70bigblockdodge
Old Man with a Hat
The 915 will increase compression ratio but to get a actual number you need to cc and measure how far down in hole the piston is plus gasket volume.
77 440
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bajajoaquin
Senior Member
Which reminded me: I left out gasket thickness in my calculations above. Stock, with 90cc heads, CR 8.3:1; Stealth heads as cast, 8.1:1; Stealth heads milled to 74cc, 9.4:1.
But the main thing is that you seem to be at the point, with cams and heads, and other stuff, that you should stop and think about what you're trying to put together, rather than throwing parts at it. Why don't you give us all the big picture: What parts, what goal, what budget? The guys on this forum are pretty knowledgeable, and can provide a lot of guidance with some more information.
But the main thing is that you seem to be at the point, with cams and heads, and other stuff, that you should stop and think about what you're trying to put together, rather than throwing parts at it. Why don't you give us all the big picture: What parts, what goal, what budget? The guys on this forum are pretty knowledgeable, and can provide a lot of guidance with some more information.
70bigblockdodge
Old Man with a Hat
BTW Newport 440 where ya been did you ever get hump for trans tunnel how is that car wanna sell just kidding welcome back.
moper
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The two best answers thus far IMO:
And:
"But the main thing is that you seem to be at the point, with cams and heads, and other stuff, that you should stop and think about what you're trying to put together, rather than throwing parts at it. Why don't you give us all the big picture: What parts, what goal, what budget? The guys on this forum are pretty knowledgeable, and can provide a lot of guidance with some more information."
There is a lot more misinformation than information floating around on the web. My approach would start with why are you disappointed? What is it not doing for you? What car is it in? What has been done already? There are a few mods that are not bank brakers that will give power, mileage, and driveability but we need to know what issues you're having.
And:
"But the main thing is that you seem to be at the point, with cams and heads, and other stuff, that you should stop and think about what you're trying to put together, rather than throwing parts at it. Why don't you give us all the big picture: What parts, what goal, what budget? The guys on this forum are pretty knowledgeable, and can provide a lot of guidance with some more information."
There is a lot more misinformation than information floating around on the web. My approach would start with why are you disappointed? What is it not doing for you? What car is it in? What has been done already? There are a few mods that are not bank brakers that will give power, mileage, and driveability but we need to know what issues you're having.
newport440
New Member
Oh just been waiting for Spring to get here. The Newport doesn't get the heated under the house garage spot The Road Runner has claimed that spot it's down to bare metal. So too cold to work on the port but I did just get a new wielder so she'll be getting her hump as soon as it warms up. Trying to make some more HP out of the engine that's in it also My buddy's the one who is selling them Stealth heads but I don't think I'm going that route. I'm not sure how much they were milled down and I don't want to get into intake not matching up to the heads. I think I'm gonna get a set of 915 heads for her instead
newport440
New Member
What I'm disappointed in is the lack of power. I have been in 383 cars that ran better than this thing. It's in my 70 Newport with a 4-speed and has a open 3.23 gears. In first gear at the sweet spot of the rpms if you punch it it doesn't even break the tire loose. What I would like is a good 14 sec car. The engine I don't know much about it was a raffle give away engine my dad won back in 83. About 2 years ago we were building a 55 dodge truck and he decided to finally use it when we went to fire it up it just spun over like it had no compression So thinking it was no good we pulled it out and dropped another engine in it. So when I bought my Newport he gave me the engine. I pulled the heads off thinking maybe the rings were lined up or something ? At that point I didn't know what to think then I looked at the pushrods and they were like 1/2 inch longer than stock ? The engine is a 77 block it has a steel crank and what look to be stock pistons. The heads that are on it are 906s. So what I did was install a set of stock pushrods and put it in the port. It seems to run fine carries plenty of oil pressure and doesn't burn any either the idle is pretty loppy but I did put a Hughes thumper cam in it. it says their made for low compression engines. It just doesn't seem to like revving up and if I do drop the clutch to do a burnout which is very important to me lol. it seems to go into valve float very easy. I did not degree the cam but I never have I have put plenty of cams in and built a few engine I'm not a master mechanic but pretty sure everything is install correctly. At this point I just not sure what to do next. That's why I wanted to put some kind of closed chamber heads on it hoping that would help. If you need any other info just ask cause I'm at a lost with it. thanks again for any help with it
bajajoaquin
Senior Member
Have you put a compression gauge on it? It's not the same as measuring and calculating compression ratio, but it will give you some info without pulling the heads.
newport440
New Member
Yeah it was all even but low like 120 / 123 I wonder if the springs are shot this engine sat over 30 years with way too long pushrods in it I was thinking about it last night maybe that's why it seems to valve float so easily when at high rpm ? I have no tach in her so not real sure what it is revving at when this happens
rush
Active Member
I'd put a tach in it and see where your at. I'm thinking somewhere around 45mph would be close to 5500rpms. I'd like to see 150 # of compression. The low compression motors just don't rev like the magnum ones do. I have the same problem watching mine reving they just don't go as fast in a heavy weight.
bajajoaquin
Senior Member
I may be all wet, but it seems to me that at 120 psi, you have bigger problems than throwing on a new set of heads will resolve.
70bigblockdodge
Old Man with a Hat
120 is not that bad you can run crap gas. I have one of those Hughes thumper cams in my challenger I'm not that impressed with it either but it does have great vacuum. You need to find out how far off your timing mark is sounds like you have a timing or fuel problem, my Challenger acted that way it has holes in pick up tube in the tank this problem has slowly gotten worse in the last few years. Also what kind of carb are the plates opening all the way, I know that sounds stupid but I did this with an eddy afb style primaries only opening like 3/4-7/8 making secondaries not even open that far and the counterwieghts hardly opening seemed like forever just to hit 5000 in second, I felt like a idiot for this but when fixed really woke up just some suggestions.
newport440
New Member
It's a 750 afb I had the same carb on my Doba and it ran great. But that something I'll check when I pull her back out. I don't know what to do I got my tax return burning a hole in my pocket lol maybe I'll just put my 4.56 gears in her and buy some NOS. That will wake her up or blow her up haha.
rush
Active Member
What type of ignition are you running? I started my timing at 16 btc and ended up at 12 to run premium fuel. You can here mine ping at idle when you let the clutch out and if I take more timing out of it, it will stall when I turn the air on. I thinking if I don't sell it this year the motor is coming out and apart for some serious upgrades.
moper
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A '70 440 stick Newport? LOVE IT! My #1 favorite of all time car was my '71 4dr Newport. It had a 383 w/NOS when I was driving it, but I was well into a 440+6 4sp conversion when I was forced to get rid of it.
Anyway - you have no cylinder pressure if it's 120psi. So I think you have a few things you need to check. First - a '77 would not have had 906 heads and those heads may have been milled affecting wha tthe previous owner ran for pushrods. The function of the pushrod in a shaft application is to properly give preload to the lifter, and move when the lifter tells it to. So if you changed the length you may have removed any extra length in terms of removing any valves hanging open, but it might not be "right" in terms of preload. In order to check preload the intake & bathtub have to come off. I would also say if you did not degree the cam when it was installed - that could also be a problem. 120psi tells me the cam timing might be retarded. Last - the valve springs for Hughes and Lunatis are ususally pretty heavy for the given cam. You will want to make sure the psrings you have are at least equal to what hughes recommends. My guess is they are less pressure which is compounding the lack of rpm capability. I am not a fan of Hughes cams, or of any cams that are being marketed for a certain type of sound. It's like saying a truck going down the highway in New York is headed west because it has a big "WEST" on the side of the trailer. You have a heavy car, with a mild gear, and no convertor to help. You don't need sound, you need torque. So I'd advise you to degree the cam, and then look carefully into the timing curve you have (and ignition), and then plan to work on the carb. I don't see any huge parts mismatches aside from potentially the valve springs - but you gotta do more than screw it together.
Anyway - you have no cylinder pressure if it's 120psi. So I think you have a few things you need to check. First - a '77 would not have had 906 heads and those heads may have been milled affecting wha tthe previous owner ran for pushrods. The function of the pushrod in a shaft application is to properly give preload to the lifter, and move when the lifter tells it to. So if you changed the length you may have removed any extra length in terms of removing any valves hanging open, but it might not be "right" in terms of preload. In order to check preload the intake & bathtub have to come off. I would also say if you did not degree the cam when it was installed - that could also be a problem. 120psi tells me the cam timing might be retarded. Last - the valve springs for Hughes and Lunatis are ususally pretty heavy for the given cam. You will want to make sure the psrings you have are at least equal to what hughes recommends. My guess is they are less pressure which is compounding the lack of rpm capability. I am not a fan of Hughes cams, or of any cams that are being marketed for a certain type of sound. It's like saying a truck going down the highway in New York is headed west because it has a big "WEST" on the side of the trailer. You have a heavy car, with a mild gear, and no convertor to help. You don't need sound, you need torque. So I'd advise you to degree the cam, and then look carefully into the timing curve you have (and ignition), and then plan to work on the carb. I don't see any huge parts mismatches aside from potentially the valve springs - but you gotta do more than screw it together.
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