poor acceleration - Team Camaro Tech
Tech 2000 Our previous General Forum
Replies ONLY - no new topics.

 
LinkBack Thread Tools Display Modes
post #1 of 13 (permalink) Old Mar 27th, 01, 07:48 PM Thread Starter
Tech Team
 
Join Date: Mar 2001
Location: fresno,ca
Posts: 32
Thumbs down

I recently put on a new carb, intake, cam and rockers. Now when i punch it from a stop it has no power and slowly builds up. Then once i get to higher rpms there is this almost rattling noise but i think it is a popping noise. I was thinking the vaccum advance could be bad i have an original distributor. Or maybe the fuel pump. I have a 67 327 by the way. Any help would be great.
Thanks, Tim

------------------
1967 camaro 327 coupe
Performance engine looks great, cherry red all flush
timsisdope is offline  
Sponsored Links
Advertisement
 
post #2 of 13 (permalink) Old Mar 29th, 01, 12:59 PM
Senior Tech
 
Join Date: Jan 2001
Location: skiatook, ok
Posts: 3,692
Post

Sounds like either serious valve float or detonation...either way, the engine isnt going to last long. Did you start out with a stock motor, and what parts did you add? Give a little more info and myself or someone else can help you get your combo tuned in.

------------------
375hp 78 Chevy truck
77 Chevy Nova
95 Chevy Lumina 3.4L
and building a 78 Nova
travis is offline  
post #3 of 13 (permalink) Old Mar 29th, 01, 07:28 PM Thread Starter
Tech Team
 
Join Date: Mar 2001
Location: fresno,ca
Posts: 32
Post

ya i started with a stock engine, but the compression was good and eveything sounded good. I put on a 208/216 durstion 426/454 lift crane cam, performer rpm intake, summit roller tip 1.5 rocker arms, pushrods, summit double roller timing chain, edelbrock 600 cfm carb. What could i do to fix this problem????

------------------
1967 camaro 327 coupe
Performance engine looks great, cherry red all flush
timsisdope is offline  
 
post #4 of 13 (permalink) Old Mar 30th, 01, 07:34 PM
Senior Tech
 
Join Date: Jan 2001
Location: skiatook, ok
Posts: 3,692
Post

Could be a timing issue. What is your initial set at? Try setting it around 12-14 degrees and see if this wakes things up. Also, you may need to do some serious carb tuning...get the edelbrock kit and follow the book on how to fine tune your carb. The performer rpm intake seems to me to be much more finicky than the regular performer style intake. I run the same 600 edelbrock on my current rpm equiped engine and had to change several things to get it to run right, even though it worked great out of the box on my previous engine. I had to fatten the primary and secondary side 1 step each, step up to a 7" enrichment spring, and put the accel pump rod i the middle position. This was after steping up from a 210/210 cam to a 224/230, going from a weaind low rise dual plane to a performer rpm vortec, and swapping the ported 882 heads for vortecs.

------------------
375hp 78 Chevy truck
77 Chevy Nova
95 Chevy Lumina 3.4L
and building a 78 Nova
travis is offline  
post #5 of 13 (permalink) Old Mar 30th, 01, 09:14 PM
 
Join Date: Mar 2001
Location: Maidstone Ont.CAN
Posts: 5
Post

Yes,it sounds as if the timing is out.Double check it making sure if you have vacuum advance,it is unhooked.12 to 16 deg initial is a good place to start.I figure the timing is retarded a mile.If you find it hard to set at these settings,you may have to recheck TDC on the compression stroke and re-install your distributer at #1.Good luck.
jeff82z28 is offline  
post #6 of 13 (permalink) Old Mar 31st, 01, 03:05 AM
Senior Tech
Eric
 
Join Date: Dec 2000
Location: Kentwood, MI
Posts: 8,097
Post

Sounds like a cam problem to me. Sometimes a new cam, usually if it's not broken in right, can toast a lobe. But more likely is that your valve springs aren't up to the job with your new higher lift cam. Could one be broken? You should really replace valve springs when you replace a cam, especially if you don't know what type of springs you have or what wear is like on them.

I'm assuming that you've checked the obvious, like two plug wires switched, or the + and - wires on the coil switched, etc. When you tear apart a motor to that level it's easy sometimes to get something switched when you put her back together.
Eric68 is offline  
post #7 of 13 (permalink) Old Mar 31st, 01, 04:35 AM
Tech Team
 
Join Date: Mar 2001
Location: monroe,mi,usa
Posts: 61
Post

i think eric68 is on it. plug wires switched is the first place to check. and valve springs are next up. ive broken valve springs before, didnt notice much difference at low RPM but higher up it sounded almost like a rod knock.

------------------
bottledpower is offline  
post #8 of 13 (permalink) Old Mar 31st, 01, 07:29 PM Thread Starter
Tech Team
 
Join Date: Mar 2001
Location: fresno,ca
Posts: 32
Post

ya i am pretty sure i broke the cam in right, i waited a while before i punches it. The negative and positive wires are right, the sparkplugs are right. I am not sure about a broken valve spring, but everything looked good when i did the engine. I am pretty sure that my vacuum advance is not working. I accidently left it unpluged yesterday and it ran the same. I was gonna try replacing the distributor and see where that takes me. And i will look into the broken spring.Thanks guys

------------------
1967 camaro 327 coupe
Performance engine looks great, cherry red all flush
timsisdope is offline  
post #9 of 13 (permalink) Old Apr 1st, 01, 04:17 AM
Senior Tech
Eric
 
Join Date: Dec 2000
Location: Kentwood, MI
Posts: 8,097
Post

You can quickly check your distributor advance curve with a timing light, a dial back light works best. Just put your timing light on and slowly rev the motor from idle to about 3000 RPM. You should see the mark slowly advance as RPM increases. At about 3000 RPM you should have around 34 - 36 degrees total advance (that's with everything hooked up). If the mark jumps around or you're only seeing like 25 degrees advance at 3000 - your vacuum advance could be bad.

[This message has been edited by Eric68 (edited 04-01-2001).]
Eric68 is offline  
post #10 of 13 (permalink) Old Apr 1st, 01, 07:05 AM
Senior Tech
 
Join Date: Jan 2001
Posts: 251
Post

I'd say you need to replace those springs. I got a gut feeling that's what it is. If you have a points type distributor it wouldn't hurt to replace it but I'd bet the valve springs aren't up to par.

You car can run fine without vacuum advance if the intial and centrifugal advance is set right. Try 12 intial and 24 centrifugal and see but I wouldn't rev it out til you replace the springs since they are probly the stock ones.

I can run no vacuum advance if I don't punch it too fast. If I do it'll bog down but that can be solved by running a little more intial.
Good Luck
67stock is offline  
post #11 of 13 (permalink) Old Apr 1st, 01, 08:47 PM Thread Starter
Tech Team
 
Join Date: Mar 2001
Location: fresno,ca
Posts: 32
Post

Ya i will definetly look into replacing those springs. I think they are the stock ones. I was gonna go talk to my mechanic friend this week and see what he thinks. I will keep you guys posted. How hard is it to replace valve springs. Just take off the valve covers and change them. Won't the valves drop into the cylinders. Well thanks again. Any more ideas would be well accepted.

------------------
1967 camaro 327 coupe
Performance engine looks great, cherry red all flush
timsisdope is offline  
post #12 of 13 (permalink) Old Apr 3rd, 01, 06:03 AM Thread Starter
Tech Team
 
Join Date: Mar 2001
Location: fresno,ca
Posts: 32
Post

I was talking to his one mechanic i know and he thinks that my jets are wrong. He told em to get a strip kit and adjust the jets lower. I hope it works.

------------------
1967 camaro 327 coupe
Performance engine looks great, cherry red all flush
timsisdope is offline  
post #13 of 13 (permalink) Old Apr 3rd, 01, 01:47 PM
Senior Tech
Bob
 
Join Date: Dec 2000
Location: Ct.
Posts: 1,142
Post

If you get an air fitting that is set up for the sparkplug hole, you can charge the cylinder with air from a compressor and change the valve springs with the heads on the car

------------------
Bob
Garnet Red 69/SS396/TH400/355 Posi
94 HD Dyna Wideglide
phel69 is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Team Camaro Tech forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address.
NOTE we receive a lot of registrations with bad email addresses. IF you do not receive your confirmation email you will not be able to post. contact support and we will try and help.
Be sure you enter a valid email address and check your spam folder as well.



Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may not post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome