Laying over

SUPER STREET ROB · 07-31-2011, 08:07 PM

Put a new 434 small block 18 degree heads on alcohol in the car last week. Went to MIR today to test it before I go to Atco next weekend. The problem im having is Its laying over in high gear. Its a turbo 350 3 speed trans. shift 1st and 2nd gear at 7000rpm's and when I put it in 3rd gear it goes to 6500 rpm's and stays there for the last 300 feet. I changed jets and return pills at the track and it made no difference. I checked everything in the fuel system. I called George Rupert and did everything he told me to do. So im kinda stuck here and wanted some ideas on what to do. The car is a 1980 pontiac Grand Prix that weighs 2755 pounds with a 430 gear.In 3000 feet of air today it went a 9.14 at only 143mph????????? with a 1.24 60'. in the 1/8 it went 5.77 at 118mph. Any help would be greatly appreciated........... Thanks in advance....Rob Derr

Adger Smith · 07-31-2011, 09:39 PM

What are you running for timing? What plug do you have in it? What ignition system?

SUPER STREET ROB · 07-31-2011, 09:57 PM

32 degrees timing crank trigger set up. 7AL box

Adger Smith · 07-31-2011, 10:05 PM

Plug? plug gap?

SG1809 · 08-01-2011, 08:44 AM

Quote:

Originally Posted by SUPER STREET ROB

Put a new 434 small block 18 degree heads on alcohol in the car last week. Went to MIR today to test it before I go to Atco next weekend. The problem im having is Its laying over in high gear. Its a turbo 350 3 speed trans. shift 1st and 2nd gear at 7000rpm's and when I put it in 3rd gear it goes to 6500 rpm's and stays there for the last 300 feet. I changed jets and return pills at the track and it made no difference. I checked everything in the fuel system. I called George Rupert and did everything he told me to do. So im kinda stuck here and wanted some ideas on what to do. The car is a 1980 pontiac Grand Prix that weighs 2755 pounds with a 430 gear.In 3000 feet of air today it went a 9.14 at only 143mph????????? with a 1.24 60'. in the 1/8 it went 5.77 at 118mph. Any help would be greatly appreciated........... Thanks in advance....Rob Derr

Convertor? Maybe to tight for the motor, Had a similar problem.
Pat
SG1809

Dave Steltz · 08-01-2011, 01:08 PM

Rob, for whats its worth, a couple of on-line calculaters I saw take the 5.77/118 and predict 9.15/146...so not that far off, and at 3000 feet...My brothers BBC Monte Carlo has been 9.17 in good air at 146 or so...

Couple of things maybe to look at if you havent...

EGT

What size carb ? If its the one off your other motor maybe not enough CFM ? I would think
you have a dominator right ?

The other thing, you said you made come changes based on what george said, but if it made no change whatsoever, I think I'd concentrate on the tuneup...On my terminator until I could make a change and actually see it in the EGT/water temp, every change I made, made no difference on the track...Maybe see if you can make it really fat or lean, then go from there...

Mickey Whaley · 08-01-2011, 01:51 PM

I was at that airport also

SUPER STREET ROB · 08-01-2011, 11:11 PM

Dave,
Thanks for the info. I talked to my engine builder today and he said he advanced the cam 6 degrees from what it was before and he said rertard 4 degrees and set the timing ad 30 degrees. so im doing that tomorrow then going to capitol on saturday and try it. I pray that this works..

Adger Smith · 08-01-2011, 11:27 PM

Rob,
That is good info from your engine guy. I was headed that way. He has increased the cyl pressure. You might need to close up the plug gap a little if you are running it pretty wide. I have found that big cu in engines with 18 deg heads don't like a lot of timing. The plug is located in the chamber high and close to centered. It doesn't need a lot of timing to get the flame front over the dome and get pressure rise. I would also use a non extended tip plug with alky and that head. The wet alky /air mixture hitting the hot exposed extended tip could ignite before the spark.
Good luck with the tune up.

07-31-2011, 08:07 PM	#1
SUPER STREET ROB Member Join Date: May 2008 Location: CONOWINGO MD. Posts: 119 Likes: 0 Liked 0 Times in 0 Posts	Laying over Put a new 434 small block 18 degree heads on alcohol in the car last week. Went to MIR today to test it before I go to Atco next weekend. The problem im having is Its laying over in high gear. Its a turbo 350 3 speed trans. shift 1st and 2nd gear at 7000rpm's and when I put it in 3rd gear it goes to 6500 rpm's and stays there for the last 300 feet. I changed jets and return pills at the track and it made no difference. I checked everything in the fuel system. I called George Rupert and did everything he told me to do. So im kinda stuck here and wanted some ideas on what to do. The car is a 1980 pontiac Grand Prix that weighs 2755 pounds with a 430 gear.In 3000 feet of air today it went a 9.14 at only 143mph????????? with a 1.24 60'. in the 1/8 it went 5.77 at 118mph. Any help would be greatly appreciated........... Thanks in advance....Rob Derr

07-31-2011, 09:39 PM	#2
Adger Smith VIP Member Join Date: Dec 2001 Location: Texarkana Ark/TX Posts: 2,446 Likes: 575 Liked 880 Times in 311 Posts	Re: Laying over What are you running for timing? What plug do you have in it? What ignition system? __________________ Adger Smith (Former SS)

07-31-2011, 09:57 PM	#3
SUPER STREET ROB Member Join Date: May 2008 Location: CONOWINGO MD. Posts: 119 Likes: 0 Liked 0 Times in 0 Posts	Re: Laying over 32 degrees timing crank trigger set up. 7AL box

07-31-2011, 10:05 PM	#4
Adger Smith VIP Member Join Date: Dec 2001 Location: Texarkana Ark/TX Posts: 2,446 Likes: 575 Liked 880 Times in 311 Posts	Re: Laying over Plug? plug gap? __________________ Adger Smith (Former SS)

08-01-2011, 01:08 PM	#6
Dave Steltz Member Join Date: Nov 2003 Posts: 323 Likes: 0 Liked 0 Times in 0 Posts	Re: Laying over Rob, for whats its worth, a couple of on-line calculaters I saw take the 5.77/118 and predict 9.15/146...so not that far off, and at 3000 feet...My brothers BBC Monte Carlo has been 9.17 in good air at 146 or so... Couple of things maybe to look at if you havent... EGT What size carb ? If its the one off your other motor maybe not enough CFM ? I would think you have a dominator right ? The other thing, you said you made come changes based on what george said, but if it made no change whatsoever, I think I'd concentrate on the tuneup...On my terminator until I could make a change and actually see it in the EGT/water temp, every change I made, made no difference on the track...Maybe see if you can make it really fat or lean, then go from there... __________________ Dave Steltz 135G SG/SP/SST BIAECH Racing Team

08-01-2011, 01:51 PM	#7
Mickey Whaley VIP Member Join Date: Dec 2006 Posts: 1,220 Likes: 0 Liked 1 Time in 1 Post	Re: Laying over I was at that airport also

08-01-2011, 11:11 PM	#8
SUPER STREET ROB Member Join Date: May 2008 Location: CONOWINGO MD. Posts: 119 Likes: 0 Liked 0 Times in 0 Posts	Re: Laying over Dave, Thanks for the info. I talked to my engine builder today and he said he advanced the cam 6 degrees from what it was before and he said rertard 4 degrees and set the timing ad 30 degrees. so im doing that tomorrow then going to capitol on saturday and try it. I pray that this works..

08-01-2011, 11:27 PM	#9
Adger Smith VIP Member Join Date: Dec 2001 Location: Texarkana Ark/TX Posts: 2,446 Likes: 575 Liked 880 Times in 311 Posts	Re: Laying over Rob, That is good info from your engine guy. I was headed that way. He has increased the cyl pressure. You might need to close up the plug gap a little if you are running it pretty wide. I have found that big cu in engines with 18 deg heads don't like a lot of timing. The plug is located in the chamber high and close to centered. It doesn't need a lot of timing to get the flame front over the dome and get pressure rise. I would also use a non extended tip plug with alky and that head. The wet alky /air mixture hitting the hot exposed extended tip could ignite before the spark. Good luck with the tune up. __________________ Adger Smith (Former SS) Last edited by Adger Smith; 08-01-2011 at 11:28 PM. Reason: sp