Messages

181

Spud Miller's Cave / Re: Got a problem. Probably fuel supply issue.

« on: March 26, 2017, 09:18:42 AM »

So it does sound to me like idle pressure is too low. I set up one at 9 PSI and going to try it. Now on the main mine is at 18 PSI. Makes me wonder if at some point someone got them mixed up? What is main supposed to be? Also with idle bypass basically set at zero that may explain why this motor has always been hard to start.

Going to try one thing at a time starting with raising idle pressure as it makes sense and data logger appears to back it up. Sure makes me think the main is off to.

182

Spud Miller's Cave / Re: Got a problem. Probably fuel supply issue.

« on: March 26, 2017, 08:18:14 AM »

Okay for the latest. I changed the pump, the line and put two huge filters and the supply problem is gone. That is the fuel pump pressure is staying good but I am still having same issue I had last year. When I leave off transbrake for the .400 Pro Tree with 4400 chip it leaves good and hard. But when I foot brake it the car will not run, it will stumble and bog. Even on the dyno this motor did not want to take a load at lower RPM. We ended up starting our pulls at 5500 RPM. When I footbrake if I leave from dead idle the car will run good but reaction times are terrible. When I bring it up to 2500 reaction times are good but motor is not happy right there. I know mechanical injection does not have squirters to enrichen it when you open throttle so it is set up fat to cover, I know it is asking a lot from injection to make it work clean through out the RPM range. Most are idling or wide open most of the time and I can make it work good at both but not 2500 RPM. Still I think something is not right and it could be better.
Now I have noticed something and need to verify. The pressure is on the main pill bypass is 18 or less. On the idle bypass it is very little probably less than 1 PSI you can easily blow through it and I can not get my leakdown tester to measure that low. Any air at all and it is leaking. I believe Enderle told me that should be 8 to 10 PSI. Do not have any idea what main should be? Note this is naturally aspirated and not a blown motor.

I want to check basics, does anyone really know what idle and main bypass should be set at?  Once again Thank you for your help and suggestions.

183

Front Engine Dragsters / Re: Alcohol fuel system maintenance between races

« on: March 23, 2017, 07:10:50 PM »

No Sir, I have never had any problems. I say that as I am having a problem now but I think it is a fuel supply problem and I had also made a bunch of changes in fuel system in off season so right now can not say for sure. Car is flat running out of fuel and laying over. Data logger has verified it but I am not sure I have resolved the issue yet.
I did drain the fuel and change the oil for the Winter but during season nothing special except get motor good and warm before I load it into trailer.  And first two test and tune days was decent but not quite where I need it to be, third TnT it was terrible.

184

Spud Miller's Cave / Re: dual injectorators

« on: March 23, 2017, 06:57:59 PM »

Okay, I think you are asking for trouble if you plan on running gas through any mechanical injection. Electronic injection yes, Mechanical- no. Especially on the street. They are hard enough with alcohol and alcohol is very forgiving and where gas is not.  Also since you use so much more alcohol the nozzles are much larger and that to makes it more forgiving.
With that said I think BEST investment you can do there is to dyno the motor with someone who knows mechanical injection. Have a bunch of nozzles, jets and bypasses when you do. A good dyno operator can get your tune on the money with just a few pulls. You could spend $150 a day and most all season going to the track and testing or you could spend $225 on dyno and have it right.
Mechanical fuel injection requires a good pump, properly sized nozzles and mains for the pressure you are working with to get right volume of fuel into motor. The motor requires x Lbs of fuel to make X Horsepower and it can be figured out mathematically to get you close if you know the pump size pressure, nozzles etc.

185

Spud Miller's Cave / Re: Cool or No Cool

« on: March 23, 2017, 06:43:22 PM »

I run a very small Honda radiator with a fan so I can control the temps especially when hot lapping in later rounds. You do not need much but I definitely prefer to have a radiator.

186

Front Engine Dragsters / Re: Trans to Rear Coupler Play

« on: March 21, 2017, 07:16:25 PM »

Thanks for that information I will be building a front engine dragster by end of year.

187

Spud Miller's Cave / Re: Got a problem. Probably fuel supply issue.

« on: March 21, 2017, 07:14:37 PM »

I did turn the inlet hose around and checked it. Hose seems good but turned it around anyway. Note, when I removed the hose the fuel flowed out like a water hose confirming to me the filters were not restricted. Just the same I put two HUGE stainless filters on there.
Tomorrow I plan on changing out the pump. I am very confident it is not the problem but I have it and will not hurt to try it.
I did check the vent and it is clean and open. May be able to put car up on jack stands, pull low RPM chip out and try it against transbrake to see if it is better.
I did not remove the barrel valve so it could not be turned around.
I went back to my original tune up and will see what happens on Sat.
Fuel shut off is closed, I have got into the habit of checking and double checking the fuel shut off and make sure transmission is in low gear before I stage. I also occasionally check operation of fuel shut off to make sure it completely closes.
Found a small leak on one of the fittings going into the tank and fixed it.

Thanks for the good  ideas and suggestions. Saturday is my first points race and I hate going into it blind and unprepared but I will do what I can. Hoped I would find and resolve the problem but right now have not seen anything firm as to what the problem is.  At least nothing definitive so far.

188

Spud Miller's Cave / Got a problem. Probably fuel supply issue.

« on: March 20, 2017, 06:10:37 PM »

I have Enderle hat on 760 HP SBC I had been making changes to try to get it to footbrake with little success. Now car has developed a bad problem and will not come up on converter. The data logger is showing fuel pump pressure drops like a rock, all O2 sensors read lean and car just lays over.
My first thought was loose fuel line and dirty filters causing pump to suck air and not fuel. Drained fuel cell, checked and cleaned filters and checked all fittings (they were tight). Fuel filters had a few little bit of trash but it was not much and filter was not clogged. Nothing more than I consider normal.
I checked the belt and the pulleys are good. The nozzles are clean and flowing and all O2 on all 8 cylinders are consistent so it is not a clogged nozzle.

I looked in the fuel cell for paper or plastic or anything that could float around and block outlet. Nothing, yet it sounds to me like it is a fuel supply problem. Car has been running very good with same system for several years. I do see a few things I could improve to make system better but it was working good before and I need to fix the issue here.  Most of the hoses are one year old and in good shape.

I will probably put my old tune up back in it and I have a new pump that I may try but I seriously doubt that is the issue. It is acting like it is starving for fuel and sucking air.  Note I am not that far off of old tune up now and it should be way fatter. Basically I am right now one size smaller nozzles and way smaller main so it should if anything be very fat right now but it is not and in my opinion it is somehow running out of fuel.

I have two large Summit stainless filter elements that go into a tee fitting and one -10 line to bottom of pump. No sharp turns or anything like that. Returns go into top of cell near the back. I am thinking of making a manifold to return the fuel back into inlet line near pump to reduce aeration of fuel. I think it would also help to keep inlet fuel flowing and pump covered with fuel. Now I found two larger filters and will probably get them and put them on, anything I can do to increase flow and lower restriction should help but the current filters are not the problem as they have been working well and were clean.

It is not ignition as logger is not showing any missing etc.

Any suggestions? Hope I gave you enough information to give me a direction to look. Thanks,

189

Front Engine Dragsters / Re: Alcohol fuel system maintenance between races

« on: March 19, 2017, 06:19:37 PM »

I have ran alcohol since 1998 and do not do much special. I do use top lube get motor good and warm to evaporate moisture out of oil before I put it in trailer. When I set up system I made sure everything was compatible with alcohol.

190

Front Engine Dragsters / Re: Finally made it to the track today

« on: March 19, 2017, 06:16:17 PM »

How did you hurt the engine?

191

Spud Miller's Cave / Re: More questions

« on: March 14, 2017, 07:59:17 PM »

Most problems with Mech injection on the street could be cured with someone making a seperate  accelerator pump system to come in just before off idle

Like an Injectorator.  Still I think it would be hard to make alcohol tuned good on the street even with Injectorator and it gets harder with gas.

192

Front Engine Dragsters / Re: Some basic simple questions

« on: March 14, 2017, 07:48:42 PM »

I always tighten my belts real tight and my arm restraints fairly tight but where I can still easily reach everything.  My seat is fairly tight so I will not slap around inside. I do not plan on ever crashing but if I do I want to walk away.

What concerns me and should concern all open wheel front engine drivers is fire. Now it does not happen often but could get real bad very quick.

193

Front Engine Dragsters / Re: Some basic simple questions

« on: March 12, 2017, 06:29:39 PM »

I do plan on running the wheelie bar and my motor combination is very close to what was in it. 760 Hp and should be easy 4.90- 5.0.
Driving an Altered I have learned about having it lined up right before you pull the trigger. Lol.

194

Front Engine Dragsters / Re: Some basic simple questions

« on: March 12, 2017, 05:52:25 PM »

Thanks for all of the great tips. I run an Altered 5.0 in NE2 and have been fairly successful but the dragster is a whole new animal. My Altered is a four link and I learned how to make it work. The dragster of course is hard tail and I know nothing about how to tune that.. Really looking forward to this and appreciate your help and suggestions. This dragster has been a very good working car so I should be okay or at least have a good starting point.

195

Front Engine Dragsters / Some basic simple questions

« on: March 12, 2017, 07:23:10 AM »

Okay I am thinking of getting a 225 inch front engine dragster. My questions are.
1. How do you set it up so it goes straight when front wheels are up?
2. How do you limit wheelies? Or is that even an issue with 225 inch car?
3. Any other tips for setting it up so it leaves hard and straight?

While I think I may know the answers I want to verify with people who have been there done that. Thanks,