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IF YOU GO TO A CALCULATOR AND USE -6CC AND 0.025 DECK HEIGHT IT COMES OUT TO 10.4:1 W/64cc THROW OUT THE DECK HEIGHT AND ADD IN THE 72cc CHAMBER AND IT COMES TO 10.1:1Quote:
Originally posted by erik erikson
YES,BUT HE USED -4CC IN THE VALVE RELIEF VOLUME.
NOW I AM STARTING TO GET A HEADACHE.I SAY WE TAKE .005 OFF THE DECK AND CALL IT GOOD.JUST KIDDING.YOU BOTH ARE RIGHT.IT DEPENDS IF YOU ROUND UP OR DOWN ON THE NUMBERS.Quote:
Originally posted by camaro_fever68
IF YOU GO TO A CALCULATOR AND USE -6CC AND 0.025 DECK HEIGHT IT COMES OUT TO 10.4:1 W/64cc THROW OUT THE DECK HEIGHT AND ADD IN THE 72cc CHAMBER AND IT COMES TO 10.1:1
4.030 BOREQuote:
Originally posted by erik erikson
YES,BUT HE USED -4CC IN THE VALVE RELIEF VOLUME.
3.750 STROKE
64cc HEAD
0.025 DECK
-4cc RELIEF
0.039 GASKET
EQUALS 10.63:1
4.030 BORE
3.750 STROKE
72cc HEAD
0.000 DECK
-4 RELIEF
0.039 GASKET
EQUAL 10.3:1
I THINK HE SAY F**K THIS HE'LL BUY A BOOK OR GO DROP IT OFF A ENGINE SHOP LOL **) :CRY: :confused: :HMMM:Quote:
Originally posted by dcoffield
So, if I understand what you are saying (before the conversation got 'squishy':LOL: ):
I should get the rotating assembly, fit the crank and a piston to
be able to measure the height of the deck from the piston at TDC.
Should I do this after the block is machined and decked flat?
Then have the deck machined down to 0 when I have the measurement?
I went back and edited my answers here. I must have been really tired when I first answered, cause the answers were wrong.Quote:
Originally posted by techinspector1
"I should get the rotating assembly, fit the crank and a piston to
be able to measure the height of the deck from the piston at TDC"
yes, use a piston/rod assy on each corner, cylinders 1,2,7 and 8, make sure you have the piston at TDC on each cylinder and measure with a depth mic from the block deck to the crown of the piston. The piston will want to rock on the wrist pin, so measure each piston right at the cylinder wall at the pin location, not toward the intake or exhaust side of the motor. Measure at two locations on each piston, at 3 O'clock and 9 O'clock as you stand at the side of the motor. A different reading on the same piston at 3 and 9 will indicate a bent rod.
"Should I do this after the block is machined and decked flat?
Then have the deck machined down to 0 when I have the measurement?"
Edit: The block has to be bored to fit the new pistons.
"Do I need to use the new pistons and crank to check the deck
height?"
yes
"Can this be done before taking the block in to be machined?"
Edit: You must have the 350 block bored at the machine shop in order for you to establish deck with the new pistons. Have it magnafluxed and bored, but not decked yet. Take the block home and check the deck, then if the decks are all out of whack or you want to deck the block to establish squish, disassemble it and take the block back to the machine shop and have them cut the decks to your specs. Or have the machine shop do the whole thing. I answered this incorrectly originally. CRS
The Speed Pro H860CP has these spec according to their web site:
-5 dome volume
1.425 comp distance
530 weight
0.0010 bore clearance
Flat top with 2 reliefs
The pistons are already fitted and the rods are clearanced.
Will I be able to run a standard cam? Isn't that why the rods are clearanced, is for the cam?
I'm thinking I should go with the 72cc heads instead of the 67cc to keep the c r down.
This will be my third engine build. The first 2 were 350's for the circle track race car. Both worked well until we overheaded due to throwing water pump belt. The first one left oil and parts over half the track. The second one got shut off quick enough to keep it all in the oil pan. We haven't got that one out of the car yet to see how bad it is, but I know the cam is busted and 3 or 4 lifters have fallen down. We've started running without power steering to eliminiate that belt (it's the one that goes first and takes out the water pump belt).
Whats involved with clearancing the pan rails? Put the crank in and see where it will hit and then grind it out?
(I've been married 24 years so I am used to filtering out external bickering and useless information, so this conversation doesn't bother me!:o )
You will be able to run a standard camshaft.Quote:
Originally posted by dcoffield
The Speed Pro H860CP has these spec according to their web site:
-5 dome volume
1.425 comp distance
530 weight
0.0010 bore clearance
Flat top with 2 reliefs
The pistons are already fitted and the rods are clearanced.
Will I be able to run a standard cam? Isn't that why the rods are clearanced, is for the cam?
I'm thinking I should go with the 72cc heads instead of the 67cc to keep the c r down.
This will be my third engine build. The first 2 were 350's for the circle track race car. Both worked well until we overheaded due to throwing water pump belt. The first one left oil and parts over half the track. The second one got shut off quick enough to keep it all in the oil pan. We haven't got that one out of the car yet to see how bad it is, but I know the cam is busted and 3 or 4 lifters have fallen down. We've started running without power steering to eliminiate that belt (it's the one that goes first and takes out the water pump belt).
Whats involved with clearancing the pan rails? Put the crank in and see where it will hit and then grind it out?
(I've been married 24 years so I am used to filtering out external bickering and useless information, so this conversation doesn't bother me!:o )
Go with the 72cc heads or run race fuel
You may have to clearance rod to bottom of cylinder
Put the rotating assy together on a dry run rotate engine, If it hits mark it and grind it then do it again till you don't bind anywhere.
LIST OF CLEARANCES TO CHECK:
crank to block .050"
rod to cam .060"
rod to bottom cylinder .60"**)
I just looked closely at the Dart heads I'm considering and they
are 76cc's.
784 cylinder
9 gasket squish
-5 piston dome
76 heads
864 / 80 = 10.8 (did I do that right?)
That's a little high pump gas, isn't it?
Ok, a little help here.......
By the formula stated earlier by tech and 3 different online c r calculator we are around 10.4 to 10.8 give or take...
On the Federal Mogul / Speed Pro web site they say these pistons (H860CP 30) makes 9.21 c r with the 76cc heads.
That's quite a difference, why the difference?
I came up with 9.3:1cr using the measurments:Quote:
Originally posted by dcoffield
Ok, a little help here.......
By the formula stated earlier by tech and 3 different online c r calculator we are around 10.4 to 10.8 give or take...
On the Federal Mogul / Speed Pro web site they say these pistons (H860CP 30) makes 9.21 c r with the 76cc heads.
That's quite a difference, why the difference?
4.030-bore
3.750-stroke
76cc-head
0.039-gasket
0.025-deck height
-5--piston dome
Dart doesn't offer 76cc heads in none of my catalogs
I think my problem was using -5 for piston dome. I should have added 5 in volume not subtracted 5.
That gives me 9.71 on a zero deck.
Here's the link to the heads. I was looking at a 67cc head and that isn't a Dart standard either. I checked with Performance Auto on the 67cc and they said it's correct. I guess they get them special or something.
http://performanceauto.us/store/prod...110264257a025b
A PRO TOP LINE HEAD COMES IN 76 CC'S AND SO DOES THE WORLD PRODUCTS S/R TORQUER HEADS.Quote:
Originally posted by camaro_fever68
I came up with 9.3:1cr using the measurments:
4.030-bore
3.750-stroke
76cc-head
0.039-gasket
0.025-deck height
-5--piston dome
Dart doesn't offer 76cc heads in none of my catalogs
Quote:
Originally posted by erik erikson
A PRO TOP LINE HEAD COMES IN 76 CC'S AND SO DOES THE WORLD PRODUCTS S/R TORQUER HEADS.
DUH!!!! SO DO A MILLION OTHER HEADS, DART DOESN'T THOUGH, THAT SITE HE LEFT A LINK TO REWORKS THE COMBUSTION CHAMBER TO 76cc
THE POINT I WAS TRYING TO MAKE WAS THE PRO TOP LINE HEADS AND THE WORLD PRODUCTS HEADS ARE ABOUT THE SAME SIZE AS THE DART'S AND THEY COME IN 76CC'S.Quote:
Originally posted by camaro_fever68
DUH!!!! SO DO A MILLION OTHER HEADS, DART DOESN'T THOUGH, THAT SITE HE LEFT A LINK TO REWORKS THE COMBUSTION CHAMBER TO 76cc
784 cc's in the cylinder, 76 cc's in the head, 8.43 cc's in the gasket (4.100" gasket bore x 0.039" compressed), 5 cc's in the reliefs and a zero deck will yield 9.76:1 c.r.
With less static compression ratio by using a 76 cc head, you can lighten up on the cam a little and have more bottom end in the motor with maybe a little less converter.
I checked out them heads and that company sort of modifies'em a little bit. Nothing at all wrong with that. They will work great. I did the computations with your CH on your pistons and you can bring your block and pistons to the machine shop and get to clean check bore torque plate hone and deck to 9.0 parallel to the mains. Use fel-pro hi-perf. head gasket and your good to go. You miight have some minor clearancing like I mentioned earlier. I came up with 9.8 on the compression though. When you Zero deck it make sure you use pre-flattened felpro 0.039 gaskets.**)Quote:
Originally posted by dcoffield
I think my problem was using -5 for piston dome. I should have added 5 in volume not subtracted 5.
That gives me 9.71 on a zero deck.
Here's the link to the heads. I was looking at a 67cc head and that isn't a Dart standard either. I checked with Performance Auto on the 67cc and they said it's correct. I guess they get them special or something.
http://performanceauto.us/store/prod...110264257a025b
Tech,Quote:
Originally posted by techinspector1
784 cc's in the cylinder, 76 cc's in the head, 8.43 cc's in the gasket (4.100" gasket bore x 0.039" compressed), 5 cc's in the reliefs and a zero deck will yield 9.76:1 c.r.
With less static compression ratio by using a 76 cc head, you can lighten up on the cam a little and have more bottom end in the motor with maybe a little less converter.
I know you can under compression a motor with a big cam and totally kill the engine. (over camming) I know if you match the compression to the cam pretty good, you won't lose a lot of bottom end.
What I don't understand is your point on if you got a high CR you got to run a big cam. Are you trying to bleed off cylinder pressure, if so why? In my experience a short cam and 9-10.5 CR makes for a stout low-end torque monstor. What are the negatives your trying to avoid.
I try to build my street engines to have 200psi cranking pressure. Anything less is over cammed, I have built 220psi cranking pressure engines with good quench with no problems. This blower motor I'm running now only got 170psi because when I got the blower I changed my order on the pistons to 9.0 instead of 10. And my cam is long 248/258 @0.050
I don't see why I couldn't have a 10.0:CR and a stock cam. It would be more efficient. Especially at cruise because of VE figures.
I'm not going against you, just want to know your reasoning.
YOU DON'T KNOW WHY YOU WOULD WANT TO (BLEED OFF CYLINDER PRESSURE).I THOUGHT SOMEONE LIKE YOU WOULD UNDERSTAND THAT SIMPLE A CONCEPT.DUH!!!Quote:
Originally posted by camaro_fever68
Tech,
I know you can under compression a motor with a big cam and totally kill the engine. (over camming) I know if you match the compression to the cam pretty good, you won't lose a lot of bottom end.
What I don't understand is your point on if you got a high CR you got to run a big cam. Are you trying to bleed off cylinder pressure, if so why? In my experience a short cam and 9-10.5 CR makes for a stout low-end torque monstor. What are the negatives your trying to avoid.
I try to build my street engines to have 200psi cranking pressure. Anything less is over cammed, I have built 220psi cranking pressure engines with good quench with no problems. This blower motor I'm running now only got 170psi because when I got the blower I changed my order on the pistons to 9.0 instead of 10.
I don't see why I couldn't have a 10.0:CR and a stock cam. It would be more efficient. Especially at cruise because of VE figures.
S
I'm not going against you, just want to know your reasoning.
I AM CONVINCED THAT YOU HAVE NEVER BUILT AN ENGINE ANYWHERES BUT ON PAPER. THERE IS NO REASON TO BLEED OFF CYLINDER PRESSURE UNLESS HE WOULD'VE HAD ABOUT 10.5:1 OR MORE COMPRESSION SO HE COULD RUN PUMP GAS. I THINK YOU READ TOO MUCH. PLENTY BOOK IDEAS, NO REAL WORLD EXPERIENCE. HE HAS A 270H CAM FOR THAT ENGINE HE BUILDING AND IT WILL RUN GREAT WITH A GOOD QUENCH ALL THE WAY TO ABOUT 10.3:1 AND HAVE RIGHT ABOUT 200 PSI CRANKING PRESSURES, ACCORDING TO VE AND CAM SPECS. IF YOU TRY TO FIGURE IT TO SAY I'M WRONG, DON'T FORGET THAT THAT CAM HAS 4 DEGREES ADVANCE GROUND IN IT.:whacked:Quote:
Originally posted by erik erikson
YOU DON'T KNOW WHY YOU WOULD WANT TO (BLEED OFF CYLINDER PRESSURE).I THOUGHT SOMEONE LIKE YOU WOULD UNDERSTAND THAT SIMPLE A CONCEPT.DUH!!!
"What are the negatives your trying to avoid."
Detonation from currently available pump fuels.
I'm impressed with your figures and would be interested in knowing what fuel you're using. I've built a bunch of Chevies, but shoot for around 170 on street motors after talking with cam grinders over the years. Maybe I'm just too conservative, but I have an obligation to err on the side of caution in answering questions on this forum, 'cause I'm spendin' someones else's money.
Tech,Quote:
Originally posted by techinspector1
"What are the negatives your trying to avoid."
Detonation from currently available pump fuels.
I'm impressed with your figures and would be interested in knowing what fuel you're using. I've built a bunch of Chevies, but shoot for around 170 on street motors after talking with cam grinders over the years. Maybe I'm just too conservative, but I have an obligation to err on the side of caution in answering questions on this forum, 'cause I'm spendin' someones else's money.
I only thing I do to be able to run a high cranking pressure is run a good quench area (0-deck height, 0.039 gasket) never a dome, D-shaped inverted dome if possible, polish the combustion chamber to a mirror finish (or as close as possible) a crank case evacuation system so that I don't have the PCV running off intake vacuum and putting impurities in the fuel mixture and I have also found that anti-reversion headers and a free flow exhaust helps some especially when you start getting over 205psi.
I run 93 Exxon and only enough timing as needed. I agree with being conservative when answering other questions. I never thought of it that way and for as long as I've been building engines, I HAVE ALWAYS RUN ON THE JAGGED EDGE OF HI-PERFORMANCE AND DURABILITY. PUSHING THE ENVELOPE WAS PART OF THE FUN....... and I'm not about to tell you I didn't let the smoke out quite a few prematurly through the learning process.
DON'T FOGET THE TIMING CHAIN WILL TAKE THE 4 DEGREES RIGHT BACK OUT OF IT. SSHHHH,DON'T SAY THAT I HAVE (NO REAL WORLD EXPERIENCE).I DON'T WANT THE AERA, AND THE ASE TO HEAR YOU.OH,NO. I CAN HEAR YOU SAYING IT AGAIN. L.O.L.Quote:
Originally posted by camaro_fever68
I AM CONVINCED THAT YOU HAVE NEVER BUILT AN ENGINE ANYWHERES BUT ON PAPER. THERE IS NO REASON TO BLEED OFF CYLINDER PRESSURE UNLESS HE WOULD'VE HAD ABOUT 10.5:1 OR MORE COMPRESSION SO HE COULD RUN PUMP GAS. I THINK YOU READ TOO MUCH. PLENTY BOOK IDEAS, NO REAL WORLD EXPERIENCE. HE HAS A 270H CAM FOR THAT ENGINE HE BUILDING AND IT WILL RUN GREAT WITH A GOOD QUENCH ALL THE WAY TO ABOUT 10.3:1 AND HAVE RIGHT ABOUT 200 PSI CRANKING PRESSURES, ACCORDING TO VE AND CAM SPECS. IF YOU TRY TO FIGURE IT TO SAY I'M WRONG, DON'T FORGET THAT THAT CAM HAS 4 DEGREES ADVANCE GROUND IN IT.:whacked:
MY BAD.....I QUIT.....TRUCE.......Quote:
Originally posted by erik erikson
DON'T FOGET THE TIMING CHAIN WILL TAKE THE 4 DEGREES RIGHT BACK OUT OF IT. SSHHHH,DON'T SAY THAT I HAVE (NO REAL WORLD EXPERIENCE).I DON'T WANT THE AERA, AND THE ASE TO HEAR YOU.OH,NO. I CAN HEAR YOU SAYING IT AGAIN. L.O.L.
O.K.,TRUCE.IN SOME AREA'S WE THINK A LIKE,AND SOME WE THINK DIFFRENT.EITHER WAY YOU HAVE A VERY GOOD WORKING UNDERSTANDING OF THE SMALL BLOCK CHEVY.Quote:
Originally posted by camaro_fever68
MY BAD.....I QUIT.....TRUCE.......
A little bit of controversy is ok sometimes because it opens up new and different ideas. It can be healthy if it doesn't get out of hand. You have some good advice about a lot of things and a good understanding also. Heck no-telling what we could come up with if we put our heads together. lol:HMMM:Quote:
Originally posted by erik erikson
O.K.,TRUCE.IN SOME AREA'S WE THINK A LIKE,AND SOME WE THINK DIFFRENT.EITHER WAY YOU HAVE A VERY GOOD WORKING UNDERSTANDING OF THE SMALL BLOCK CHEVY.
I just got the Dart Iron Eagle SS's I ordered...
Sweet
Nice looking, too. A lot finer casting grain than stock.
The ports look to match my gaskets pretty closely.
Now I needs a set of old 2.02 valves to start polishing the bowl.
Any advise on putting on the studs and lifter guides?
DON'T TORQUE DOWN THE STUDS UNTIL YOU HAVE YOUR HEADS ON THE ENGINE.YOU MUST CHECK YOU PUSH ROD ALIGNMENT WITH YOUR ROCKER ARMS.YOU MIGHT HAVE TO GRIND THE HOLES IN THE GUIDE PLATES TO MOVE THEM AROUND ON THE STUDS.MAKE SURE YOU USE HARDENDED PUSH RODS WITH THE GUIDE PLATES.Quote:
Originally posted by dcoffield
I just got the Dart Iron Eagle SS's I ordered...
Sweet
Nice looking, too. A lot finer casting grain than stock.
The ports look to match my gaskets pretty closely.
Now I needs a set of old 2.02 valves to start polishing the bowl.
Any advise on putting on the studs and lifter guides?
There's something that needs clarification here before you ruin a set of guide plates. When Erik said you might have to grind the holes in the guide plates, he meant the hole where the stud goes through to hold them onto the head, not the slots where the pushrods ride. Sometimes you have to re-manufacture parts that you buy to make them work right. You may have understood, but I just want to make sure. Also, the plates are hardened, so you can't drill them. That's why Erik said "grind". Best way is a small round stone in a die grinder or in an electric drill motor if you don't have a grinder and air to run it.Quote:
Originally posted by erik erikson
DON'T TORQUE DOWN THE STUDS UNTIL YOU HAVE YOUR HEADS ON THE ENGINE.YOU MUST CHECK YOU PUSH ROD ALIGNMENT WITH YOUR ROCKER ARMS.YOU MIGHT HAVE TO GRIND THE HOLES IN THE GUIDE PLATES TO MOVE THEM AROUND ON THE STUDS.MAKE SURE YOU USE HARDENDED PUSH RODS WITH THE GUIDE PLATES.
If you plan to use stamped rockers, check for clearance where they pivot on the stud through the entire lift of the valve. Also check for clearance between the bottom of the spring retainer and the valve seal at full lift.
Also check for coil bind in the springs. (spring stacking solid at or before full lift).