Pics of the bottom end together, some interesting pics of measurements
03-29-2008, 07:08 PM
#1
Safety Car
Thread Starter
Pics of the bottom end together, some interesting pics of measurements
I finally got the bottom end together today. It has been a bit if a nightmare due to the crank being a little over sized on the rod pins and my insistence on the bearing clearances I wanted to run. Today I finished stretching the rod bolts, degreed the cam, and took a few measurements I have always wondered about. The first two pics are of a rod bolt stretch gauge on a rod bolt. The first is with the rod bolt with no tension, and the second is the bolt stretched to .0065 (the gauge shows .007 due to the weight of the gauge when I let go of it to take the pic.) I used a tq wrench to help figure out the stretch and tq it took to get the proper .006-.0065 stretch on these ARP 3.5 bolts. I then wrote that number on the rod and crank journal for future reference. These bolts took between 100-130 ft. lbs to get .006-.0065 stretch
This pic is when I was verifying the lift on the intake lobe. You can see the gauge reads 00. The lifter is on the base circle portion of the intake lobe.
This is a pic of the lifter on the highest point of the cam. The gauge went around 4 times and then rested on 72. The total lift at the cam is .472. I am running 1.8 rockers so the lift at the valve is a theoretical 849.6 if you subtract the lash (.025) you get the actual valve lift of .8246.
Ever wondered where your piston is in the bore when the spark plug fires at 36* BTDC. Now you know, here is a pic. BTW it is .5625 in. down in the bore
If you are running a bit of spray you might run 26* of timing (bout a 250-300 shot) The piston is now .2960 in. in the hole. The piston moves up the bore .2665 in. in that 10 degrees.
The cam shaft I am using opens the intake valve at 30* BTDC (before top dead center) and closes at 78 ABDC (after bottom dead center). I did not get a pic of the piston at 30 BTDC but you can get a good idea if you look at the pic of it at 36*. Here is a pic of the piston all the way down in the hole (4.25) it then moves up the bore and the intake valve closes as the piston is moving up the bore
Here is a pic of the piston at 78* ABDC (when the intake closes) The piston at this point is 2.9535 from the deck, so it has moved up the bore 1.2969 in. before the intake valve closes !! All of these measurements where actually at .050 lifter lift, but close enough for an illustration.
One last pic of the bottom end all bolted up !!
This pic is when I was verifying the lift on the intake lobe. You can see the gauge reads 00. The lifter is on the base circle portion of the intake lobe.
This is a pic of the lifter on the highest point of the cam. The gauge went around 4 times and then rested on 72. The total lift at the cam is .472. I am running 1.8 rockers so the lift at the valve is a theoretical 849.6 if you subtract the lash (.025) you get the actual valve lift of .8246.
Ever wondered where your piston is in the bore when the spark plug fires at 36* BTDC. Now you know, here is a pic. BTW it is .5625 in. down in the bore
If you are running a bit of spray you might run 26* of timing (bout a 250-300 shot) The piston is now .2960 in. in the hole. The piston moves up the bore .2665 in. in that 10 degrees.
The cam shaft I am using opens the intake valve at 30* BTDC (before top dead center) and closes at 78 ABDC (after bottom dead center). I did not get a pic of the piston at 30 BTDC but you can get a good idea if you look at the pic of it at 36*. Here is a pic of the piston all the way down in the hole (4.25) it then moves up the bore and the intake valve closes as the piston is moving up the bore
Here is a pic of the piston at 78* ABDC (when the intake closes) The piston at this point is 2.9535 from the deck, so it has moved up the bore 1.2969 in. before the intake valve closes !! All of these measurements where actually at .050 lifter lift, but close enough for an illustration.
One last pic of the bottom end all bolted up !!
Last edited by 69 N.O.X. RATT; 03-29-2008 at 07:12 PM.
03-29-2008, 07:19 PM
#2
Safety Car
Thread Starter
BTW, the engine is a 555. 4.25x4.560
Cam is .850 intake (per the card) .831 exhaust on a 114 LSA installed 1/2 degree advanced at 113.5 ICL
288 and 308 at .050
Cam is .850 intake (per the card) .831 exhaust on a 114 LSA installed 1/2 degree advanced at 113.5 ICL
288 and 308 at .050
Last edited by 69 N.O.X. RATT; 03-30-2008 at 12:25 AM.
03-29-2008, 08:00 PM
#4
Team Owner
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Well Thank You! I'm positive now that I don't know anything that matters about building a REAL motor.
Regards,
Alan
Regards,
Alan
03-29-2008, 09:22 PM
#5
Burning Brakes
I know more than the average person about how an engine works but darn, I don't know beans about the measurements, LSA etc. Great pictures.
Last edited by BB68Vett; 03-29-2008 at 10:19 PM.
03-29-2008, 09:43 PM
#6
Race Director
Great pics and comments. What block is that ? My new Motown block has that main cap setup. All five caps billet steel 4 bolt with the center 3 splayed, should be strong enough for going to the corner store 
03-29-2008, 10:17 PM
#9
Team Owner
I'm surprised that you have steel rods. BME sells these for a set of 10 for under $5000
Out of my friends blower motor.. 52 psi on alki
Out of my friends blower motor.. 52 psi on alki
03-29-2008, 11:03 PM
#10
Safety Car
Thread Starter
George, I really debated back and forth on whether to run steel or aluminum. I kept coming back to the fact that the car is only certified to run 7.50 and I do not think it will take much more than 300 hp worth of nitrous to do it. I will spray the heck out of it every now and then to see what I can get away with 7.20's ? 7 teens ? who knows. If I were going to spray 500+ all the time and rpm it to the moon I would run GRP aluminum rods in it.
The real advantage to an aluminum rod is they act like a shock absorber for the bearing and crank; if I stay on top of the tune and keep it out of detonation, it should never be a problem. I know of guys spraying 700+ with steel rods in 632's.
The block is a GM CNC Pro-Stock Bowtie.
The real advantage to an aluminum rod is they act like a shock absorber for the bearing and crank; if I stay on top of the tune and keep it out of detonation, it should never be a problem. I know of guys spraying 700+ with steel rods in 632's.
The block is a GM CNC Pro-Stock Bowtie.
Last edited by 69 N.O.X. RATT; 03-29-2008 at 11:06 PM.
03-30-2008, 12:06 AM
#11
Race Director
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2020 C2 of the Year - Modified Winner
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Sweeetttt!!!
Lookin' good John. great pics to show what is really going on in there!
Lookin' forward to new timeslips!! And dyno numbers!
JIM
Lookin' good John. great pics to show what is really going on in there!
Lookin' forward to new timeslips!! And dyno numbers!
JIM
03-30-2008, 12:10 AM
#12
Team Owner
I was just kidding! My friend has too much money so his blown alki goes though pistons when it leans out.
I bought that magnetic arm dial indicator to do my valves also. So quick and presice compared to a feeler gauge.
My first practice race weekend is April 5-6. Reno road racing 4.2 mile track
Way to much to sort out............... for the first points race on april 26th SCCA
They don't allow N2O 175 SHOTS during a race. But it would be fun for hidden passing power
I bought that magnetic arm dial indicator to do my valves also. So quick and presice compared to a feeler gauge.
My first practice race weekend is April 5-6. Reno road racing 4.2 mile track
Way to much to sort out............... for the first points race on april 26th SCCA
They don't allow N2O 175 SHOTS during a race. But it would be fun for hidden passing power
03-30-2008, 12:28 AM
#13
Wow must be really first class rod bolts to handle 100/130 lb ft. like to fell over
when I read that, what kind of rods and rod bolts are they.
when I read that, what kind of rods and rod bolts are they.
Last edited by Little Mouse; 03-30-2008 at 12:34 AM.
03-30-2008, 12:42 AM
#14
Burning Brakes
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03-30-2008, 12:51 AM
#15
Safety Car
Thread Starter
They are the toughest rod bolt ARP makes, called the 3.5. 41 bucks each !! ouch.......
Only 2 bolts got .006 with 100 lbs. Most only went .005 with 100 ft. lbs. Two different tq wrenches. My buddy is an old time engine builder and he did not believe it either till he pulled one himself.....then he just wandered off muttering to himself. LOL !! If you pick one up they just feel stout, very heavy for their size.
I saw a set on a boat motor one time that spun a rod bearing and got the crank so hot it melted a hole in it; rod bolts did not break. They are nearly impervious to heat. The metal they are made from is used for fasteners in jet engines.
Only 2 bolts got .006 with 100 lbs. Most only went .005 with 100 ft. lbs. Two different tq wrenches. My buddy is an old time engine builder and he did not believe it either till he pulled one himself.....then he just wandered off muttering to himself. LOL !! If you pick one up they just feel stout, very heavy for their size.
I saw a set on a boat motor one time that spun a rod bearing and got the crank so hot it melted a hole in it; rod bolts did not break. They are nearly impervious to heat. The metal they are made from is used for fasteners in jet engines.
Last edited by 69 N.O.X. RATT; 03-30-2008 at 12:55 AM.
03-30-2008, 01:18 AM
#16
Race Director
Aluminum rods are only good for around 40 runs. At least in my applications. The block looks to be cast iron when pictureed with the lifters and then at the bores it shows what could possibly be sleeves instead of 'O' rings. Is the block aluminum or what?
03-30-2008, 01:19 AM
#17
Burning Brakes
Nice work! 
How high do you plan to spin it? Any ETA on first fire-up?
Mark
How high do you plan to spin it? Any ETA on first fire-up?
Mark
03-30-2008, 01:50 AM
#18
Safety Car
Thread Starter
The block is cast iron. The O-rings are in the heads and the block is cut for the receiver grooves.
Mark, I ain't skeered of 8500 rpms, but will probably shift at 8000 NA and 7500-7800 on nitrous.
No idea when I am going to fire it up, still have to find a dyno that will let me make pulls on it; and that I am comfortable with. I called Joe Sherman the other day and he told me I would break his dyno.
Mark, I ain't skeered of 8500 rpms, but will probably shift at 8000 NA and 7500-7800 on nitrous.
No idea when I am going to fire it up, still have to find a dyno that will let me make pulls on it; and that I am comfortable with. I called Joe Sherman the other day and he told me I would break his dyno.
03-30-2008, 09:44 AM
#20
Instructor
Great pics. I debated the steel vs aluminum rod deal when I built the 598ci that is in my '81 drag car. I went with GPR 6.7" aluminum rods due to their great reputation and strong design. My cam is very close to yours with .867" I, .780" E, with 288/304 @ .050" on a 114 LSA. I put it in at 111 but wish I had installed it at 113 or 114 straight up.
Interesting about the rod bolt stretch. The GRPs came with ARP 2000 bolts and the recommended torque was 75# OR .0055" - .006" stretch. It took roughly 90# to stretch those properly. I've run this motor for 2 years now and about 150 passes or so. Good luck with your project.
www.putfile.com/nobody2
Interesting about the rod bolt stretch. The GRPs came with ARP 2000 bolts and the recommended torque was 75# OR .0055" - .006" stretch. It took roughly 90# to stretch those properly. I've run this motor for 2 years now and about 150 passes or so. Good luck with your project.
www.putfile.com/nobody2