hi everybody so recently i got gifted a ton of 351 and 302 parts and i have a question because while i have changed whole motors and and intakes i still have yet to do a head install. I was given a pair pf x302 ford raving heads for 302/351 and i was wondering could i reuse the springs, roller rockers n such from my stock e7 heads ? Im gunna put a b or e cam maybe a trick flow stage 1 ??in the carbecause it seems pretty retarded not to do the cam when im already right there but its a daily driver street car so nothing crazy
Engine 5.0 aluminum head install
- Thread starter jakeklein89
- Start date
-
- Tags
- foxbody 5.0 hci swap gt40
-
Sponsors (?)
Steel1
Mustang Master
Yes you'll need better springs.
If the new heads are pedestal mount you could reuse your rockers,
if stud mount you'll be buying new rockers as well.
If the new heads are pedestal mount you could reuse your rockers,
if stud mount you'll be buying new rockers as well.
Yeah you guys are right i was just trying to see if i could reuse some parts to save some cash cause the budget is tight rn.... just super excited to get these heads on ! Never would i have ever thought i could get a set of aluminum heads for free never put on and they have already had some bowl work done !
Are you doing the port work? There is alot more to it then just removing material, a poorly done port job can actually reduce flow from velocity loss. IMHO I would not touch them unless you have experience doing so. The gt40x are nice heads for a streetcar, I suggest any cam that is not a frpp letter cam.
Oh absolutely i am very aware of how badly porting can go without experience i have several sets of iron heads im going too practice on before doing my aluminum heads and if i dont feel confident im going to pay to have them done right but they will definitely be ported and polished before going on the car because there are some slight casting flaws and i dont want any detonation problems or anything so im just gunna make sure and take care of everything first
@jakeklein89
Cylinder head swap by Michael Yount
Join Date: April 2002
Location: Knoxville,TN
Posts: 8,459
Here's some miscellaneous tips I wrote up for some other thread -- not organized, but most say helpful. I know they've helped me....
Many balancers will go back on quite easily by hand, and then pulling it on with the bolt. Just be absolutely certain you can engage the keyway by hand before tightening with the bolt. If the balancer fit is too tight for that then use the install tool. It's impossible to predict how any particular balancer is gonna fit on a particular engine - you may need the install tool; you may not.
There's a very specific procedure for INSTALLING pedestal mount rocker arms on these cars. They are not adjustable per se. Go to www.cranecams.com and download the instructions for installing their 1.7 ratio Cobra style roller rockers - that's the proper way to install them. You may have to re-install them once you've cranked it and warmed everything up - that may help quiet them if they're noisy on the first crank up.
Be sure to prime the oil system through the distributor hole. Autozone will loan you a tool for that as well. You'll probably also need fuel line disconnect tools - AutoZone will sell you those for a few bucks.
If the hoses/belts/t'stat haven't been replaced within the last year or so, it's easiest and preferred to simply buy new hoses/clamps/t'stat/belt and put them in. Also makes disassembly much easier -- just cut the hoses off. This includes vacuum hoses. And be sure the o-rings on the injectors are new and lubed on both ends.
Don't trust your memory - unless you've worked on these engines a lot, use masking tape and a permanent marker to mark every connection (elec, vacuum, coolant, fuel) as you disassemble. It will make reassembly MUCH easier.
Keep everything as clean as you can. Plan on an oil/filter change -- some coolant almost always gets into the pan. Change the oil (use an inexpensive oil) before you prime/crank the car, but leave the old filter in -- it will catch any post assembly debris. AFter the first few heat cycles, change the oil again with the good stuff, and then put a new filter on it.
There is a specific counter-intuitive pattern for tightening the lower intake bolts. Use it (manual). Ignore any counsel from head or manifold companies to the contrary --- ABSOLUTELY use a torque wrench on the lower and upper intake. Take them to torque in at least 3 increments; no more than 18-20 ft-lbs. on the lower; NO MORE than 10 ft-lbs. on the upper.
Go to a hardware store with one of the valve cover, header, lower intake, and upper intake (short ) bolts. Buy bolts of similar length and the same dia/pitch threads as follows - 2 header, 2 valve cover, 2 upper intake (short bolts) and 4 lower intake. Cut the heads off of these and screw them in as studs/temporary dowels. They'll hold gaskets in place and allow you to place the components perfectly without moving the gaskets out of alignment - particularly helpful if you're working alone on headers, upper and lower intake. Once you've 'stuck' the part, put a few of the 'real' bolts in to hold it, then remove the studs, and put the rest of the bolts in. That tip is a real time saver and insures a quality job with gaskets.
Be sure to cover openings so stuff doesn't fall where you can't reach it. Intake/exhaust ports; the front of the oil pan when the front cover is removed; the distributor hole -- all of these are 'magnets' for stuff you don't want in them.
The shop vac is your friend to clean up any gasket scrapings.
Be sure to degree the cam (indexed timing chain, degree wheel, dial indicator required). DO NOT use a dot to dot install - degreeing will not only teach you volumes about how your engine works, it will guarantee correct cam timing removing that as a variable if the engine's not running right when you crank it. Furthermore - you'll need the dial indicator and degree wheel to check p to v clearance. NO ONE CAN TELL YOU IF YOU HAVE ENOUGH CLEARANCE on your engine. You must measure - especially with new heads/cam. Don't guess - measure - know.
If you rotate the engine to where the ignition timing pointer is pointing to tdc and the rotor is pointing to the #1 cylinder (pop the dist. cap) - use a Sharpie marker to mark 1) the dist. housing - align it with a mark on the block, and 2) the point on the housing where the rotor is pointing. When you get ready to put it back together, simply rotate the engine to tdc at the beginning of the power stroke - and insert the distributor so the housing/block marks match, and the rotor is pointing at the mark on the housing. You'll be back to where ever you had the timing before - and the car should start. Then time it with a light. It'll want more advance with the cam - try starting around 14-16 btdc.
Front cover is a chore for most - I had a hard time with mine. You may have to cut the oil pan gasket and replace just the pieces under cover. Use a dab of rtv at any place where you have 3 surfaces coming together in different planes - front cover/pan/block and lower intake/head/block. On paper gaskets use Permatex Hylomar gasket dressing (not rtv); on rubber gaskets (and injector o-rings) just use a little light grease to keep them from binding. On head gaskets and any graphite impregnated gaskets (sometimes lower/upper intake and exhaust) install them dry. On your headers, check the flange for straightness/true with a straight edge. If they're warped, getting them to reseal can be near impossible. While you're working on it, have a machine shop mill the flange to re-true it. It'll seal like a champ.
Most of all, take your time and have fun. Good luck.
To install pedestal mount rockers:
1) For each pair (int/exh) be sure you rotate the engine so the lifters are on the base circle of the cam - this is very important. When you install the rockers, both valves must remain closed. Neither lifter can be on any part of the cam lobe - they MUST be on the base circle. Rotate the engine clockwise. Watch the pushrods for the pair you're installing. The exh will rise and fall; as it's about to 'close' (fall back down) the intake will rise. Keep rotating until the intake falls back down (closed) and both the intake and exhaust pushrods are the same height. You're now on the base circle of the cam at the beginning of the compression stroke for that cylinder.
2) Install the rocker and bolt it down to zero lash. Zero lash is reached just when you eliminate the gap between the pushrod and the rocker and the valve stem and the rocker. Tighten with one hand and 'rock' the rocker with the other hand. Just when you reach the point that you can't rock the rocker anymore you're at zero lash.
3) Now - put your torque wrench on it and tighten to 18-20 ft-lbs. while counting the number of turns it takes to reach that torque. It should occur between 1/4 turns and 1 turn. If it takes more than one turn, use a shim to raise the rocker. For each .030" shim you use, you'll reduce the number of turns to torque by about 1/4. If it takes less than 1/4 turn, or you have trouble reaching zero lash even with the bolt torqued all the way to 18-20, then you need longer pushrods.
4) If all goes well on the install, crank it up. If some make noise let the car warm up completely. Then (unfortunately) go back through the install procedure with the components warm. That will usually quiet them down.
Mine has 11 with no shims at all, 4 with one .030" shim, and one with 2 .030" shims. And I had to do the final install with it hot to get them quiet. That approach has them all hitting the required torque within 1/2 to 3/4 turns.
I have a Buddy Rawls custom cam with fairly steep ramp rates, 1.7 roller rockers (pedestal Cobra type), and stock lifters. It runs just about as quiet as it did stock.
Determining TDC, cam degree and p to v clearance
Positive stop – obtain an old spark plug for the Ford engine – most of us have at least one laying around. Put it in your vice, and with a tool of destruction you deem appropriate – cut off the ground tip and bust up the ceramic around the center electrode. Keep pounding to get the ceramic and center electrode removed so you’ve got a good ¾” or so of hollow space inside what used to be the ‘business’ end of the spark plug. If you happen to break the ceramic on the other end of the spark plug, don’t worry about it. Once you’ve got a nice hollow space in the tip of the plug, take a 5/16” tap, and cut threads inside that end of the plug. I found that diameter to go right in without any drilling required. Once you’ve cut threads, screw in a 5/16" bolt about 1.5” to 2” long. Then take your hack saw and cut the head off the bolt. Wouldn’t hurt to take your file/grinder and dress up the freshly cut surface so no sharp edges or shrapnel enter the combustion chamber. Also clean up the threads on the plug so that it easily screws into and out of the plug hole.
Determining TDC – remove the passenger side valve cover. Remove rockers from the intake and exhaust valves on the #1 cylinder. Rotate the engine (socket on crank bolt) until the #1 piston is down the cylinder on the intake stroke. Unscrew the spark plug in that cylinder, and replace it with the positive stop you just made. Only screw the positive stop in hand tight. Install your cam degree wheel and pointer (no easy task in some cases as harmonic balancer and other accessories will have to be removed). You may want to remove all spark plugs at this point because it will make it easier to smoothly turn the engine over in small increments. GENTLY rotate the engine clockwise until the piston comes to rest against the stop. Note the degree wheel reading. GENTLY rotate the engine in the opposite direction until the piston comes to rest against the stop. Note the degree wheel reading. TDC is exactly half way between these readings. Calculate where that position is on the degree wheel, remove the piston stop from the cylinder, and rotate the engine to TDC as you calculated it.
Degreeing the cam – install the camshaft in the straight up or dot to dot position to start with. Set your dial indicator up over the #1 intake valve lifter or pushrod. Rotate the engine clockwise until the intake lifter/pushrod just begins to rise. Follow the dial indicator and stop the rotation when the lifter is at .050” lift. Take a reading on the degree wheel. It should match your cam card information for the number of degrees at .050” lift on intake valve opening. For example, the cam card on an E303 cam says that the intake should be open .050” right at top dead zero – 0 degrees TDC. So if you rotate the engine until your dial indicator shows .050” lift on the intake opening, the your degree wheel should be pointing right at tdc. If you’re within a degree or two, then you can go ahead and check the .050” closing timing, as well as the opening and closing events for the exhaust valve. They should all match up with the cam card info within a degree or two. If, for example, at .050” you’re supposed to be at 0 degrees TDC (from the cam card), and after your dot to dot install you’re reading 4 degrees after TDC at .050”, then the intake valve is opening too late (4 degrees later than it should). To adjust this, you need to make the intake open 4 degrees earlier (right at tdc), so you’ll have to advance the cam by 4 degrees. To do this you slide your indexed timing set off, you select the “4A” slot on the crank gear (instead of the straight up position), align it with the dot on the cam gear and reinstall. Remeasure as described above – you should now read .050” lift right at TDC. Many contemporary cams have assymetrical lobes – so I wouldn’t install the cam using the lobe centerline method – the centerline can be difficult to find. I recommend using the .050” lift timing events for the install – check all 4 of them to be sure the cam is doing what the cam card says it should be doing.
Drop valve measurement – now that the piston is at TDC (be sure you're at TDC during overlap - between exhaust and intake strokes) you can safely remove the valve springs on the intake and exhaust valves. I used an inexpensive KD tool for a small block Chevrolet (Blasphemy!). It bolts into the pedestal and has a crow’s foot that sits over the spring retainer. It’s nothing more than a pry bar. Be sure to screw the rocker bolt far enough into the pedestal to hold the tool. You (or your big friend Bubba) are going to apply significant force on the lever to compress the spring. A small magnet is invaluable for grabbing the keepers once the spring is compressed. Also, a couple of taps (lightly – careful here) with a hammer on the retainer can help free up the keepers. The valves may or may not drop down and touch the piston – be sure it’s at TDC to limit the valve movement. Set up your dial indicator over each valve. Rotate the engine to about 20 degrees BTDC. Now, in 5 degree increments, until you reach 20 degrees ATDC measure the distance between valve closed and valve touching the piston. You can move the valve up and down with your fingers, or if the seals are loose, up with your fingers, gravity will take care of down. You’ll have maps of closed valve to piston contact distances every 5 degrees from 20 BTDC to 20 ATDC for intake and exhaust. Rotate the engine back to 20 BTDC (back the way you just came – if you rotate the other way, the piston will drop all the way to the bottom and you’ve got valves dropping down into the cylinders – DON’T DO THAT!!) and set the dial indicator up over the intake and exhaust lifters (or pushrods if you don't have a dial indicator extension). Make the same measurements on both lobes – a map of lift on intake and exhaust lift at 5 degree increments from 20 BTDC to 20 ATDC. Multiply the lift times the rocker ratio. That is valve lift. At each 5 degree point, subtract valve lift from the valve closed to piston contact measurement. That is your piston to valve clearance. It should be more than .080” on intake and .100” on exhaust for engines revving less than 6500 rpm. As your rpm increases, your clearance should increase. If you’re revving to 8500 rpm, you probably want on the order of .125” to 150” on intake/exhaust to be safe.
__________________
Cylinder head swap by Michael Yount
Join Date: April 2002
Location: Knoxville,TN
Posts: 8,459
Here's some miscellaneous tips I wrote up for some other thread -- not organized, but most say helpful. I know they've helped me....
Many balancers will go back on quite easily by hand, and then pulling it on with the bolt. Just be absolutely certain you can engage the keyway by hand before tightening with the bolt. If the balancer fit is too tight for that then use the install tool. It's impossible to predict how any particular balancer is gonna fit on a particular engine - you may need the install tool; you may not.
There's a very specific procedure for INSTALLING pedestal mount rocker arms on these cars. They are not adjustable per se. Go to www.cranecams.com and download the instructions for installing their 1.7 ratio Cobra style roller rockers - that's the proper way to install them. You may have to re-install them once you've cranked it and warmed everything up - that may help quiet them if they're noisy on the first crank up.
Be sure to prime the oil system through the distributor hole. Autozone will loan you a tool for that as well. You'll probably also need fuel line disconnect tools - AutoZone will sell you those for a few bucks.
If the hoses/belts/t'stat haven't been replaced within the last year or so, it's easiest and preferred to simply buy new hoses/clamps/t'stat/belt and put them in. Also makes disassembly much easier -- just cut the hoses off. This includes vacuum hoses. And be sure the o-rings on the injectors are new and lubed on both ends.
Don't trust your memory - unless you've worked on these engines a lot, use masking tape and a permanent marker to mark every connection (elec, vacuum, coolant, fuel) as you disassemble. It will make reassembly MUCH easier.
Keep everything as clean as you can. Plan on an oil/filter change -- some coolant almost always gets into the pan. Change the oil (use an inexpensive oil) before you prime/crank the car, but leave the old filter in -- it will catch any post assembly debris. AFter the first few heat cycles, change the oil again with the good stuff, and then put a new filter on it.
There is a specific counter-intuitive pattern for tightening the lower intake bolts. Use it (manual). Ignore any counsel from head or manifold companies to the contrary --- ABSOLUTELY use a torque wrench on the lower and upper intake. Take them to torque in at least 3 increments; no more than 18-20 ft-lbs. on the lower; NO MORE than 10 ft-lbs. on the upper.
Go to a hardware store with one of the valve cover, header, lower intake, and upper intake (short ) bolts. Buy bolts of similar length and the same dia/pitch threads as follows - 2 header, 2 valve cover, 2 upper intake (short bolts) and 4 lower intake. Cut the heads off of these and screw them in as studs/temporary dowels. They'll hold gaskets in place and allow you to place the components perfectly without moving the gaskets out of alignment - particularly helpful if you're working alone on headers, upper and lower intake. Once you've 'stuck' the part, put a few of the 'real' bolts in to hold it, then remove the studs, and put the rest of the bolts in. That tip is a real time saver and insures a quality job with gaskets.
Be sure to cover openings so stuff doesn't fall where you can't reach it. Intake/exhaust ports; the front of the oil pan when the front cover is removed; the distributor hole -- all of these are 'magnets' for stuff you don't want in them.
The shop vac is your friend to clean up any gasket scrapings.
Be sure to degree the cam (indexed timing chain, degree wheel, dial indicator required). DO NOT use a dot to dot install - degreeing will not only teach you volumes about how your engine works, it will guarantee correct cam timing removing that as a variable if the engine's not running right when you crank it. Furthermore - you'll need the dial indicator and degree wheel to check p to v clearance. NO ONE CAN TELL YOU IF YOU HAVE ENOUGH CLEARANCE on your engine. You must measure - especially with new heads/cam. Don't guess - measure - know.
If you rotate the engine to where the ignition timing pointer is pointing to tdc and the rotor is pointing to the #1 cylinder (pop the dist. cap) - use a Sharpie marker to mark 1) the dist. housing - align it with a mark on the block, and 2) the point on the housing where the rotor is pointing. When you get ready to put it back together, simply rotate the engine to tdc at the beginning of the power stroke - and insert the distributor so the housing/block marks match, and the rotor is pointing at the mark on the housing. You'll be back to where ever you had the timing before - and the car should start. Then time it with a light. It'll want more advance with the cam - try starting around 14-16 btdc.
Front cover is a chore for most - I had a hard time with mine. You may have to cut the oil pan gasket and replace just the pieces under cover. Use a dab of rtv at any place where you have 3 surfaces coming together in different planes - front cover/pan/block and lower intake/head/block. On paper gaskets use Permatex Hylomar gasket dressing (not rtv); on rubber gaskets (and injector o-rings) just use a little light grease to keep them from binding. On head gaskets and any graphite impregnated gaskets (sometimes lower/upper intake and exhaust) install them dry. On your headers, check the flange for straightness/true with a straight edge. If they're warped, getting them to reseal can be near impossible. While you're working on it, have a machine shop mill the flange to re-true it. It'll seal like a champ.
Most of all, take your time and have fun. Good luck.
To install pedestal mount rockers:
1) For each pair (int/exh) be sure you rotate the engine so the lifters are on the base circle of the cam - this is very important. When you install the rockers, both valves must remain closed. Neither lifter can be on any part of the cam lobe - they MUST be on the base circle. Rotate the engine clockwise. Watch the pushrods for the pair you're installing. The exh will rise and fall; as it's about to 'close' (fall back down) the intake will rise. Keep rotating until the intake falls back down (closed) and both the intake and exhaust pushrods are the same height. You're now on the base circle of the cam at the beginning of the compression stroke for that cylinder.
2) Install the rocker and bolt it down to zero lash. Zero lash is reached just when you eliminate the gap between the pushrod and the rocker and the valve stem and the rocker. Tighten with one hand and 'rock' the rocker with the other hand. Just when you reach the point that you can't rock the rocker anymore you're at zero lash.
3) Now - put your torque wrench on it and tighten to 18-20 ft-lbs. while counting the number of turns it takes to reach that torque. It should occur between 1/4 turns and 1 turn. If it takes more than one turn, use a shim to raise the rocker. For each .030" shim you use, you'll reduce the number of turns to torque by about 1/4. If it takes less than 1/4 turn, or you have trouble reaching zero lash even with the bolt torqued all the way to 18-20, then you need longer pushrods.
4) If all goes well on the install, crank it up. If some make noise let the car warm up completely. Then (unfortunately) go back through the install procedure with the components warm. That will usually quiet them down.
Mine has 11 with no shims at all, 4 with one .030" shim, and one with 2 .030" shims. And I had to do the final install with it hot to get them quiet. That approach has them all hitting the required torque within 1/2 to 3/4 turns.
I have a Buddy Rawls custom cam with fairly steep ramp rates, 1.7 roller rockers (pedestal Cobra type), and stock lifters. It runs just about as quiet as it did stock.
Determining TDC, cam degree and p to v clearance
Positive stop – obtain an old spark plug for the Ford engine – most of us have at least one laying around. Put it in your vice, and with a tool of destruction you deem appropriate – cut off the ground tip and bust up the ceramic around the center electrode. Keep pounding to get the ceramic and center electrode removed so you’ve got a good ¾” or so of hollow space inside what used to be the ‘business’ end of the spark plug. If you happen to break the ceramic on the other end of the spark plug, don’t worry about it. Once you’ve got a nice hollow space in the tip of the plug, take a 5/16” tap, and cut threads inside that end of the plug. I found that diameter to go right in without any drilling required. Once you’ve cut threads, screw in a 5/16" bolt about 1.5” to 2” long. Then take your hack saw and cut the head off the bolt. Wouldn’t hurt to take your file/grinder and dress up the freshly cut surface so no sharp edges or shrapnel enter the combustion chamber. Also clean up the threads on the plug so that it easily screws into and out of the plug hole.
Determining TDC – remove the passenger side valve cover. Remove rockers from the intake and exhaust valves on the #1 cylinder. Rotate the engine (socket on crank bolt) until the #1 piston is down the cylinder on the intake stroke. Unscrew the spark plug in that cylinder, and replace it with the positive stop you just made. Only screw the positive stop in hand tight. Install your cam degree wheel and pointer (no easy task in some cases as harmonic balancer and other accessories will have to be removed). You may want to remove all spark plugs at this point because it will make it easier to smoothly turn the engine over in small increments. GENTLY rotate the engine clockwise until the piston comes to rest against the stop. Note the degree wheel reading. GENTLY rotate the engine in the opposite direction until the piston comes to rest against the stop. Note the degree wheel reading. TDC is exactly half way between these readings. Calculate where that position is on the degree wheel, remove the piston stop from the cylinder, and rotate the engine to TDC as you calculated it.
Degreeing the cam – install the camshaft in the straight up or dot to dot position to start with. Set your dial indicator up over the #1 intake valve lifter or pushrod. Rotate the engine clockwise until the intake lifter/pushrod just begins to rise. Follow the dial indicator and stop the rotation when the lifter is at .050” lift. Take a reading on the degree wheel. It should match your cam card information for the number of degrees at .050” lift on intake valve opening. For example, the cam card on an E303 cam says that the intake should be open .050” right at top dead zero – 0 degrees TDC. So if you rotate the engine until your dial indicator shows .050” lift on the intake opening, the your degree wheel should be pointing right at tdc. If you’re within a degree or two, then you can go ahead and check the .050” closing timing, as well as the opening and closing events for the exhaust valve. They should all match up with the cam card info within a degree or two. If, for example, at .050” you’re supposed to be at 0 degrees TDC (from the cam card), and after your dot to dot install you’re reading 4 degrees after TDC at .050”, then the intake valve is opening too late (4 degrees later than it should). To adjust this, you need to make the intake open 4 degrees earlier (right at tdc), so you’ll have to advance the cam by 4 degrees. To do this you slide your indexed timing set off, you select the “4A” slot on the crank gear (instead of the straight up position), align it with the dot on the cam gear and reinstall. Remeasure as described above – you should now read .050” lift right at TDC. Many contemporary cams have assymetrical lobes – so I wouldn’t install the cam using the lobe centerline method – the centerline can be difficult to find. I recommend using the .050” lift timing events for the install – check all 4 of them to be sure the cam is doing what the cam card says it should be doing.
Drop valve measurement – now that the piston is at TDC (be sure you're at TDC during overlap - between exhaust and intake strokes) you can safely remove the valve springs on the intake and exhaust valves. I used an inexpensive KD tool for a small block Chevrolet (Blasphemy!). It bolts into the pedestal and has a crow’s foot that sits over the spring retainer. It’s nothing more than a pry bar. Be sure to screw the rocker bolt far enough into the pedestal to hold the tool. You (or your big friend Bubba) are going to apply significant force on the lever to compress the spring. A small magnet is invaluable for grabbing the keepers once the spring is compressed. Also, a couple of taps (lightly – careful here) with a hammer on the retainer can help free up the keepers. The valves may or may not drop down and touch the piston – be sure it’s at TDC to limit the valve movement. Set up your dial indicator over each valve. Rotate the engine to about 20 degrees BTDC. Now, in 5 degree increments, until you reach 20 degrees ATDC measure the distance between valve closed and valve touching the piston. You can move the valve up and down with your fingers, or if the seals are loose, up with your fingers, gravity will take care of down. You’ll have maps of closed valve to piston contact distances every 5 degrees from 20 BTDC to 20 ATDC for intake and exhaust. Rotate the engine back to 20 BTDC (back the way you just came – if you rotate the other way, the piston will drop all the way to the bottom and you’ve got valves dropping down into the cylinders – DON’T DO THAT!!) and set the dial indicator up over the intake and exhaust lifters (or pushrods if you don't have a dial indicator extension). Make the same measurements on both lobes – a map of lift on intake and exhaust lift at 5 degree increments from 20 BTDC to 20 ATDC. Multiply the lift times the rocker ratio. That is valve lift. At each 5 degree point, subtract valve lift from the valve closed to piston contact measurement. That is your piston to valve clearance. It should be more than .080” on intake and .100” on exhaust for engines revving less than 6500 rpm. As your rpm increases, your clearance should increase. If you’re revving to 8500 rpm, you probably want on the order of .125” to 150” on intake/exhaust to be safe.
__________________
TeamCaffeineGT
Member
Ensure you use thread sealant on the bottom head bolts as well. Some of these bolts go into water jackets and require sealant.
Similar threads
