expand...

108 LSA. Whoever is working with the tune better have an idea of how to clean up the idle and lowend. Without a doubt timing controlled spark. Andyf can chime in on that one. Neat truck anyways....

JW
 
TT5.9mag said:
“Timing is fine” means nothing to someone trying to diagnose a problem. What is the timing set at and what does the curve look like? Obviously the fitech isn’t controlling ignition, so tell us what the specs are. It sounds to me like it’s over advancing.
Click to expand...
I believe it ended up at 12, 36 all in by 2500
 
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