383 build
#2045283
04/03/16 01:49 PM
04/03/16 01:49 PM
|
Joined: Feb 2011
Posts: 930 Campbellsport, Wisconsin
Abodysforever
OP
super stock
|
OP
super stock
Joined: Feb 2011
Posts: 930
Campbellsport, Wisconsin
|
I am helping a friend of mine doing a upgrade on his 68 Road Runner he just purchased. Its stock except for headers and a M1 duel plane intake,Edelbrock carb. It idles smooth,not like a muscle car. Its a 4speed car,even has the Inland shifter yet. He wants a cam upgrade,poss head work to give it more of a muscle car feel,and better acceleration. He is on a budget ao he is not looking at pulling the motor,juat head work cam upgrade,something with a nice thumping idle,ideas?
|
|
|
Re: 383 build
[Re: Abodysforever]
#2045294
04/03/16 01:55 PM
04/03/16 01:55 PM
|
Joined: Jan 2003
Posts: 14,514 So. Burlington, Vt.
fast68plymouth
I Live Here
|
I Live Here
Joined: Jan 2003
Posts: 14,514
So. Burlington, Vt.
|
Step 1: determine your budget
There are a couple of similar recent threads........ Do a search, there's some good info in those threads.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
|
|
|
Re: 383 build
[Re: Abodysforever]
#2045297
04/03/16 01:57 PM
04/03/16 01:57 PM
|
Joined: Dec 2007
Posts: 77 British Columbia Canada
Challenger340
member
|
member
Joined: Dec 2007
Posts: 77
British Columbia Canada
|
Has the engine been rebuilt prior in it's history ? The reason I ask is because "rebuilder" Pistons for 383's can be notoriously lacking in any compression ratio to work with ? just say'in.... it would be very nice to know what Pistons are present in the 383 before attempting a plan in Camshaft & Heads ?
Better to be a "has been" than a "never was".
|
|
|
Re: 383 build
[Re: Abodysforever]
#2045344
04/03/16 02:26 PM
04/03/16 02:26 PM
|
Joined: Jan 2003
Posts: 14,514 So. Burlington, Vt.
fast68plymouth
I Live Here
|
I Live Here
Joined: Jan 2003
Posts: 14,514
So. Burlington, Vt.
|
It all starts with the cam choice. Everything else follows to match the cam. Interestingly, I do it the opposite way. I determine all the other pertinent items I plan on using for the package, then use the cam to help tie it all together. For me, the cam is basically the last thing I chose.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
|
|
|
Re: 383 build
[Re: Abodysforever]
#2045385
04/03/16 02:51 PM
04/03/16 02:51 PM
|
Joined: Feb 2011
Posts: 930 Campbellsport, Wisconsin
Abodysforever
OP
super stock
|
OP
super stock
Joined: Feb 2011
Posts: 930
Campbellsport, Wisconsin
|
I should of said its running 3.55 gears. The previous owner said it had a bone stock rebuild with the exception of intake amd headers. This engine idles like a Imperial its so smooth. He wants a little attitude in it. Maybe stealth heads or a mild port,polish on the stock 906 heads.
He is going with a MP electronic ignition conversation also.
Last edited by Abodysforever; 04/03/16 02:54 PM.
|
|
|
Re: 383 build
[Re: fast68plymouth]
#2045386
04/03/16 02:51 PM
04/03/16 02:51 PM
|
Joined: Dec 2007
Posts: 77 British Columbia Canada
Challenger340
member
|
member
Joined: Dec 2007
Posts: 77
British Columbia Canada
|
It all starts with the cam choice. Everything else follows to match the cam. Interestingly, I do it the opposite way. I determine all the other pertinent items I plan on using for the package, then use the cam to help tie it all together. For me, the cam is basically the last thing I chose. Yeah, I think Dwayne has the right idea here ? Figure out what ya got to work with ?... then come up with the Cam to best fit and make it work.
Better to be a "has been" than a "never was".
|
|
|
Re: 383 build
[Re: Abodysforever]
#2045398
04/03/16 03:00 PM
04/03/16 03:00 PM
|
Joined: Jan 2003
Posts: 14,514 So. Burlington, Vt.
fast68plymouth
I Live Here
|
I Live Here
Joined: Jan 2003
Posts: 14,514
So. Burlington, Vt.
|
To Russ's point, I don't know if correct height 1968/69 hp 383 pistons were ever available. I've never taken apart an original 68/69 hp 383....... Did those motors actually have positive deck height pistons as delivered from the factory?
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
|
|
|
Re: 383 build
[Re: fast68plymouth]
#2045418
04/03/16 03:18 PM
04/03/16 03:18 PM
|
Joined: Dec 2007
Posts: 77 British Columbia Canada
Challenger340
member
|
member
Joined: Dec 2007
Posts: 77
British Columbia Canada
|
To Russ's point, I don't know if correct height 1968/69 hp 383 pistons were ever available. I've never taken apart an original 68/69 hp 383....... Did those motors actually have positive deck height pistons as delivered from the factory? I took a few apart in my teens back in the 70's, and I twern't smart enough to actually measure much past a ruler ? LOL, but seems to me from memory... if they weren't "positive", they were pretty darn close to, or at "zero" anyways ?
Better to be a "has been" than a "never was".
|
|
|
Re: 383 build
[Re: Abodysforever]
#2045445
04/03/16 03:43 PM
04/03/16 03:43 PM
|
Joined: Jan 2003
Posts: 14,514 So. Burlington, Vt.
fast68plymouth
I Live Here
|
I Live Here
Joined: Jan 2003
Posts: 14,514
So. Burlington, Vt.
|
I suspect the "+.020" deck height spec was more for the NHRA than what the actual deck clearance was. Seems like the tallest replacement piston I remember seeing for one of those has a 1.920 CD.
I think many of the rebuilder type pistons are more like the 1.848 CD variety, and some of those have a dish in them to boot.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
|
|
|
Re: 383 build
[Re: Abodysforever]
#2045453
04/03/16 03:52 PM
04/03/16 03:52 PM
|
Joined: Nov 2011
Posts: 2,154 Its a TRAP!
DARTH V8Я
Oh No!! I just had a moron attack!
|
Oh No!! I just had a moron attack!
Joined: Nov 2011
Posts: 2,154
Its a TRAP!
|
If you want a little attitude in the idle fatten up the idle mixtures and set the base timing to like 2-3* BTDC. That'll give it some rumble rumble while idling.
Regarding cam; for me it's choose the cam I want first, then build everything around it.
When it takes more than a sweet mullet to prove you rule at the trailer park..
|
|
|
Re: 383 build
[Re: Abodysforever]
#2045462
04/03/16 03:57 PM
04/03/16 03:57 PM
|
Joined: May 2008
Posts: 5,399 Aurora, Colorado
451Mopar
master
|
master
Joined: May 2008
Posts: 5,399
Aurora, Colorado
|
One issue I had on my 383 was the lack of valve reliefs in the piston. Flat top pistons that appear to be zero deck height. The heads were milled for compression which made the piston to valve clearance issue worse.
Edit: FWIW the pistons in this were sealed power forged replacement HP pistons, but engine built in the 1980's.
Last edited by 451Mopar; 04/03/16 04:10 PM.
|
|
|
Re: 383 build
[Re: fast68plymouth]
#2045471
04/03/16 04:03 PM
04/03/16 04:03 PM
|
Joined: Feb 2005
Posts: 4,319 Prospect, PA
BSB67
master
|
master
Joined: Feb 2005
Posts: 4,319
Prospect, PA
|
Right on the 1.920.
So, for the OP, if it has original pistons, there are some decent options, depending on budget. A 0.040" gasket, your favorite closed chamber head (915, or any of the aluminums out there) then fine tune chamber volume/cam to the best outcome.
|
|
|
Re: 383 build
[Re: Abodysforever]
#2045477
04/03/16 04:05 PM
04/03/16 04:05 PM
|
Joined: Jan 2003
Posts: 14,514 So. Burlington, Vt.
fast68plymouth
I Live Here
|
I Live Here
Joined: Jan 2003
Posts: 14,514
So. Burlington, Vt.
|
At least there are a couple of reasonably priced piston options now to get decent compression, quench, and valve to piston clearance. KB 162 flat top, KB 400 6cc dome. The KB 400 works well with the 84cc edelbrock, sidewinder, stealth type heads.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
|
|
|
Re: 383 build
[Re: 451Mopar]
#2045480
04/03/16 04:07 PM
04/03/16 04:07 PM
|
Joined: Feb 2005
Posts: 4,319 Prospect, PA
BSB67
master
|
master
Joined: Feb 2005
Posts: 4,319
Prospect, PA
|
One issue I had on my 383 was the lack of valve reliefs in the piston. Flat top pistons that appear to be zero deck height. The heads were milled for compression which made the piston to valve clearance issue worse. Presuming typical streeter kind of a deal, he should be okay with some cam options. But you do make an important point that needs to be in the equation.
|
|
|
Re: 383 build
[Re: BSB67]
#2045481
04/03/16 04:07 PM
04/03/16 04:07 PM
|
Joined: Jan 2003
Posts: 14,514 So. Burlington, Vt.
fast68plymouth
I Live Here
|
I Live Here
Joined: Jan 2003
Posts: 14,514
So. Burlington, Vt.
|
Right on the 1.920.
So, for the OP, if it has original pistons, there are some decent options, depending on budget. A 0.040" gasket, your favorite closed chamber head (915, or any of the aluminums out there) then fine tune chamber volume/cam to the best outcome. And if it has the typical rebuilder variety...... It's time for the hard decisions. Using a 1.848 flat top in an uncut block with a steel shim gasket and the normal 88cc open chamber head, puts you in the 8.0 cr range. That's going to limit how much cam you really want to stuff in there.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
|
|
|
Re: 383 build
[Re: fast68plymouth]
#2045488
04/03/16 04:15 PM
04/03/16 04:15 PM
|
Joined: Feb 2005
Posts: 4,319 Prospect, PA
BSB67
master
|
master
Joined: Feb 2005
Posts: 4,319
Prospect, PA
|
Maybe I'm missing it, but I thought that the dome/reliefs on the KB 400's were a wash, and they end up with low 9:1 with an 84 cc head and no quench w/o a bunch of milling.
Last edited by BSB67; 04/03/16 04:16 PM.
|
|
|
Re: 383 build
[Re: Abodysforever]
#2045495
04/03/16 04:20 PM
04/03/16 04:20 PM
|
Joined: Jan 2003
Posts: 14,514 So. Burlington, Vt.
fast68plymouth
I Live Here
|
I Live Here
Joined: Jan 2003
Posts: 14,514
So. Burlington, Vt.
|
I get about 9.9:1 with a KB 400, down the hole .024(stock deck height), .022 gasket and an 84cc head.
The KB 400 is listed as having 6cc effective dome volume. If the dome and the reliefs were a wash it would be listed as a 0cc dome.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
|
|
|
|
|