wont rev - Page 2

goinbroke2 · 08-07-2014, 12:01 PM

Not to go completely in a different direction, but a personal experience.

Had a sbf that would hit 7000 in 1st (or neutral when I was getting mad) about 6000 in 2nd and 5800 in 3rd. Did all fuel and electrical diagnosing and was stumped. Was told valve springs by a well know engine builder but knew that wasn't the problem because the cam and springs were new.
Problem, the new springs were the wrong ones for the cam I had. Swapped springs and pulled to 7500 in each gear.
No load would rev clean, under load or engine accelerating slowly (in higher gears) and it would nose over and feel like the valves were floating. (hint, they were)

Just another area to look..

dwg4859 · 08-07-2014, 01:42 PM

they can test the modules? i will take it tonmight thankx

08-07-2014, 01:49 PM

When I had the problem, it broke up all over the place. It also wouldn't rev up either.

The valve springs must be good as well. I was talking about an IGN problem.

goinbroke2 · 08-08-2014, 05:46 AM

Ah, cool. I thought it was hitting a wall at 5200, didn't know it was breaking up all over.
Hopefully the module is the issue.
Good luck

Mark Yacavone · 08-08-2014, 01:34 PM

Quote:

Originally Posted by dwg4859

i don't have msd i have a hei only, the fuel pressure Gage never drops below 5 psi, do i need a msd?

I don't believe your ignition system is up to par for anything except maybe Street Bracket.
I would install (minimum) a 6A , Blaster coil outside the cap and away from heat, and a new pick up coil for insurance. Eliminate the trouble sources.
You're only talking about maybe 300 bucks (American)

Lee Valentine · 08-08-2014, 02:40 PM

What Mark said, HEI in a stocker. You,ve got to be kidding.

Geerhead55 · 08-08-2014, 11:56 PM

Quote:

Originally Posted by Lee Valentine

What Mark said, HEI in a stocker. You,ve got to be kidding.

X2
Danny Durham

Alan Roehrich · 08-09-2014, 11:11 AM

You'll never be able to count on a relatively stock HEI setup in a race car. The design was originally intended for engines that never saw the high side of 5500 RPM, and rarely ventured past 4000.

Sure, the aftermarket came up with several crutches over the years. Some work okay. But they're really intended for mild street use, or classes where the rules require stock ignition systems.

Anything that uses an HEI module, stock or aftermarket, will fail, and will never offer maximum performance.

You can "get by" using an empty HEI distributor, with only the magnetic pick up coil in it. But make absolutely certain you get a premium pick up coil for it, I have had the best results a genuine GM AC/Delco part. Also, be sure you have the correct unit for the rotation of the distributor. Do not put a pick up coil made for a clock wise rotation distributor in a distributor that rotates counter clock wise. A lot of people will tell you that it will work, but I have seen instances where it does not work well.

Billy Nees · 08-09-2014, 11:35 AM

I have had very good results over the years using the (relatively) late model EST GM "small cap" distributors with the pick-up coil connected to an MSD 6 or 7. Just make sure that you have the correct gear for your application.

Mark Yacavone · 08-09-2014, 02:06 PM

I agree on the OEM pick up coils, but the early ones move back and forth with the vacuum advance. I have seen the wires break. Therefore any used ones can't be trusted.
At least you want to pull on the wires to see if they're ready to break inside the insulation.

08-07-2014, 12:01 PM	#11
goinbroke2 Senior Member Join Date: Mar 2002 Location: NS CANADA Posts: 892 Likes: 1,624 Liked 392 Times in 153 Posts	Re: wont rev Not to go completely in a different direction, but a personal experience. Had a sbf that would hit 7000 in 1st (or neutral when I was getting mad) about 6000 in 2nd and 5800 in 3rd. Did all fuel and electrical diagnosing and was stumped. Was told valve springs by a well know engine builder but knew that wasn't the problem because the cam and springs were new. Problem, the new springs were the wrong ones for the cam I had. Swapped springs and pulled to 7500 in each gear. No load would rev clean, under load or engine accelerating slowly (in higher gears) and it would nose over and feel like the valves were floating. (hint, they were) Just another area to look..

08-07-2014, 01:42 PM	#12
dwg4859 Junior Member Join Date: Jul 2014 Location: oklahoma Posts: 33 Likes: 0 Liked 0 Times in 0 Posts	Re: wont rev they can test the modules? i will take it tonmight thankx

08-07-2014, 01:49 PM	#13
Todd Hoven Guest Posts: n/a	Re: wont rev When I had the problem, it broke up all over the place. It also wouldn't rev up either. The valve springs must be good as well. I was talking about an IGN problem.

08-08-2014, 05:46 AM	#14
goinbroke2 Senior Member Join Date: Mar 2002 Location: NS CANADA Posts: 892 Likes: 1,624 Liked 392 Times in 153 Posts	Re: wont rev Ah, cool. I thought it was hitting a wall at 5200, didn't know it was breaking up all over. Hopefully the module is the issue. Good luck

08-08-2014, 02:40 PM	#16
Lee Valentine Senior Member Join Date: May 2004 Location: Brookfield, CT Posts: 708 Likes: 13 Liked 319 Times in 68 Posts	Re: wont rev What Mark said, HEI in a stocker. You,ve got to be kidding. __________________ Lee Valentine 1661 STK

08-09-2014, 11:11 AM	#18
Alan Roehrich Veteran Member Join Date: May 2006 Location: Murfreesboro TN Posts: 5,113 Likes: 1,571 Liked 1,826 Times in 414 Posts	Re: wont rev You'll never be able to count on a relatively stock HEI setup in a race car. The design was originally intended for engines that never saw the high side of 5500 RPM, and rarely ventured past 4000. Sure, the aftermarket came up with several crutches over the years. Some work okay. But they're really intended for mild street use, or classes where the rules require stock ignition systems. Anything that uses an HEI module, stock or aftermarket, will fail, and will never offer maximum performance. You can "get by" using an empty HEI distributor, with only the magnetic pick up coil in it. But make absolutely certain you get a premium pick up coil for it, I have had the best results a genuine GM AC/Delco part. Also, be sure you have the correct unit for the rotation of the distributor. Do not put a pick up coil made for a clock wise rotation distributor in a distributor that rotates counter clock wise. A lot of people will tell you that it will work, but I have seen instances where it does not work well. __________________ Alan Roehrich 212A G/S

08-09-2014, 11:35 AM	#19
Billy Nees VIP Member Join Date: Oct 2002 Location: On a hilltop in Pa. Posts: 4,494 Likes: 3,596 Liked 7,732 Times in 1,739 Posts	Re: wont rev I have had very good results over the years using the (relatively) late model EST GM "small cap" distributors with the pick-up coil connected to an MSD 6 or 7. Just make sure that you have the correct gear for your application. __________________ Billy Nees 1188 STK, SS I'm not spending 100K to win 2K

08-09-2014, 02:06 PM	#20
Mark Yacavone Veteran Member Join Date: Mar 2002 Location: Miles From Nowhere Posts: 7,815 Likes: 2,904 Liked 5,121 Times in 1,952 Posts	Re: wont rev I agree on the OEM pick up coils, but the early ones move back and forth with the vacuum advance. I have seen the wires break. Therefore any used ones can't be trusted. At least you want to pull on the wires to see if they're ready to break inside the insulation. __________________ "We are lucky we don't get as much Government as we pay for." Will Rogers

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