Chevelle with 307 - Page 2 - Chevelle Tech
Engine General Engine Discussion.

 10Likes
Reply
 
LinkBack Thread Tools Search this Thread Display Modes
post #16 of 26 (permalink) Old Dec 3rd, 19, 11:19 AM
blm
Lifetime Premium Member
Brad
 
Join Date: Sep 2002
Location: McDonald Pennsylvania
Posts: 11,296
Garage
Re: Chevelle with 307

Quote:
Originally Posted by s1nemesis1s View Post

Where is a good place to look for 454's
Craigslist, junkyards, any place that has broken down RVs.
shovelrick and s1nemesis1s like this.
blm is offline  
Sponsored Links
Advertisement
 
post #17 of 26 (permalink) Old Dec 9th, 19, 8:47 PM
Tech Team
 
Join Date: Nov 2019
Posts: 193
Quote:
Originally Posted by blm View Post
Craigslist, junkyards, any place that has broken down RVs.
What model years would be good to look at? I see a ton with fuel injection going all the way up into the 90s. Guess what I am asking, what years/models would be good to pull this big 454 girl from?
s1nemesis1s is offline  
post #18 of 26 (permalink) Old Dec 9th, 19, 10:11 PM
Lifetime Premium Member
Tom
 
Join Date: Oct 2006
Location: Firestone, CO
Posts: 1,436
Re: Chevelle with 307

I prefer the mark IV engines. '73- early '90s in trucks and motorhomes. Look for 959, 445 and 289 block castings. The mark V blocks don't have fuel pump provisions.
s1nemesis1s likes this.

70 Camino...Roller

69 Malibu Stock 307, Reverse Manual TH350, 4,500 Stall Edge Converter, 4.56 Spool 35 Spline 12 Bolt

76 C20 VortecPro 496 628HP 655 lb/ft TH400 Edge Converter, 4.10 14 bolt
Tommy the Cat is offline  
 
post #19 of 26 (permalink) Old Dec 11th, 19, 9:46 PM Thread Starter
 
Join Date: Jul 2018
Posts: 24
Re: Chevelle with 307

Quote:
Originally Posted by blm View Post
I say skip the 350 and go straight to the 454. Way more potential for power and more common than the 396. They can be found in big cars, pickups, motor homes, etc.
While it's a good idea I don't think it's as simple as it sounds. Is there any difference in wiring, motor mounts,accessory brackets, pulleys,or any balancing issues? And the exhaust, which is new by the way, or doesn't the suspension need work to support the extra weight of the BBC. And to an old dude like me a cam change in a SBC looks like a hell of a lot of work!

Dave
s1nemesis1s likes this.
D Berry is offline  
post #20 of 26 (permalink) Old Dec 12th, 19, 7:44 AM
blm
Lifetime Premium Member
Brad
 
Join Date: Sep 2002
Location: McDonald Pennsylvania
Posts: 11,296
Garage
Re: Chevelle with 307

Quote:
Originally Posted by D Berry View Post
I might consider a 396 too.

Dave
Quote:
Originally Posted by D Berry View Post
While it's a good idea I don't think it's as simple as it sounds. Is there any difference in wiring, motor mounts,accessory brackets, pulleys,or any balancing issues? And the exhaust, which is new by the way, or doesn't the suspension need work to support the extra weight of the BBC. And to an old dude like me a cam change in a SBC looks like a hell of a lot of work!

Dave
Well Dave,
Some of those things you will have to deal with however if you are considering a 396 you will have to overcome the same issues.
blm is offline  
post #21 of 26 (permalink) Old Dec 13th, 19, 9:14 AM
Lifetime Premium Member
Jesse
 
Join Date: Dec 2007
Location: W Central Illinois
Posts: 439
Garage
Dave, where in Illinois are you? I could hook you up.

Jesse
6426yy is offline  
post #22 of 26 (permalink) Old Dec 13th, 19, 12:35 PM
Team Member
Bill
 
Join Date: Jan 2018
Location: Boston Area
Posts: 1,116
Garage
Re: Chevelle with 307

I dropped a set of 194 fuelies on my 69 Camaro 307 with 3 on the tree. While I had it apart I installed a L79 Cam (222/[email protected] .447 lift) cast iron intake with a Quadrajet and a decent exhaust and it certainly woke it up big time. My current L79 has 64 cc 202 double hump fuelies with 11 to 1 forged pistons and it doesn't ping on 93 octane. I am using a .39 compressed head gasket which brings it down below 10.5 to 1. Everyone hates the 307's but they can be a fun little engine with a few low cost upgrades. Headers would also be nice but I didn't go that route on mine. I would guess your final compression with 64 cc heads would be around 9.5 to one. I would redo the compression check with the throttle open and with and without oil in the cylinders and record your findings. You should be higher then 125 compression IMO.
s1nemesis1s likes this.
Billdini is offline  
post #23 of 26 (permalink) Old Dec 15th, 19, 9:26 PM Thread Starter
 
Join Date: Jul 2018
Posts: 24
Re: Chevelle with 307

Quote:
Originally Posted by 6426yy View Post
Dave, where in Illinois are you? I could hook you up.

I'm located between St Louis and Quincy but I'm not looking to perform an engine swap, at least not to a big block anytime soon, I was really just thinking out loud. The whole thread sort of went off track, although not without my participation. And I still don't really know how much cylinder pressure a 10 to 1 engine should have and how that would be figured, there must be some way to figure it out. And then there is Dynamic Compression Ratio which is another kettle of fish.

Dave
D Berry is offline  
post #24 of 26 (permalink) Old Dec 16th, 19, 10:43 AM
Senior Tech Team
jeff
 
Join Date: Jan 2008
Location: yukon ok.
Posts: 5,224
Re: Chevelle with 307

You can get close to figuring cranking pressure but it really does not matter one little bit neither does dynamic compression or actual compression.
I say that above when it comes to running a certain octane fuel or a certain timing curve.


I have a 10.0 compression Toyota and it runs best on 87 octane as did my 10.5 compression Honda that revved to 12,200 rpm. (motorcycle)
I built a 350 with 54cc double humps .028 piston to head clearance 41 total timing it loved 93 octane. Compression was 11.98 270H comp magnum cam Yea dynamic was very high.
245 psi cranking pressure.
Lots of little things made it work. I pulled loaded trailers and my boat with it often.
91 octane and I would run 38-39 total timing.

I added 64cc double humps to it much later and had less cranking pressure 185 psi and it did not like near as much timing and I had to slow the curve down. heads were ported the same way.

I have seen 180 psi cranking pressure small blocks that would not run on pump gas even if you pulled timing to 28 total.

My current 350 has 10.87 compression and 57cc heads, it has had the small 268H and 280h cam in it currently.
91 octane is used but if I can only find 87 it runs fine.. just do not load up the engine or it will ping unless you pull timing.

I have found in many years of running high compression that surface texture in the intake runners and ports and chamber shape play a huge role in what kind of compression an engine can tolerate on what octane fuel.

I have also had 8.5 compression engines that had 200 psi cranking pressure and ran on 87 for 376,000 miles.
Little cam that was done at 4200rpm.
That was a 200" Ford inline 6.

Something that makes a huge difference in cranking pressure is cranking speed (RPM)

Stick a 1/2 dead battery into the car and check cranking pressure. you may be lucky to get 80 psi from something that would normally make 200+.
Hook it up to a good 18 volts and test cranking pressure that 200 psi may check in at 280 due to higher RPM.

I messed up a compression tester when I was younger.. it was only 18 bucks, I thought I would be smart and remove 1 spark plug and teat that hole with the engine running.

The gauge spiked instantly to 300 PSI and killed it.
Too much RPM, 850 rpm is what that was at idle.

A different starter that cranks the engine faster will make the reading higher.

Experience and hands on testing things is the best way too see what you can and can't get by with.

Maybe I can run higher compression than most because my old school iron heads only flow in the 220-250 cfm range at .500" lift.. so not really packing the cylinders as full as a head flowing 280 cfm.

I do not know i have not tested that aspect.
jeff swisher is offline  
post #25 of 26 (permalink) Old Dec 16th, 19, 2:56 PM
Senior Tech Team
 
Join Date: Feb 2019
Posts: 1,135
Re: Chevelle with 307

A fat lower lift flow head will make more power that a head that has big flow numbers at the top lift IE: .600 to .700 lift range as to get the big numbers you have to give it up somewhere. My last set of Vortec heads flow at .450 lift was close to 240ish range and heads are at a lift point 2 times opening and closing and only at peak lift once, so that big number is just that, a big number in my book.
68Chevele is offline  
post #26 of 26 (permalink) Old Dec 17th, 19, 5:26 PM Thread Starter
 
Join Date: Jul 2018
Posts: 24
Re: Chevelle with 307

Great post Jeff, I didn't quote it cause it's so long. There are so many factors that can affect pinging that it requires a lot of thought, research, and a little luck to figure. I think I'm probably going to have to stick with what I have, except for a 260 cam and maybe a TH350. It doesn't take to long for a Powerglide to lose its novelty.

Dave
D Berry is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Chevelle 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, you will be sent a confirmation request to this address.

Email Address:
OR

Log-in










Thread Tools Search this Thread
Show Printable Version Show Printable Version
Email this Page Email this Page
Search this Thread:

Advanced Search
Display Modes
Linear Mode Linear Mode



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

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