My Motor Build up. 383

[condor74]

Hello first I want to say hi as I am new to this website.

I am getting ready to assemble my 383 and thought I get your opinions on the build.

Ok here we go. I have a 1968 Plymouth Sport Satellite. It is rough but mostly there. The motor is a 1968 383 bored .060 over. The pistons are older Chrysler part number 11 to 1 forged pistons. The rods are stock. The crank is stock. The heads right now at least are 906 casting ...Right now they are stock but I plan to port and port match them. The cam I am using is a Mopar Purple hydrolic cam .509 lift. I don't have the other specs in front of me. Intake manifold is a tried and true aluminum Holley Street Dominator. Carburetors that I have now is a 650 Edelbrock and a 750 dual feed Vac secondary Holley. I have a Mallory Dual point distributor also in it. I also have a Mopar performance windage tray and high volume pump.

The rest of the car is set up with a 727 torqueflight, The car has an old 3000 rpm stall converter made by GER that has been in there for the past teen years. It has a Turboaction Reverse manual Valve body. The rear axle is an 8.75 rear axle with 3.9 to 1 gear ratio. It has 275 60 r 15 rear tires for the street and a set of 26x 10 slicks for the track. It has skinny front tires.

What do you think this will run...Any advise. With the exception of the Reverse valve body and the new motor everything else has been run on the car with the old 383 which was a stock 2bbl 383 with the same size cam and intake carb combo. It ran really strong on the street but never have taken down the track. Unfortunately the old 383 spun number 1 and 2 rod bearings.

thanks for your opinions.
Alan

 

[Bens69PlymouthSatellite]

Cant say what that car will run,I would say replace the bottom end w/ after market rods and use the 650 carb.What compression is the engine actually at? are you trying to stay w/ pump gas? What CC are the heads?

 

[Meep-Meep]

If you have an honest 11:1 CR that will make the .509" cam quite happy, but don't forget the race gas. 650 CFM should be enough but the 750 vac can work well too. All in all your combo sounds good (you can use more gear for drag racing) but should still work OK with the 3.91's. My GUESS is you should be in the high 12's at about 107-110 MPH if you can hook it up. Low 13's blazing the tires.

 

[Redhorse719]

Welcome to the site.

 

[wingcarenvy]

Welcome, Your combo sounds pretty good. Some of the things to consider is the 11 to 1 compression ratio is too high for 91 octane we have here on the west coast. 10 to 1 is doable if the cam has a lot of over lap. The good news is that 11 to 1 pistons are rarely 11 to 1 they are more like 10.3 to 1. Couple this with your cam choice, you can run pump gas but will have to be conservative on the timing and have the motor run very cool like 160 degrees. Stock rods will be way more than strong enough for your power level. As far as the carb is concerned, I would run a 750 DP as a minimum. I would even say an 850 will work good too. Probably an 800 DP would be perfect. I say it will go 107 in the quarter which will vary depending on chassis which you seem to have some goodies that will let it ET pretty well, my guess mid 12s. Good luck I bet it will sound awesome!

 

[q-ship]

A true 11:1 compression with a 509 cam is about perfect from a cylinder pressure standpoint for 91 octane, which calculates out to just over 150 psi.

cylinder pressure will rise quite a bit with that cam as RPM increases , but should still be quite workable with 91 if you don't have the timing coming "all in" to quickly.

It sounds like a really good "old school" build, and related parts selection, to me.

P.S. I spent a couple of years in Taft many, many years ago. From a car guy standpoint, it was great. --- Do you run "drip gas" in any of your cars?

 

[condor74]

Thanks for all the replies. I am not sure what drip gas is. I know the 11 to 1 is really pushing it on pump gas but they are the pistons I have. I also picked up a set of .080 thick copper head gaskets. I am hesitant to run these on the street as I have heard that copper is hard to get to seal around the oil and coolant passages. I also have to O ring the block to run them. I figure I will give the normal felpro gaskets a shot and see if i can run it by taking some of the timing out of it. That would be nice in the fact that if i really want to set the engine on kill I can buck up and buy some race gas and dial the timing back into it. I think I am going to hold on to the copper gaskets and use them if I cant manage it on pump gas at all.

Does anyone have any opinions on running octane booster. Does it actually work? Is it just snake oil? Also I was considering aviation fuel. I can get high octane fuel there but I know it is formulated to burn at 20000 feet and not at see level.

If i hook and run mid 12s I will be happy with that. I also just purchased a Turbo Action reverse manual valve body. I might look into some steeper gears..Thinking something in the 4.56 to 4.88 range ...It will be miserable to drive on the highway but fun in the 1/4 mile.

 

[condor74]

I was down at the machine shop today talking to my machinist. We were discussing the piston to cylinder wall clearance for these walls and he was asking me what I would like him to set it at. I called Mopar Performance Tech line as my pistons are old direct connection pieces. He said they are made by TRW and Chrysler put there part number on them. He said the spec on the clearance is .006 to .007 with some racers running them as much as .010. I decided to go on the high side of spec. so .007 is what we are going with. Tonight I am grinding the casting flash off the connecting rods which is supposed to stress relieve them.. I am getting actous to put this togeather.

 

[Cranky]

I run those at .005 and taking the casting flash off does not stress relieve them. What it does do is it takes off the 'extended' metal off the beams so when the rod flexes, it won't have a starting place for a crack to begin. Shot peening the rod will stress relieve it.....

 

[condor74]

Stress relieve was the wrong term but yes that is why I plan to get rid of the flash.

 

[Meep-Meep]

I'd be really surprised if you can run CA pump gas with 11:1. Not only is that a lot of compression but the piston dome, as well as temperature of the incoming fuel charge and bore size will play a roll in determining octane requirement. Taking the timing out is not the best way to go but rather keep the full recommended timing curve and reduce the compression to accommodate the fuel. Can you clip and blend the domes a bit? If I were you I'd keep some race gas handy for mixing a special brew. You want to be on the verge of detonation for peak efficiency.

I have used 1-2 gals of 110 Sunoco to 12-14 gals of 91. I also used octane booster and it does work but I think you have to strike when the iron is hot so to speak. Meaning, a few minutes after I put it in I had good power without detonation but letting it sit overnight before racing it pinged all the way down the track. I understand it's oil based and have heard it can separate but that tank was being mixed on the trailer for 60 miles before arriving at the track. Like I said, many factors involved. I suppose you will find out what it wants soon enough, and when you do we want to know!

 

[72Satellite440]

Welcome to the site. Your build sounds like its coming along

 

[condor74]

I picked up some new pieces this weekend..I am not sure if i am going to use them. I have a set of aluminum roller tip rocker arms. I am not sure of the brand as they are used. They came with the hardened rocker shafts also and 4 extra rocker arms. I googled the part number that is on them and they came up on here as cats motor parts...I was told they were originally sold out of 440source as there house brand. They are 1.5 ratio and for the most part seem to be in good condition. I found a few roller bearings on a couple of them that feel rough. I was considering finding the bearing supplier and just ordering me enough bearings to replace them all but they are 5 dollars a bearing and for 2 bearigns a rocker arm with 16 rocker arms...that comes in at 32 bearings and about 160 dollars. i also thought of making brass bushings for the rocker arms to ride on instead of he needle bearings...that way less chance for them to fail and send parts into the engine. The rocker shafts are drilled and pressure feed oil to the rocker arm locations so feeding oil ot a brass bushing shouldn't be a problem...Or is any of this even worth the benefit of running the dang things? The roller part of the tip seems to be in good shape on all of them.. What do you think...

As far as the rest of the engine. I am waiting for my rods to get done being resized after i had ARP rod bolts installed. I also got ARP main bolts. My machinist is letting me help him in the machine shop so I am actually learning a lot about the procedures for that part of it...I have been an auto technician in a Dodge dealership for more than 15 years but it is fun to get in and actually do the machine work also. this week we are trueing up the decks on the block and doing the boring. He uses a boring bar that actually bolts to the deck of the block. Then we will be honing it after all that...We are setting the piston to cylinder wall clearance at .007 ... For older design forged pistons.

 

[condor74]

I am thinking of just selling the roller rocker arms now. I know I could bush them and if i keep them I might eventually do that, but it seems like a lot of work for getting a set of 1.5 ratio rocker arms to work. the factory arms are reliable, light, and are already there. I read some horror stories of people using cheep roller rockers and having the roller bearings seize on the shaft holding a valve open and tagging a valve with a piston. I also know that some of these rocker arms already are showing bearing problems...So my feeling is that if I put in new bearings and they fail later then it is just a design problem..Bushing the rocker arms would work but I think it would just be better to sell them and run the stockers until i have enough dough to buy a more expensive higher quality set.

 

[Meep-Meep]

As far as rockers go you would be fine with the iron adjustables from Crane or Isky. This is what I run together with 3/8" push rods and never an issue. If you plan on running any kind of decent spring you really should do this upgrade.

 

[condor74]

Ok I have been at the machine shop all this weekend and I hope I avoided a problem. My machinist who is also a good friend of mine wanted to true up the deck. He originally had we torqued the main caps down to 100 foot pounds with the ARP main bolts. He has a large square machine bar that slides through the main bearing bore and sits on a jig on the decking machine. He originally had shimmed up the front of the motor to bring the deck level side to side and for and aft. It took .018 to true the deck. This seemed excessive to me and I started asking questions...It seemed to cut more on the side that was shimmed up as apposed to the other side. I then requested we take the shim out and level the bar the motor is sitting on... verify the machine is level and take another cut so it will keep the deck parallel with the main bearing bore. We did this and managed to get it with out taking hardly any material off of the side that had the heavy cut before. The Deck is now true and in my opinion more parallel to the main bore than he had it. The final amount removed is .0185....Now I want to remove the same amount from the other side. I also was thinking of not re zeroing the machine. In theory that would make sure the cut is exactly the same distance from the main bore as the other side.

My machinist is a very good guy and an old school machinist but I don't think he has a lot of experience with high performance builds as apposed to just a stock rebuild. He is good enough that he will machine what ever I want to my specs.

 

[condor74]

Another update. We have bored the block .060 oversize now. One problem. The number 5 cylinder has not cleaned up completely. there is some pitting from rust that is still visible to the naked eye but I can not feel it at all with my fingernails or my fingers. I still have to hone the block and we will be taking out another .005 to get to the .007 cylinder wall clearance I am looking for with the forged pistons. How deep is a rust pit that you can see but not feel? I am a little anxious about this until I get it honed. If they do not come completely out, should I find another block, sleeve the cylinder, run it and hope for the best. I have heard that it would probably be ok. My feeling is it may be ok on a stock rebuild but with the 11 to 1 compression ratio cylinder pressures will be high and they will find any week link in the cylinder sealing. Other than that everything is coming along well.

 

[Meep-Meep]

I have run engines with small witness marks or a slightly peppered cylinder from rust like you describe all without issues. My boat currently has some peppering in it and I'm not at all concerned. I once built a VW type 1 engine with used pistons, cylinders and rings from two or three different engines and it ran great. I just measured everything carefully and put it together. You'd be surprised how bad things can be and still work.

 

[Cranky]

Guys, angelababy is a freakin spammer!

 

[1968_Roadrunner]

Guys, angelababy is a freakin spammer!

What???