Pulling no punches....Hilborn fuel injection is killing me.

Generally speaking, this is a pretty easy setup to deal with. But, since the recent overhaul of the Fly and the motor, it runs like ****.

Here is the pertinent information.
270 CID Chevy
12.5-1 forged aluminum slugs
Crower roller cam
somewhere around .500" lift
duration around 300 adv
1.5-1 ratio rockers
Hilborn fuel injection
6a nozzles, pg150-0 pump
1.94-1.72 461 heads
powerglide ****** with a 3500 stall convertor
5.14 rear end gear

The car will not build RPM's, could not get the r's over 5,000 under acceleration.

Car idles OK, but drives like a Chrysler LeBaron around the 60 ft mark. Pops a little out of the exhaust, (sign of being too fat...the mixture, not me)

I talked to Hilborn and Joe Hunt mags today and they both say too fat. We used the exact pill size that was used in 1962 with that very engine. Same injectors, smae motor.
The only things that have changed is the pump is a different pump and the pill box is a new one.
Any ideas?

Root

 

What do you have the mag set at BTDC?

 

There is 12 degrees built into the mag comes in at 2500, 36 degrees total. So I guess my answer would be 12 degrees static.

 

I'm sure no expert, but I'd say your new pump is putting out a bit more than the old one. The engine overhaul may have made a difference in what it needs, too. You may ultimately need a high speed lean out if you don't already have one. I wouldn't jump for it right away though. Disclaimer: I have never tried to tune a fuel injection setup. This is just based on stuff I overhear at the strip.

 

The high speed lean outs I think are more for the higher rpms like over 6500 or so when the pump's volumetric efficiancy is higher than the engines. I just wish I could get to 6500.

 

How much fuel pressure have you got? We ran Lucas timed injection in 2 Liter Can Am,wouldn't run for **** without 120 PSI fuel pressure. Ignition timing? I'm ***uming ALL your ****erflies are opening completely.Any chance the new fuel pump is putting out alot more fuel than the old one? Are all the fuel lines new? I was always told mechanical injection works well at idle OR full throttle;not both.

 

There isn't a lot of pressure like on the systems you indicated. I asked that question and Hilborn says pressure really isn't that much of a factor. Volume is.

 

I would have to say that the new pump is to blame... if they weren't flowed all together, I'd say that you'll be chasing it around until the cows come home. Maybe send it all off and have Kinsler check it out... I hear they are about the best, expensive, but my buddy who drag races boats swears by them... along with another friend sho races Bonneville... and another friend who drag races.
FWIW, I would love to get my system up and running for the BFD... but the sticker shock on doing it right is too much for our Top Romin budget right now...
And you guys are running gas, right? Maybe the 150 is set up for alcohol? Have you tried the biggest pill in your pill ***ortment? Does it improve?

Also, about ignition timing... did you degree the cam? Is the balancer new? They come one of two ways... for two different timing pointers... if you're shooting in the dark with a bad timing mark, try running the RPM up until the mechanical advance comes in... then advance it until you hear a little "pop" out the exhaust... and then back it down a "tad"... then drive it...

Also, what do the plugs look like?
Sam.

 

See the pumps are all the same for the alcohol and the pump gas from 200"-400" motors. It really shouldn't matter on the size since the return is what decides your lean/fat mixture. It is the same pill that it always ran and the nozzles are setup for small cubic inch motors. None of which have been changed. I asked about flow testing and Hilborn says that wasn't my problem......

 

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There is 12 degrees built into the mag comes in at 2500, 36 degrees total. So I guess my answer would be 12 degrees static.

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12+12=24 not enough if you static timed it.
If this isn't how you did it, run it up to 3000rpm and set the mag at your 36º, then you'll know it's right.

 

There is 12 built in ...sorry.
I actually set my total and didn't really worry about the static. We have a "buzz box" for the points to verify.

 

Have you verified that the timing mark is correct with a degree wheel?

Also, what do the plugs look like? Do they verify that you are indeed running rich?

Sam.

 

No, the plugs don't really show ANY color really. The guy told me you can't really go by that since they need a few miles on em to really verify.

I have not used a degree wheel but The balancer is the same one that was used for 40+ years. The cam was a different grind though.

However, we did advance the timing gear 2 degrees on the cam as opposed to running it on the original keyway. We did verify that TDC was indeed TDC with the head off.

 

I say screw the setting of timing with the advance and compensating. Mark out the dampener to whatever the total timing should be and mark it. Rev it up to well past when the advance should kick in, and set the total timing. I don’t know what small chevys run for timing, but my 413s get set at 36-38 total.

If I have big problems with one of my race motors, I swap off a few suspect parts for ones off one of my good running cars. I'd make sure the motor is put together right by swapping on a good setup for barrel and seeing what happens.

Did your dampener slip? Did you check it when you degreed your cam? And you did degree your cam right?

My dad and I went through the same frustration when he put together his ’63 Plymouth race car. Would not rev past 5000rpm. It took 3 years to figure out it was a bad carter carb, that had come off a parts car we bought. It was dumping in way too much fuel, apparently due to a bad casting. You’ll figure it out. Dave

 

When you go bigger or smaller with the pills, does the condition get better or worse either way?
Sam.

 

I am afraid to say I don't degree cams. Maybe I should but, There's really nothing you can do if it doesn't line up anyway ,right?
I guess I could rescribe the balancer but it was right on the money. I used a dial indicator to locate tdc.

 

I have seen over and over that when people replace that older worn pump with new one, the smaller pill they were using to compensate for the leaky pump makes things too rich. I'd try what they say and lean out the engine. If you put in a bigger pill and it gets worse, wrong answer. If it gets better, bingo! Of course, change only one thing at a time.

 

Not really sure Sam. We made 2 p***es both which ****ed.
Then started changing stuff but ran out of time. Gonna try some more troubleshooting tomorrow maybe.

 

Jim, it was also a used pump.

 

Maybe not quite as used. I'd still try leaning it out. Sometimes the experts are right.

 

I agree Jim.

 

i am not trying to be an ***hole here, but if you did not degree the cam in you have no business advancing or retarding the cam gear, you dont know if it is already advanced or not. and yes there is something you can do about it if it is not right, that is why you degree the cam in the first place.

 

I had no specs to begin with. So should I just put it back?

 

btw, could this cause some of the symptoms mentioned RACEFAB?

 

I'd put a holley on it and a distributor back in it and get it working good with that first, then you'll have a baseline, and then put all the fancy stuff back on it ... then you'll know how good the cams is, if its installed correctly etc..... To me it seems kinda small for a Drag Car..... GOOD LUCK..... LUKESTER

 

[ QUOTE ]
I am afraid to say I don't degree cams. Maybe I should but, There's really nothing you can do if it doesn't line up anyway ,right?
I guess I could rescribe the balancer but it was right on the money. I used a dial indicator to locate tdc.

[/ QUOTE ]

Holy ****! I'd run out there right now and pull that thing apart and degree that cam. If you have a dial indicator and a degree wheel you can degree a cam. If you don't know how, I could walk you through it. It would take me longer to type it than it would to actually do it though.

What the idea is behind degreeing a cam is make sure it's in right. If the chain is off by a few degrees, crank off by a few degrees and and cam off by a few degrees, now the cam is off by a whole bunch. The only way to get it correct is to degree it. You change it with an offset bushings http://www.jegs.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=112048&prmenbr=361
drill the index whole out to the size of the bushing. It's easy. Dave

 

it could be, i dunno, you say that was one of the changes made to the engine. i have had some come in the shop where guys thought they were advancing or retarding, when in fact the cam was way off to begin with. i would pull it apart, find out the specs on the cam and install it straight up to begin with, but do it with a degree wheel, and verify the cam is where it is supposed to be.

 

Root the nozzle size you have is correct 260 thru 315 cu in. The pump is also correct 200 cu in to 400 cu in.I think youre problem lies in the barrell valve. Im sure you have turned the link in and out screwing with the idle. You need to do a leakdown on the barrell valve.Unblown on gas you should be around 18 to 22 per cent. Also check both of youre your byp*** valves make sure the arrows are pointing the same way the fuel is flowing.Stuck poppet in main byp***.Main or high speed byp*** installed backwards arrow against fuel flow.Tank vent too small.Restrictive or kinked byp*** lines. I think I mentioned before to get the hilborn and kinsler books THEY ARE CHEAP FOR THE INFORMATION THEY GIVE!!!I would double check your byp***es and leak the barrel valve. If that dont work send it to Hilborn. Don and Vern will tune it up and send it back, then it will work. They did mine with pump under 300.00 ---FEDER

 

[ QUOTE ]
I'd put a holley on it and a distributor back in it and get it working good with that first, then you'll have a baseline, and then put all the fancy stuff back on it ... then you'll know how good the cams is, if its installed correctly etc..... To me it seems kinda small for a Drag Car..... GOOD LUCK..... LUKESTER

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have you heard this before root?

 

Not to over simplify the problem, but you didn't mention everything that was done in your overhaul. Are you sure that you're not just floating the valves??? that will kill the revs and give you pops.