Well if your going to Turbo it than the Compression Ratio (C.R.) is maybe about right with the .030 overbore you are at 8.33 to 1 Static, a 58 CC Head combustion Chamber and the FelPro .050 Comp Head gasket would then put you at a 8.5 to 1 C.R.
All Small Six Timing issue
- Thread starter Angry b1rd
- Start date
This relates to all small sixes
Angry b1rd
New member
I was mistaken about the cam spacer. The one I have must be for a different application. It's a c5az-6265-a and does not fit the cam nose. It will push the cam too far bark when installed. Do you know the part number for the correct part?
No, I do not know the part number, I have just taken them off of old cams. Vintage Inlines has some. Where is your old cam.
Angry b1rd
New member
Machine shop scrapped it. Vintage inlines doesn't respond when I try to order from them. Thanks
Angry b1rd
New member
I followed your procedure today with the stock timing set. Came up with 66+160=226/2=113. I have the adjustable timing set and will install in the +4 degree slot and try to degree again. I will have to come up with a new cam spacer first as the one I stole from the 170 is broken
Here is were to get a new Cam Spacer Ring they also have new cam Retainer Plates too. https://www.vintageinlines.com/product-page/cam-spacer-small-six
I am rebuilding my 200. I have ordered flat top pistons with a custom compression height of 1.530 instead of milling a lot off of the block putting the top of the pistons even with the top of the block. With a felpro gasket compressed thickness of 0.041and my head combustion chambers cc'd to 59.00, this gives me a static compression of 9.22.
If you have the 62 chambered heads you can mill off about 0.003 to 59 cc's to make the flat area of the chamber even with the head surface increasing the quench area. You must do the math using accurate numbers.
If you want 9.2-9.5 compression ratio get rid of the dished pistons. If you are going to forced induction then leave the dished pistons although if you are going to use forced induction I would go to forged pistons. Make sure you gap the piston rings for forced induction if you plan on going this way.
If you have a NOS (0.022 I think) head gasket then your calculations will be different.
If you have the 62 chambered heads you can mill off about 0.003 to 59 cc's to make the flat area of the chamber even with the head surface increasing the quench area. You must do the math using accurate numbers.
If you want 9.2-9.5 compression ratio get rid of the dished pistons. If you are going to forced induction then leave the dished pistons although if you are going to use forced induction I would go to forged pistons. Make sure you gap the piston rings for forced induction if you plan on going this way.
If you have a NOS (0.022 I think) head gasket then your calculations will be different.
You did not follow my procedure. You are not even close.
Look at your cam card.
The intake lobe opens .050" at 7 degrees before TDC and closes .050" at 37 ABDC.
If you got those readings the .050" duration would be: 7+180 +37 = 224
Then the intake lobe center would be at 224/2 -7 = 105 degrees ATDC
If the intake lobe center is at 113 then the intake would open at 1 degree ATDC and close at 45 degrees ABDC.
The two points on the degree wheel would be 1 ATDC and 45 ABDC.
The cam would then be 8 degrees retarded.
How did you get 66 and 160???
It looks like you are still measuring down from the top of the cam lobe.
The cam card is asking you to measure .050" up from the bottom of the cam lobe.
The following instructions is the procedure used to do so.
This is what I wrote in post #9
Camshaft Timing:
The camshaft should be timed using the .050" duration method.
That is the reason for the opening and closing points shown on the cam card.
This time zero the dial when the lifter is all the way down on the heel of the cam.
Then turn the crankshaft CW until the dial reads .050" and record the wheel reading.
Continue turning the crank CW.
The dial will go past max lift and down.
When the dial reads .050" from the bottom, record the wheel reading.
It is IMPORTANT that the crank is alway being turned clockwise when taking degree wheel readings, so the timing chain slack doesn't introduce an error.
If you accidentally go past the .050" on your dial, back the crank up CCW and come back into the .050" reading CW.
If you look at the cam card, the first intake .050" reading as the lifter rises is at 7 degrees BTDC and is .050" from the bottom after max lift at 37 degrees ABDC.
Check the exhaust reading also just to see if the lobe separation angle is correct on the cam.
The exhaust opens 47 degrees BBDC and closes 3 degrees BTDC
Remember that the first lifter is the exhaust and the second one is the intake on number one cylinder.
There is an extremely important reason why we are asking you to check the cam timing using the .050" duration method.
There has been more than one occasion on this forum where the actual camshaft profile did not match the cam card which is what you are expecting the cam to be.
There was one case where a very large duration cam was accidentally shipped in the wrong cam box and the owner couldn't figure out why the engine was running so badly until we had him go back and check the actual cam profile with a degree wheel.
The only way to check the cam profile against the cam card specs is to look at the .050" opening and closing points shown on the cam card for both the intake and exhaust lobes.
There has been more than one occasion on this forum where the actual camshaft profile did not match the cam card which is what you are expecting the cam to be.
There was one case where a very large duration cam was accidentally shipped in the wrong cam box and the owner couldn't figure out why the engine was running so badly until we had him go back and check the actual cam profile with a degree wheel.
The only way to check the cam profile against the cam card specs is to look at the .050" opening and closing points shown on the cam card for both the intake and exhaust lobes.
Angry b1rd
New member
You're correct. I was measuring down from the lobe. I'm a little embarrassed to admit I didn't quite understand the instructions. After re reading the post I tried it from the heel as you said. And I'm reading 0-1 degree btdc and 44 abdc. Pretty close to where you said it would be. Exhaust looked like 39 bbdc and 5 atdc. Thanks for the education, keeping me honest, and not allowing me to cheat myself. I have placed an order to vintage inlines for cam spacers. If/when they get here I will install the adjustable timing set and try again. I'm trying to get it as close as I can beforehand because the cam sprocket on the double roller is a pretty tight fit and would prefer to not have to pull it off if it can be avoided.
Angry b1rd
New member
I have also noticed that the valve opening isn't as smooth as I would think it should be. On intake valve opening there is a .010 "blip" where there dial indicator shows initial lifter rise, goes back down to 0, and then begins the "actual" lift. Is this normal?
It looks like the cam needs to be advanced another 8 degrees
A .010" is a bit much.
Next time you pull out the cam have a look at the cam lobe and the cam core material next to the cam lobe.
May something is sticking up above the cam lobe heel and hitting the lifter.
It's normal to see between a .001" and .002" variation as the lobe travels across the heel of the cam lobe.
A .010" is a bit much.
Next time you pull out the cam have a look at the cam lobe and the cam core material next to the cam lobe.
May something is sticking up above the cam lobe heel and hitting the lifter.
I would wait till you get the cam spacer before spending time to degree now.
Angry b1rd
New member
If this is true, Is it not possible to advance the cam more to gain more low end? Is that something that's preferable on a cam ground straight up? Or even possible at at?
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The cam card is asking you to install the cam with the intake lobe center at 105 degrees ATDC.
That is 5 degrees advanced which is a lot considering most street cams are installed 4 degrees advanced at the most.
A 200 is a small displacement engine and will never have a lot of low end torque compared to a larger six like the 300.
The purpose of this cam is to make a lot of horsepower instead.
It may not pull hard till somewhere after 3000 rpm but once it comes on it will be a blast.
If you need to accelerate the vehicle hard from a low speed, downshift the transmission and get the engine back into the power band.
That is supposed to be the fun of having a 5 speed manual transmission.
My Dodge Caravan 3.6 V6 doesn't start to pull hard until 4000 rpm but once it gets there the 280 hp will set you back.
Meanwhile it is geared for 2000 rpm at 80 mph on the highway.
If I need to pass, the transmission downshifts and puts the engine back into the power band.
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Angry b1rd
New member
After much consideration I am considering a different cam. I do not want to raise compression to 10:1, nor do I care for a high reving motor. The cam I am now considering is the howard 280028-08.
The Howards 280028-08 has a tight 108 degree LSA that will affect idle quality and off idle torque.
However it does have a lot of low to midrange torque.
You would be looking at an 8.8 compression ratio.
I don't remember if you are going to use a long tube header?
However it does have a lot of low to midrange torque.
You would be looking at an 8.8 compression ratio.
I don't remember if you are going to use a long tube header?
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Angry b1rd
New member
I do have a split header I was planning to use on this motor. I am ok with a rough idle or lope.
