Hot Rod Forum : Hotrodders Bulletin Board - Reply to Topic
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> Engine> trouble shooting chevy 350
User Name
Password
lost password?   |   register now

Thread: trouble shooting chevy 350 Reply to Thread
Title:
  
Message:
Trackback:
Send Trackbacks to (Separate multiple URLs with spaces) :

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.



Additional Options
Miscellaneous Options

Topic Review (Newest First)
09-01-2012 08:39 AM
cdminter59
trouble shooting chevy 350

Where is the location of the timing tab on your timing chain cover? Are you using a stock 8" balancer? Another thing the 305 cid chevy timing chain cover has the pointer at the 12:00 position. Can you get the casting number off the passenger side back of the block? There should be a number on the pad behind the alternator too. Small block casting date is located on driver side rear of block on flange forward of bellhousing. Once you know the date you know the position of the timing pointer or balancer. You can then find TDC. Don't forget to read this link from post #7. Great for timing engines. http://www.crankshaftcoalition.com/w...nition_advance. Here is another article on the different balancers and timing chain cover pointer location. http://www.crankshaftcoalition.com/w..._TDC_lines_SBC
08-31-2012 09:36 PM
Greg T "THEY" say a lot of things. I would not go any closer than 3" to 4" below idle vacuum.






.
08-31-2012 05:02 PM
78 monte They say to get a power valve 1" below idle vacuum for best results,I'm yet to have a need to swap one but I may try it myself when I start super tuning my ride.
If the engine is loading up clean/change the plugs,take her for a WOT blast,shut it down right away and read the plugs,try jetting down a couple sizes if its rich and repeat till the plugs read correct.
I'm not the most elaborate tuner in the world but I just play with everything and anything till I feel the engine has no more to give.Works well for me,prolly not the method one would wanna do on a $10K engine,but on my mild street mills it allways gets it done.
BTW I have similar crappy heads 993 castings on my engine 1.94s though,they will work fine for a street engine though up to 350HP/5500rpm.Your cam is a bit big for the heads flow,it will take away throttle response in exchange for top end the heads cannot support,but to say it will not run at all is wrong just won't run upto the cams potential.Idealy a cam in the 220@050 up to 230@050 range(in a light car or with stout gears)woulda been best.
I do get a little pissed when people knock stock heads,like anyone who doesn't have a pocket full of bills for aftermarket can't make power.
08-26-2012 03:50 PM
gofastz well i didnt expect that, us country boys dont have all the money for those flashy heads that flows for race cars and such, this is a 4x4 truck a (toy) not a musle car or race car or a drag car, i set the timing by ear it dont ping it runs like a race car down the road, put the foot down and she is all over the place, when i got the timing in the rite area the carb settle down some what, the rest of that idle issue i beleave is due to it loading up from haveing the wroung size power valve in it, when he gets one ill let yal know how it goes...
08-20-2012 05:06 PM
Custom10 "bottom-of-the-page cam"

Good One
08-20-2012 02:23 PM
thinwhiteduke Ditto what Greg T said.
08-20-2012 06:32 AM
Greg T
Quote:
Originally Posted by gofastz View Post
the heads are just a sets he had laying around 883's open chambers 2.02/1.60 valves, he used 150 domes to get the cr he wanted, the cam was degreed to the cam card dont ask idk, keep in mine this motor is in a 82' chevy 4x4, with a 4speed granny, 3" exhaust with super44 flowmasters...the carb is stock right out of the box....
You've got a piss poor combination and you shouldn't expect that cam to run at all with those heads and no ignition timing specs. If you're bent on keeping those snarly crap heads then you really need to replace that cam with something in the 215* duration range and call it a day.

If you want to run that cam prepare to replace the heads with something that will flow some air, use a piston stop to determine TRUE TDC and get a timing tape and bolt-on tab, limit your mechanical advance to 10* and set your initial at about 26*, then add 10* of vacuum advance with full manifold vacuum. Once this is done you'll be able to tune the carb to handle that cam.

It never ceases to amaze me how people use junk heads because they have them and then expect the mill to run with a bottom-of-the-page cam.
08-19-2012 09:39 PM
farmwalker
Quote:
Originally Posted by 496CHEVY3100 View Post
I guess that would depend if you spent your time researching a product, or spent you time trying to find childish sayings that you copied from another page
If this was directed at t-bucket, you should calm down. He was just pointing something out. That's the point of this website..
08-19-2012 05:10 PM
78 monte I just time by ear.Then if it fires on one click warm and don't kick back and don't ping when I stand on it shes in range.Then play with weights and springs and see what happens.
Course I'm cobbler........lol
08-19-2012 10:21 AM
gofastz the heads are just a sets he had laying around 883's open chambers 2.02/1.60 valves, he used 150 domes to get the cr he wanted, the cam was degreed to the cam card dont ask idk, keep in mine this motor is in a 82' chevy 4x4, with a 4speed granny, 3" exhaust with super44 flowmasters...the carb is stock right out of the box....
08-08-2012 04:11 PM
cobalt327
Quote:
Originally Posted by gofastz View Post
hey guys my buddy and i built him a 40 over 350 10.1 compression, comp cams bigg matha thumper (295) 486"/500" adv duration 295/313, okay high rise dual plan holley intake, and a holley 770cfm truck avenger, now the problem it has aratic ideling we pulled the vac it has 5in we adjusted the mixture while the vac gauge was hooked up, then went to idel it down it lunged down way too low ok if we idel it back up alil its way too high, the timing is off i think he has the wroung damper bc looking at the distributor it looks tobe retarded too much, put the light on it and its no where on the timimg tab its more looking straight down behind the water pump soo we pulled it down till it said 16 on tab still not running no better( adjusting the mixture on the carb helped) but didnt help the ideling problem......any help will be greatful guys thanx..
The deal to making the thumpr cam work is timing related. They require a LOT of initial timing. I do not recommend locking the timing at full advance for a street-driven vehicle very often, but this is one case where that is going to be the easiest thing to do.

That said, any time you can allow for a mechanical advance- even if it's only 10 degrees- you should use it. Locked timing is like a stopped clock. It WILL be correct... a couple times a day.

There's some info here that you can take a look at to get some idea of what's required. In your case, I would start w/using 20-26 degrees initial w/the rest coming from the mechanical advance. The total timing depends on the chamber design and head material, etc. With this set up you'll want to use a vacuum advance connected to ported vacuum as described in the linked-to page above.
08-08-2012 10:17 AM
vinniekq2 carb might need a couple mods to idle with that cam.It will also idle about 1000.get the timing issue fixed then come back to carb(float level,does it have an electric pump? regulator?,,, power valve number? modify primary throttle blade) takes a little tweeking,,,it will come
08-08-2012 06:41 AM
T-bucket23
Quote:
Originally Posted by 496CHEVY3100 View Post
I guess that would depend if you spent your time researching a product, or spent you time trying to find childish sayings that you copied from another page
Who are you aiming that comment at.
08-08-2012 06:30 AM
496CHEVY3100 I guess that would depend if you spent your time researching a product, or spent you time trying to find childish sayings that you copied from another page
08-07-2012 04:42 PM
T-bucket23 That cam does not idle well by design.
This thread has more than 15 replies. Click here to review the whole thread.

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


All times are GMT -6. The time now is 07:17 AM.


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.