Idle EGT temps

I did exactly this today and was making good progress until I pissed off the neighbors. I guess running the engine 3 days in a row at dinner time was pushing my luck.
Thanks for the tip, I think I am going in the right direction now, just need to keep tweaking it till its managable

 

I think some guy get too hung up on leak down of the barrel valve while it's great to get you close your still gonna have to play with the BV usually to get the correct idle but definitely I believe the high idle EGTs are because your so rich and building a header fire , I too am running an XR-1 14/71 on a BBC and it's a very good blower and unless you don't plan on running much OD I question the 110 pump especially with such a large main jet, I run a 990 almost 3 home bigger than the 110 and I run a .95 main with 38%OD on a 555 ci and that blower makes over 40 lbs @8,000 rpm and I also agree you should drop your port check down to 6-8 psi and start with a 100 main, make sure your butterflies are set .009-.010" and adjust the barrel valve to get the correct idle and if you're convertor is tight sometimes it's harder to stop the surging in gear, good luck!

 

I have not seen the fuel flow (flow meter) mentioned anywhere....

The way I set my stuff is
1) Set blade opening to 0.010 in
2) Start with the idle fuel flow (0.75 Gal/min for my setup)
3) Adjust the blade opening and BV to get to 1750 RPM @ 0.75 Gal/min

Really care to much about the EGT at idle. If I idle it for a long time and the blades start to ice it will start to surge but otherwise it idles very smooth.

 

So whats your thought on Idle check pressure, Jim at Enderlie likes it low in the 5-6psi range, others like it in the 10-12 range

 

Thanks Will for taking the time to make such an informative post. The push fittings is a great idea, in fact Steve Jr wants to install a metering valve we have to adjust the air inlet and take the pressure off the blades. It has also been suggested to drill and extra vent hole in the hat nozzle bodies and that may help with distribution a little, right now I am showing 0 pressure on the hat line after the BV because the lines are actually under a vacuum at idle with the blower sucking so much. I can get it to idle pretty smooth at 2200 then it goes to crap when put in gear. Working on getting a converter special built to address this issue, the one in the car is on loan, but did come out of a blown TD running 3.80 in the 1/8th

As far as Randy goes, agree with you 100% on his knowledge, in fact I went to High School with Shelly, she was a couple of years behind me and remember when his Dad first started building heads and manifolds in his garage in the covina hills when I was hanging around the TA seen back in the early 80s. Problem is I would bet you 100 bucks I would still have the surge issue even if he flowed the system, without him having my blower, manifold and camshaft theres not way he would know how it would act at idle. He knows exactly what works and what dosent on the screw blown TAD TAFC and Pro mods stuff with his dads and AJ motors and I am sure he could make a huge difference in the overall learning curve for anyone like myself getting started with a blown alky combo and it is certainly not out of the question in the future to send him my system, but right now I got to get this surge under control so I can stage the car properly.

 

I'm curious, no one has mentioned what the timing is. From past experience we could eliminate the surge with just a few degrees of timing in our bbc's and sbc.
Is this wrong? Could he maybe have a timing issue?

 

27* currently

 

I don't understand either but advancing the timing at idle helped the surge in our BBC. I put a grid on and have 38 deg at idle, then back to 30 over 2200rpm.

 

I have been watching this thread because Steve and I have the same blower and hat and very similar pumps and I also have the same surge problem, it's fine when it's not in gear, but as soon as I put it in gear it starts surging. I have tried almost every suggestion mentioned here (and more) with no luck. Steve and I have discussed this outside of this forum. Right now we are thinking that when it goes into gear that the converter drags the RPM down enough to slow the pump, which leans the engine then that speeds up the engine and it goes rich (or actually where it should be) and that slows it down and starts the vicious circle of lean, rich, lean, rich, etc. On my car the idle surges about 800 RPM in gear and the pump pressure (at the pump) goes from 17-32# while it's surging, I would think that has to be affecting idle mixture. I have the idle set at 2250 out of gear, I wish I could tell you how much it slows down when I put it in gear, but the surging starts as soon as I put it in gear. Best I can tell the RPM drops to about 1600 when I put it in gear, but like I said it's pretty hard to tell.

Thoughts?

 

The idle check is at 10#, I have no high speed or pump loop. The port check is at 25# and pump saver is 130#

 

I haven't tried that, Mike. I'm going to play around with it at the shop this weekend to see if I can cure it, or at least make it better. I will try that.

 

A question I have is how do you know what the pressure is at idle between the BV and distribution block? I have a sensor at the pump reading about 19lbs at idle, the sensor after the barrel valve reads 0. Jim at Enderlie said it is because the hat lines are under a vacuum. Had a discussion today with Randy at RPM Performance the maker of my data logger about this. He said of course there is pressure there but it reads 0 because the sensor reads in PSIG which references atmospheric pressure which is 14.7 and being there is a vacuum in the hat it only will read 0 until the hat line is at 14.7 absolute pressure. unless you have a PSIA sensor which references 0 but your numbers would not match anything anyone is using for reference.
So my question would be if you set the port check to a lower pressure, say 15 psi to add fuel to the ports to aid distribution how would you know if it is opening or not since you cant read the actual pressure at idle?
I think a flow meter would be a huge help but at just over $1000 to add thats tuff at the moment.

Like Brian said, I can make mine run clean around 2200 but as soon as you put it in gear it goes to crap, If I raise the idle to 2500, its a little better in gear but pulls thru the brakes when the surge goes up. I think the converter is key to this and am working with a couple of different converter builders to build a converter that slips like a clutch down low but locks up on top and I am told it it doable and hope to pull the trigger tomorrow.