Home | Register | Login | Contact Us

 
Auto Math
Classifieds
Forum
Gallery
Games
Garage
Tech Articles
Utilites
 
FAQFAQ    SearchSearch    RegisterRegister    Log inLog in    Log in to check your private messagesLog in to check your private messages    Forum Subscriptions1/4 Mile Table 

Won't rev past 4000 RPMS

 
Post new topic   Reply to topic    SMOKEmUP.com Forum Index -> Chevy - Small Block Gen 1
View previous topic :: View next topic  
Author Message
RaG
Member


Joined: 20 Dec 2002
Posts: 85

296.96 points



PostPosted: Wed Sep 21, 2005 10:04 am    Post subject: Won't rev past 4000 RPMS Reply with quote

I have had this same problem with my previous motor which I shared a couple of parts with the new 383.

I'm thinking its gotta be down to the ignition system you think?

I have a HEI destributor with an in cap performance Mallory coil, with just a parts store module. Could it be a the combination of the cheap module and the Mallory coil?

The car pulls strong up to 4000 and continues to pull, but just can't get past 4000 rpms @ WOT.

Of course I can wing up well past 4000 in park or neutral, is just an under load issue.

Is my 3310 750 Vac Sec Holley too big for my 383? I had to use the second to lightest spring to get the secondaries to open (i verified that with a paperclip on the secondary diaphram rod.)


I have fresh plugs, gapped to .040 (R43LTS for vortec heads)
Rather new performance wires
The timing is set @ 34 degrees @ 3800 rpm, the mech advance comes in correctly, initial is 12 BTDC
The vacuum advance comes in correctly also.
I have verified that WOT in the car IS WOT @ the throttle linkage.
I have verified that the fuel pressure is good @ the dual line inlet to the carb and doesn't fall off @ high rpms.
The floats are adjusted correctly also.

I'm considering a good module/coil, maybe a MSD module and a MSD in cap coil.

383 (9.7:1)
Vortec Heads modified for extra lift
Comp Magnum 1.52 Roller Tip Rockers
XE274 230/236 .487/.490 hyd flat tappet
RPM Air Gap w/ 750 vac secondary holley
2004r w/ 3000-3400 lockup stall, 3.73 gears

_________________
71 Chevelle
Gas Guzzler
Back to top
View user's profile Send private message
bill jones
Member


Joined: 21 Dec 2003
Posts: 171
Location: Salt Lake City Utah
4414.80 points



PostPosted: Wed Sep 21, 2005 10:49 am    Post subject: Reply with quote

-first thing I'd do is to knock the sparkplug gaps down to .030" (or even down to .025") and take it out and see what happens.
-If that .010" to .015" tighter gap makes a significant difference then I would also bend the inner cap terminals in much closer to the rotor tip.
-Make sure you haven't left out the center prong in the cap that grounds the HEI coil frame to the main body of the distributor.
-A V-gap NGK style sparkplug (at .030") make help as they require less voltage to jump the spark gap.
-If you have a 4500 ohm coil button and you can stand a little radio noise I'd get a zero ohm button from Crane or MSD.
-do you have a resistor wire coming from your keyswitch.
-Keyswitches wear out on old cars.
Back to top
View user's profile Send private message Send e-mail Visit poster's website
SMOKEmUP
PostMaster


Joined: 30 May 2002
Posts: 3169

65097.54 points


1979 Chevrolet Camaro

PostPosted: Wed Sep 21, 2005 10:02 pm    Post subject: Reply with quote

How did you wire the HEI when you put it in?
Back to top
View user's profile Send private message Visit poster's website
RaG
Member


Joined: 20 Dec 2002
Posts: 85

296.96 points



PostPosted: Wed Sep 21, 2005 10:32 pm    Post subject: Reply with quote

I just simply setup a relay, with the powersource being the battery terminal and using an ignition on wire from the fuse block to activate the relay.

thats was all the wiring required

_________________
71 Chevelle
Gas Guzzler
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic    SMOKEmUP.com Forum Index -> Chevy - Small Block Gen 1 All times are GMT - 5 Hours
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum
Home | Contact Us | Automath | Cam Files | Dyno Search | Forum | Garage | Picture Gallery | Reaction Timer

Copyright 1997-2016 SMOKEmUP.com All rights reserved.
Advertising Info     Disclaimer     Privacy Policy