Adding performance to a stock 350 - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Hotrodding Basics
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 11-15-2011, 08:01 PM
1972 El Camino's Avatar
Registered User
 
Last photo:
Join Date: Nov 2011
Location: Texas
Posts: 57
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Adding performance to a stock 350

So with a stock rebuilt 350 does a cam upgrade go with better heads or can one do one or the other?
Add a new cam and be crippled by stock heads or add better flowing heads and be crippled with the stock cam?

Would one gain much performance with a muffler with good flow while still using iron exhaust manifolds or not worry so much about the mufflers and get headers on the motor?

As you can see I'm thinking about what I can do to a stock motor that I could gain some performance. I know it's just daily driver and I won't be racing but am curious about maybe the next thing I would or could do.

I do have a performer intake and a Rochester quadra jet on it and am doing an HEI upgrade.

I appreciate all the feedback I can get,
Mark

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 11-15-2011, 08:22 PM
starnest's Avatar
elkyholic
 

Last journal entry: Center Link Installed
Last photo:
Join Date: Apr 2007
Location: Virginia Beach
Age: 60
Posts: 327
Wiki Edits: 0

Thanks: 4
Thanked 5 Times in 4 Posts
Basically a cam/head upgrade usually works better if done together.
The goal is to match the cam with the heads so that they work together.

Also, the work goes together, removing the intake and valve covers to remove the heads or access the lifters for a cam change. Seperately they differ by having to remove exhaust manifolds to remove the heads or the fan/water pump/timing cover and set to change the cam.

The right answer really depends on which 350 crate engine you have. What heads, cam, etc. Also, what car, how you use it, etc. Provide good detailed information (if you can) that helps everyone understand the situation to give you better answeres.

You will find good information available here and many rodders eager to help you figure out what you have, what you want, and how to get it.

Search first, you will find many of your questions have already been answered, if not - just ask.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 11-15-2011, 08:38 PM
streetbruiser's Avatar
Registered User
 
Join Date: Nov 2011
Location: Illinois
Posts: 76
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
A set of headers is the single best thing you can do for more power if you have to choose.
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 11-15-2011, 09:53 PM
Custom10's Avatar
my KARMA ran over my DOGMA
 

Last journal entry: SS
Last photo:
Join Date: May 2009
Location: Saskatchewan, Canada
Age: 49
Posts: 1,095
Wiki Edits: 0

Thanks: 14
Thanked 25 Times in 23 Posts
Quote:
Originally Posted by 1972 El Camino
So with a stock rebuilt 350 does a cam upgrade go with better heads or can one do one or the other?
Add a new cam and be crippled by stock heads or add better flowing heads and be crippled with the stock cam?

Would one gain much performance with a muffler with good flow while still using iron exhaust manifolds or not worry so much about the mufflers and get headers on the motor?

As you can see I'm thinking about what I can do to a stock motor that I could gain some performance. I know it's just daily driver and I won't be racing but am curious about maybe the next thing I would or could do.

I do have a performer intake and a Rochester quadra jet on it and am doing an HEI upgrade.

I appreciate all the feedback I can get,
Mark
Is that the original stock 350 mill in the 72? there were a couple 350's in 72 which one do you have?

Sounds like you just want some more grunt without going over the top.

For strictly bolt on stuff a good dual plane, a worked Qjet, headers and free flow exhaust, correctly curved HEI and you can really pick it up under 4500 rpm leaving the heads/cam stock. Maybe 3:73 gears. A posi is real good idea in a elkymino too. But it will never be a street fighter just a nice crusier.

This is all good if the base motor ie rings, bearings,timing chain, heads etc are all in good shape. What ever you do keep the original 350 and all the original pieces.
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 11-15-2011, 11:18 PM
Registered User
 
Last photo:
Join Date: May 2009
Location: S/E Michigan
Posts: 653
Wiki Edits: 0

Thanks: 0
Thanked 9 Times in 9 Posts
Need more info about the vehicle to make good suggestions, but a good HEI with proper ignition curve, increase initial timing, small tube headers with full dual exhausts, carb recalibrated to match the timing and exhaust improvements, and a lower rear axle ratio(higher numerically) will provide the best bang for the buck.
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 11-16-2011, 06:04 AM
1972 El Camino's Avatar
Registered User
 
Last photo:
Join Date: Nov 2011
Location: Texas
Posts: 57
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Thanks for the replies!
The engine is not original in fact it's my 5 motor in the car. I have had the elcamino since the 1983. It came stock with a 402 and I was young and dumb when I put a 350 in it.

I had a shop put in a new motor so i don't know which crate motor it is but it was a new rebuilt. again wishing I knew more when I did the new motor over a year ago.
Anything I can do to find out what I have?

The last 350 was out of a 72 chevelle and again I may have been better of having it rebuilt then buying what I have in it now?

I have a edelbrock performer 2101 and a Rochester QuadraJet from Shaun Murphy on it. I am about to put a HEI from summit racing in it. www.summitracing.com/parts/SUM-850001R/ I wonder if I made the right choice here?

So headers seem to be the way to go. So many to choose from?

Thanks again,
Mark
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 11-16-2011, 08:15 AM
Banned User
 
Last photo:
Join Date: May 2011
Location: N.E.
Posts: 385
Wiki Edits: 0

Thanks: 9
Thanked 6 Times in 6 Posts
Personally i don't like the whole going into the engine and messing with the internals route---along with the let's switch to a holley and intake which everyone and their brother seems to think is manditory.


However, i would like to discuss switching up to a not overly wild cam such as the L82?

i AM a big proponent of headers and switch rear gears. With lower gears you'll likely give up some mpg, but then again wouldn't you give up mpg if you went into the engine?
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 11-16-2011, 02:55 PM
1972 El Camino's Avatar
Registered User
 
Last photo:
Join Date: Nov 2011
Location: Texas
Posts: 57
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by against all odds
Personally i don't like the whole going into the engine and messing with the internals route---along with the let's switch to a holley and intake which everyone and their brother seems to think is manditory.


However, i would like to discuss switching up to a not overly wild cam such as the L82?

i AM a big proponent of headers and switch rear gears. With lower gears you'll likely give up some mpg, but then again wouldn't you give up mpg if you went into the engine?
hmmmm isn't adding a new cam "going into the engine and messing with the internals route"?
intake is a big part of the cork on motors as well as exhaust and then yes the brains being the cam and more airflow in the chambers being the heads.
im thinking the next logical step is opening up the exhaust with headers, i just don't know which route to go with that aspect... so many to choose from, long , intermediate, short, size ect.

thanks!
Mark
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 11-17-2011, 08:37 AM
Banned User
 
Last photo:
Join Date: May 2011
Location: N.E.
Posts: 385
Wiki Edits: 0

Thanks: 9
Thanked 6 Times in 6 Posts
i know, that's why i said however. Also, i feel this cam is not too wild yet may add some more mid and top end without sacrificing too much bottom end. As you may know alot of corvettes and z-28's had this cam.


i agree about the headers. In the meantime i "hear" that 4 into 2's are better than 4 into 1 headers.
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 11-17-2011, 07:38 PM
starnest's Avatar
elkyholic
 

Last journal entry: Center Link Installed
Last photo:
Join Date: Apr 2007
Location: Virginia Beach
Age: 60
Posts: 327
Wiki Edits: 0

Thanks: 4
Thanked 5 Times in 4 Posts
In general, headers and free flow exhausts will improve performance and would be essential to upgrading heads and/or a cam. However, for your engine there may not be much difference w/o these upgrades.

Conversion to HEI is a good idea, but also may not provide a significant increase in power. Ignition either works or it doesn't, unless you have cylinder pressure which inhibits ignition, there's not much power to be gained on changing to HEI alone. Again, upgrades like cam and heads can increase volumetric efficiency which could inhibit ignition, thus the HEI could be a big factor (although, remember that the early sbc's made plenty of power with points type distributors). I like the HEI for other reasons, they require less maintenance, are easier to set up correctly, and they are very reliable. They do tend to limit rpm to around 5000/5500 rpm.

As for your crate motor, they are not easy to identify because there are few books with specs. Do you have any paperwork from your shop that would have a mfg and a p/n? If not you could at least ask, they probably won't remember, but they probably use a regular supplier. Then with either a few stamping or casting numbers the mfg may be able to provide some specs.

Choosing a cam and/or heads really depends on what you've got. Also, adding headers, changing gearing, and other considerations are part of the choice. In general, you probably would do best with a milder cam, but then that's probably pretty close to what you have now.

Take the time to figure these things out and have a plan, that way you can enjoy cruising with the money you didn't spend on unimprovements and fixing problems you didn't already have.
Reply With Quote Quick reply to this message
  #11 (permalink)  
Old 11-17-2011, 07:52 PM
starnest's Avatar
elkyholic
 

Last journal entry: Center Link Installed
Last photo:
Join Date: Apr 2007
Location: Virginia Beach
Age: 60
Posts: 327
Wiki Edits: 0

Thanks: 4
Thanked 5 Times in 4 Posts
If you do decide on headers, for me it's a simple choice.

Hooker Competition, there have been thousands of them used on sbc El Camino's and Chevelles. They are good quality, will fit nicely, and offer great performance for any street driven application. Unless you are going to build a screaming stroker motor you don't need more headers.

Even if you have small exhaust pipes and stock mufflers, the headers will probably help. If you plan other upgrades, then at least 2" pipes (Not saying bigger won't be better, just not needed) and some free flow mufflers should be part of your plan. But, I usually wait until I need to replace them before I spend the money.

Last edited by starnest; 11-17-2011 at 08:06 PM.
Reply With Quote Quick reply to this message
  #12 (permalink)  
Old 11-17-2011, 08:07 PM
Registered User
 
Join Date: Nov 2011
Location: Sugar Hill
Age: 54
Posts: 33
Wiki Edits: 0

Thanks: 0
Thanked 3 Times in 3 Posts
The easiest way to get some decent results is to put a set of 1.6 rockers on the intakes. I would go with 1.5 on exhaust. At that time you need to make sure your pushroda sweep the center of the valve stems. Too short and it is to the intake side too long and it all be to exhaust side. Next I would have the distributor recurved by a professional to get full advance by 2500rpm ( 35* ).
Next I would see about getting a 1" 4 hole tapered spacer and a good low restriction air filter and nice radiuses air cleaner.
If you want a little more add an MSD module and an external blaster coil. I prefer Moroso wires but there are a ton out there.
If you do this you should be 20-30 rwhp better.

If you do headers I think Thorley used to make the best long tube street headers. If you run duals use a xover pipe. Magnaflow has great mufflers that make power.

All that other stuff makes power but requires a lot of teardown and parts matching is critical.
Reply With Quote Quick reply to this message
  #13 (permalink)  
Old 11-18-2011, 05:54 AM
1972 El Camino's Avatar
Registered User
 
Last photo:
Join Date: Nov 2011
Location: Texas
Posts: 57
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by raceman14
The easiest way to get some decent results is to put a set of 1.6 rockers on the intakes. I would go with 1.5 on exhaust. At that time you need to make sure your pushroda sweep the center of the valve stems. Too short and it is to the intake side too long and it all be to exhaust side. Next I would have the distributor recurved by a professional to get full advance by 2500rpm ( 35* ).
Next I would see about getting a 1" 4 hole tapered spacer and a good low restriction air filter and nice radiuses air cleaner.
If you want a little more add an MSD module and an external blaster coil. I prefer Moroso wires but there are a ton out there.
If you do this you should be 20-30 rwhp better.

If you do headers I think Thorley used to make the best long tube street headers. If you run duals use a xover pipe. Magnaflow has great mufflers that make power.

All that other stuff makes power but requires a lot of teardown and parts matching is critical.
so you dont think http://www.summitracing.com/parts/DTE-380-C/ are over kill for what i have?
changing out the rockers will improve it that much?
what do you think about this choice? it isnt in the car yet. - www.summitracing.com/parts/SUM-850001R/
what is the spacer for?
thanks so much!
Mark
Reply With Quote Quick reply to this message
  #14 (permalink)  
Old 11-18-2011, 05:57 AM
1972 El Camino's Avatar
Registered User
 
Last photo:
Join Date: Nov 2011
Location: Texas
Posts: 57
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by against all odds
i know, that's why i said however. Also, i feel this cam is not too wild yet may add some more mid and top end without sacrificing too much bottom end. As you may know alot of corvettes and z-28's had this cam.


i agree about the headers. In the meantime i "hear" that 4 into 2's are better than 4 into 1 headers.
you're saying that probably the cam i have in my engine is the same one corvettes and z28's used?
im doing my research on headers, thanks for posting!
Mark
Reply With Quote Quick reply to this message
  #15 (permalink)  
Old 11-18-2011, 06:03 AM
1972 El Camino's Avatar
Registered User
 
Last photo:
Join Date: Nov 2011
Location: Texas
Posts: 57
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by starnest
In general, headers and free flow exhausts will improve performance and would be essential to upgrading heads and/or a cam. However, for your engine there may not be much difference w/o these upgrades.

Conversion to HEI is a good idea, but also may not provide a significant increase in power. Ignition either works or it doesn't, unless you have cylinder pressure which inhibits ignition, there's not much power to be gained on changing to HEI alone. Again, upgrades like cam and heads can increase volumetric efficiency which could inhibit ignition, thus the HEI could be a big factor (although, remember that the early sbc's made plenty of power with points type distributors). I like the HEI for other reasons, they require less maintenance, are easier to set up correctly, and they are very reliable. They do tend to limit rpm to around 5000/5500 rpm.

As for your crate motor, they are not easy to identify because there are few books with specs. Do you have any paperwork from your shop that would have a mfg and a p/n? If not you could at least ask, they probably won't remember, but they probably use a regular supplier. Then with either a few stamping or casting numbers the mfg may be able to provide some specs.

Choosing a cam and/or heads really depends on what you've got. Also, adding headers, changing gearing, and other considerations are part of the choice. In general, you probably would do best with a milder cam, but then that's probably pretty close to what you have now.

Take the time to figure these things out and have a plan, that way you can enjoy cruising with the money you didn't spend on unimprovements and fixing problems you didn't already have.
it seems i would see an improvement opening up the exhaust with headers/exhaust system without doing heads or cam at this point AND be ready for those upgrades down the road.

my main reason for going to HEI is the for the maintenance aspect but i do believe it will perform better than a points system as well but when you say the HEI system will limit spark at 5000/5500rpm do you mean that points don't?

good advice. i will contact the vendor that they got the engine from and see what i can find out.

as well i am here trying to put together a plan of attack, thanks for posting!

Mark
Reply With Quote Quick reply to this message

Recent Hotrodding Basics posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
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 for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may 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


Similar Threads
Thread Thread Starter Forum Replies Last Post
stock 350 adding vortech heads merlinsta Engine 3 12-03-2010 12:24 AM
Performance Heads add in Chevy Hi Performance sdimpala64 Engine 1 04-29-2008 08:59 AM
Debating stock vs performance cam bearings CNC BLOCKS NE Engine 46 03-18-2008 11:03 AM
Adding mechanical advance - stock HEI Rhansen General Rodding Tech 3 02-20-2005 04:13 PM
extracting power form a stock 318 stock cam satelite413 Introduce Yourself 1 02-03-2005 11:28 PM


All times are GMT -6. The time now is 04:24 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.