I have the William Burt book. Pretty easy reading. I'm always open for other suggestions. Thanks Guys.
First Engine Build
- Thread starter FJRdoc
- Start date
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I've been reading up on rocker arm geometry and I have some questions regarding my engine build. Hopefully, my engine block and components will be finished at the machine shop soon. I selected a Voodoo 703 hydraulic flat tappet cam, Comp Ultra Pro Magnum rockers, and Keith Black 243-.030 hyper pistons for my build. Cylinder heads have been worked over and valve stem heights checked. Calculated compression ratio will be 9.5:1.
I Know that I will need to measure for correct length pushrods for my application. I've been reading about using shims on the rocker shaft pedestals to achieve proper geometry. Do I need to concern myself with shims if I will be getting a custom length pushrod? I would also appreciate any recommendations regarding manufacturer selection.
I Know that I will need to measure for correct length pushrods for my application. I've been reading about using shims on the rocker shaft pedestals to achieve proper geometry. Do I need to concern myself with shims if I will be getting a custom length pushrod? I would also appreciate any recommendations regarding manufacturer selection.
nm9stheham
Well-Known Member
The rocker angle depends on both the pushrod length AND the installed valve stem height. If the valve stems are the right height to get the rocker angle right with valves closed, then the right length of the pushrods is all that is needed. The adjustment on the rockers makes it a littler easier to take up an variations. If the valves are not the right height to get the closed-valve rocker angles right, then the valves are either 'tipped' (ground down) if too long or replaced if too short. Hopefully, your shop got the valve heights right for the rocker angles when they set valve height, but I would double check each valve to be sure.
If vavles too long, then that is where some folks try a set of shims under the rocker shafts. Any shims need to be steel, not AL or brass, as the AL and brass will mushroom out with heat cycling and the rocker shaft will get loose. (A hard alloy like berylium copper or a hard AL might survive but why bother.....) I would prefer to tip long valves; shims have several possible issues.
BTW, I just read this thread, and I think you made a good decision on the flat tappet vs roller. You're cam is not that wild, and you are not after each little bit of lift and duration, so as to demand the rollers. Flat tappets have run great for decades.
And if I can add an IMO, break in the engine on regular non-synthetic oils and then switch to full synthetic after a few thousand miles. You will be happy. Mobil 1 at Walmart is not all that pricey.
If vavles too long, then that is where some folks try a set of shims under the rocker shafts. Any shims need to be steel, not AL or brass, as the AL and brass will mushroom out with heat cycling and the rocker shaft will get loose. (A hard alloy like berylium copper or a hard AL might survive but why bother.....) I would prefer to tip long valves; shims have several possible issues.
BTW, I just read this thread, and I think you made a good decision on the flat tappet vs roller. You're cam is not that wild, and you are not after each little bit of lift and duration, so as to demand the rollers. Flat tappets have run great for decades.
And if I can add an IMO, break in the engine on regular non-synthetic oils and then switch to full synthetic after a few thousand miles. You will be happy. Mobil 1 at Walmart is not all that pricey.
Thanks for the information nm9. This is my first endeavor into a complete engine rebuild and I'm trying to gather as much info on the topic as possible. I am a perfectionist by nature and I want to do this engine build correctly the first time.
moparlover
Well-Known Member
i would also recommend the the first book posted by rapid robert
that's the one i used and it was amazing.
that's the one i used and it was amazing.
I recently bought that book and I'm working my way through it.
Started assembling my engine over the weekend. Crank install went well without issues....so I thought. The Felpro rear main seal was installed, small amount of RTV applied to the adjoining areas and the cap was torqued down.
I was looking through the gasket set last night and found the installation tips. Instructions say to apply anaerobic sealant to mating surfaces of cap or block.Will I be able to remove the cap and reuse the main seal or should I play it safe and just purchase a new seal and start over?
I was looking through the gasket set last night and found the installation tips. Instructions say to apply anaerobic sealant to mating surfaces of cap or block.Will I be able to remove the cap and reuse the main seal or should I play it safe and just purchase a new seal and start over?
69_340_GTS
Well-Known Member
The RTV will work just fine. Personally, I wouldn't tear it back apart.
66dartgt
Well-Known Member
As long as you bedded the rear seal in RTV you will be fine.
dragondan64
Banned
Started to work on installing pistons in the block tonight and had problems. I have Keith Black 243 pistons. I read the included instructions and called for technical assistance. After discussing my build with the rep, I went with 0.028 end gap on the top ring and 0.18 end gap on the second. The oil rails had an end gap of 0.015 out of the box.
Rings were clocked in their proper positions and the piston was placed in the bore. I could not get the piston in the bore with a band type ring compressor. I did not beat on the piston to damage the rings. I was able to finally get the piston in with a tapered ring compressor, but the piston was tight and didn't move easily through the bore.
I removed the piston and removed the oil ring and rails and inserted the piston again.....it inserted easily and did not bind.
Sounds like I need to file the oil rail end gaps but I have not been able to find any recommendation online. Unfortunately, the Keith Black office is closed and of no help for the rest of the weekend.
I'm looking to my FABO brothers for some insight.
Rings were clocked in their proper positions and the piston was placed in the bore. I could not get the piston in the bore with a band type ring compressor. I did not beat on the piston to damage the rings. I was able to finally get the piston in with a tapered ring compressor, but the piston was tight and didn't move easily through the bore.
I removed the piston and removed the oil ring and rails and inserted the piston again.....it inserted easily and did not bind.
Sounds like I need to file the oil rail end gaps but I have not been able to find any recommendation online. Unfortunately, the Keith Black office is closed and of no help for the rest of the weekend.
I'm looking to my FABO brothers for some insight.
Finally got a call from the machinist that my engine was on the dyno and ready to fire up yesterday. I've been anxiously awaiting this moment.
One of the outer manifold studs had a coolant leak that needed to be repaired. My Pertronix ignition didn't work and required switching out the distributor. Oil pressure came up nicely with a priming rod.
The engine fired right up and ran nicely after timing was set. We noticed a slight miss during break-in and later check the spark plugs. I used Bosch platinums (probably not the best choice for break in) and a couple were fouled. Plugs were switched out for Autocrafts and she purred like a kitten.
Final numbers came out to 312 hp and 324 lbft of torque. I was hoping for bigger numbers but considering this was a fairly stock rebuild with factory car, intake and exhaust manifolds I think it's respectable.
I will need to pull the intake and reseal a small coolant leak in the front right corner. After that, she will be ready to paint and detail.
It sure was gratifying to hear her fire up without a problem. It's kinda like being in the delivery room when your children are born. It's exciting but scary until you realize that all is OK.
[ame="https://www.youtube.com/watch?v=54pHXam5co8"]1970 Duster 340 Final Dyno Run - YouTube[/ame]
One of the outer manifold studs had a coolant leak that needed to be repaired. My Pertronix ignition didn't work and required switching out the distributor. Oil pressure came up nicely with a priming rod.
The engine fired right up and ran nicely after timing was set. We noticed a slight miss during break-in and later check the spark plugs. I used Bosch platinums (probably not the best choice for break in) and a couple were fouled. Plugs were switched out for Autocrafts and she purred like a kitten.
Final numbers came out to 312 hp and 324 lbft of torque. I was hoping for bigger numbers but considering this was a fairly stock rebuild with factory car, intake and exhaust manifolds I think it's respectable.
I will need to pull the intake and reseal a small coolant leak in the front right corner. After that, she will be ready to paint and detail.
It sure was gratifying to hear her fire up without a problem. It's kinda like being in the delivery room when your children are born. It's exciting but scary until you realize that all is OK.
[ame="https://www.youtube.com/watch?v=54pHXam5co8"]1970 Duster 340 Final Dyno Run - YouTube[/ame]
Cool that you are a little closer.
About what I'd expect for power with stock exh manifolds and intake. A better intake and headers would raise hp number to the mid 330's, but, that's not what you are going for with the build.
Check that your intake gaskets are thick enough.
About what I'd expect for power with stock exh manifolds and intake. A better intake and headers would raise hp number to the mid 330's, but, that's not what you are going for with the build.
Check that your intake gaskets are thick enough.
I used the intake side gaskets that came in my Felpro set. Got rid of the end gaskets and used Permatex. Do you have any suggestions for better gaskets to use?
Measure the clearance. When you get the intake off, clean it up good. Put intake on and slide it to one side. Measure the gap, add .060 and divide by 2. That's how thick the gasket should be.
Thanks for the info crackedback
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