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> sbc build
User Name
Password
lost password?   |   register now

Thread: sbc build 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:
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)
12-18-2012 12:29 AM
techinspector1
Quote:
Originally Posted by southernculture View Post
I am getting ready to leave for afghanistan and am trying to get a order list for while I am gone.
Thank you Gary, for catching this. I missed it the first time around.
Thank you very much for your service young man, America is the Land of the Free BECAUSE of the brave. May God bless you and keep you safe.
12-18-2012 12:12 AM
1Gary
Quote:
Originally Posted by southernculture View Post
you make a very good point. I guess I need to determine how much go I want. I would prefer performance over sound. I have a lunati 10120701 cam and lifter new in the box in my garabe but looked at the specs and just a bit too mild for my application. I had been looking at the 702 and 703 voodoo's and was really leaning towards them, but I just heard the youtube of the mutha thumpr and liked the sound. I know The sound is not really all that important. This is gonna be ina 2500 lb truck and will have a manual trans! I am not in any hurry cause my truck is no where near done, and I dont have to install a cam in a motor as of right now, however I am getting ready to leave for afghanistan and am trying to get a order list for while I am gone. Thanks for the insight!
Thank You for your service.Take care of yourself and check in with us as you can.
12-17-2012 07:29 PM
southernculture you make a very good point. I guess I need to determine how much go I want. I would prefer performance over sound. I have a lunati 10120701 cam and lifter new in the box in my garabe but looked at the specs and just a bit too mild for my application. I had been looking at the 702 and 703 voodoo's and was really leaning towards them, but I just heard the youtube of the mutha thumpr and liked the sound. I know The sound is not really all that important. This is gonna be ina 2500 lb truck and will have a manual trans! I am not in any hurry cause my truck is no where near done, and I dont have to install a cam in a motor as of right now, however I am getting ready to leave for afghanistan and am trying to get a order list for while I am gone. Thanks for the insight!
12-17-2012 06:51 PM
oldbogie
Quote:
Originally Posted by southernculture View Post
Hey y'all,
I am building a 350 for my rat rod, 1953 3 window chevy pickup, and I have a question on cam selection. I have the short block built. I have had the motor bored .040 over, new crank and .040 speed pro flat top pistons. The heads I have are 906 vortec heads. I had them worked, new springs and the heads cut to allow for .550 lift. valve job and the heads were decked. I am trying to figure out what cam to run. I plan on having a 3.08 rear end and the trans is manual. I want it to sound rough at idle and I want it to run well from at least 2000-6500. I dont have an intake or carb yet. Thanks for the help.
Shaun
Read through this, I can sympathize with the rough idle cam, love the sound, but the Vortec head really isn't very happy with those old cam profiles. It is made for modern fast acting cams. While modern cam technology may not give that old school, cool, muscle car, sound; they git on with the show. You'd be much better off with a COMP XE 268 or a Lunati Voodoo 10120702. Depending on how you detail the engine out these cams make an easy 380 to 410 horses with a 350 and Vortec heads.

They are compatible with a stock torque converter, although about as far as you'd want to go, while delivering the bottom end torque a 3.08 axle will demand of the engine to make the car go decently from off idle to red line. The fast lift and fairly long LSA will not have the muscle car cam stagger but with the kind of compression you can build, the exhaust note will be sharp. Anybody that needs to know will know this is a motor to be reckoned with. The less informed ones can learn from your tail lights vanishing into the distance.

Bogie
12-17-2012 05:03 PM
southernculture I think I am sold on the mother thumper 12-601-4 looks like it will be a good fit spec wise for my motor and I do like the sound at idle! Thanks for the help.
12-14-2012 05:52 PM
hcompton Use the comp cams small hyd thumpr cam it will sound good and make pretty good power. But not real smooth at idle it will lope pretty good.

They make good power and sound good dont work on all engines but it sounds like you could run the small thumpr without it any issues. Sep for maybe some carb tuning. Alos most dyno resluts put the thumpr above other cams inhp because the thumpr design produces good peak hp number other cams can produce more average hp. Which is better for truck build with 3.08s

You can hear them on youtube alot of people have vids of the sound.
12-14-2012 05:34 PM
ap72
Quote:
Originally Posted by southernculture View Post
the gap from the top of the piston is .024 to the top of the block. I am the engine assembler. I have not changed the rear gear yet but was planning on a 3.07. The trans I have now is a saginaw 3 speed. I plan on getting a m21. but that is much later. I would rather have rough idle and more power than perfect drive ability it is a rat rod. I am fine with running it higher in rpms, I will be running roller rockers and upgraded pushrods. I dont have a head gasket yet so that gap is still open to arguement, when I did the calculation on the cr it was with a .40 head gasket. I will run pump gas!
DO NOT USE A .040" GASKET! The .015" spec'ed will be the best match for your combo.
12-14-2012 05:22 PM
southernculture btw the springs that were installed were comp, I am not sure of the specs however the heads were machined to allow .550 lift with these springs. New seats cut and new retainers.
12-14-2012 05:15 PM
southernculture I am not sure how much was taken off of the heads, by looking at them there is only raw metal on the corner of both of them.
12-14-2012 05:07 PM
southernculture the gap from the top of the piston is .024 to the top of the block. I am the engine assembler. I have not changed the rear gear yet but was planning on a 3.07. The trans I have now is a saginaw 3 speed. I plan on getting a m21. but that is much later. I would rather have rough idle and more power than perfect drive ability it is a rat rod. I am fine with running it higher in rpms, I will be running roller rockers and upgraded pushrods. I dont have a head gasket yet so that gap is still open to arguement, when I did the calculation on the cr it was with a .40 head gasket. I will run pump gas!
12-14-2012 04:46 PM
ap72
Quote:
Originally Posted by cdminter59 View Post
I have a question for you. What type of gas do you plan on using in this rat rod. I see you have a problem. You are going to use Vortec heads which are 64cc chamber heads. In your short block measure the distance from the top of the block to the top of the piston at TDC. You probably will have .025. This area from the bottom of the head to the top of the piston at TDC is call Quench. The recommended Quench is .040. So if you have .025 you will need a .015 head gasket. This setup will give you around 10.425 compression ratio which is too high for pump gas. If you use a .040 thick head gasket to bring the compression down the engine probably will ping under load. You need to talk to your machinist and motor assembler. The 12cc dish piston should have been recommended for using Vortec heads.
It's actually closer to 9.5-9.9:1 with 64cc chambers.

flat top pistons and vortec heads are probably one of the most popular combos in the past 15 years- it'll work just fine.
12-14-2012 04:44 PM
techinspector1
Quote:
Originally Posted by cdminter59 View Post
In your short block measure the distance from the top of the block to the top of the piston at TDC. You probably will have .025. This area from the bottom of the head to the top of the piston at TDC is call Quench.
Ummm, not altogether correct. The distance from the crown of the piston to the block deck where the heads bolt on, with the piston at top dead center, is called Piston Deck Height, not to be confused with Block Deck Height, which is the measurement from the centerline of the main bearing bore to the block deck where the heads bolt on.

Quench, also called Squish, is the distance from the piston crown to the underside of the cylinder head WITH THE HEAD GASKET IN PLACE and the piston at TDC. It is the sum of the piston deck height and the gasket thickness.

Quote:
Originally Posted by cdminter59 View Post
The recommended Quench is .040.
Ummm, actually, 0.035" to 0.045" is acceptable to most builders. I believe David Vizard found the limit at around 0.027", where he encountered a piston/head collision. I have no idea what the weight of components was, so that is another variable.

Not trying to give you a hard time CD, just trying to keep the nomenclature correct so that those who are learning from reading these threads will get it correct.
12-14-2012 04:27 PM
cdminter59
sbc build

I have a question for you. What type of gas do you plan on using in this rat rod. I see you have a problem. You are going to use Vortec heads which are 64cc chamber heads. In your short block measure the distance from the top of the block to the top of the piston at TDC. You probably will have .025. This area from the bottom of the head to the top of the piston at TDC is call Quench. The recommended Quench is .040. So if you have .025 you will need a .015 head gasket. This setup will give you around 10.425 compression ratio which is too high for pump gas. If you use a .040 thick head gasket to bring the compression down the engine probably will ping under load. You need to talk to your machinist and motor assembler. The 12cc dish piston should have been recommended for using Vortec heads.
12-14-2012 04:25 PM
ap72
Quote:
Originally Posted by MouseFink View Post
That is a tough order. A cam that idles rough due to a lot of valve duration and valve overlap usually does not allow the engine to produce much cylinder pressure and torque a low RPM and therefore you need a lower rear gear ratio to bring the engine RPM up quicker. The rougher the idle, the worst that condition will be.

Sealed Power CS-113R, solid flat tappet cam will fill that request. It would have a bad (meaning good) idle and produce good low end torque and high end horsepower. Cam range is from 2000 to 5500 RPM.

Sealed power CS-113R solid lifter camshaft specifications:
228 degrees I / 230 degree E valve duration
110 deg. LSA
.395" I / .401" E valve lift with 1.5:1 rocker arms
.421" I / .428" E valve lift with 1.6:1 rocker arms (350 CI engine)
Use with 9.5:1 to 10.0:1 static compression ratio.
Comp Cams 813-16 solid lifters
Ouch! that is a tiny cam. it'll run on garbage springs and last forever but don't expect spectacular power.

The 401A3 will be a better match for your goals, provided you run good springs. I'd advise supplementing the cam oiling somehow too, either grooving or face oiling lifters.
12-14-2012 04:15 PM
MouseFink That is a tough order. A cam that idles rough due to a lot of valve duration and valve overlap usually does not allow the engine to produce much cylinder pressure and torque a low RPM and therefore you need a lower rear gear ratio to bring the engine RPM up quicker. The rougher the idle, the worst that condition will be.

Sealed Power CS-113R, solid flat tappet cam will fill that request. It would have a bad (meaning good) idle and produce good low end torque and high end horsepower. Cam range is from 2000 to 5500 RPM.

Sealed power CS-113R solid lifter camshaft specifications:
228 degrees I / 230 degree E valve duration
110 deg. LSA
.395" I / .401" E valve lift with 1.5:1 rocker arms
.421" I / .428" E valve lift with 1.6:1 rocker arms (350 CI engine)
Use with 9.5:1 to 10.0:1 static compression ratio.
Comp Cams 813-16 solid lifters
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 05:14 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.