Chevy Springs Mod + Port/Polish Qs
- Thread starter theKnifeArtist
- Start date
okay so i ran into two problems today.
one is the picture shown.
is that thing also called a retainer? well its the little metal cup that goes in first that the valve spring sits in. i noticed the valve spring has a tight fit in this cup unlike the stock spring that sits in it. if i give it a little motivation, i can probably have it sit fine, would this tightness be something to be worried about?
two: i bought a valve spring compressor from napa. unfortunatly i didnt pick the right one. this is the one i bought.
http://www.sjdiscounttools.com/lis16750.html
this grabs the lower coils of the spring and the top and compresses it. i now realized that the bore where the spring sits goes up high so the tool can't get in there. Fuck.
one is the picture shown.
is that thing also called a retainer? well its the little metal cup that goes in first that the valve spring sits in. i noticed the valve spring has a tight fit in this cup unlike the stock spring that sits in it. if i give it a little motivation, i can probably have it sit fine, would this tightness be something to be worried about?
two: i bought a valve spring compressor from napa. unfortunatly i didnt pick the right one. this is the one i bought.
http://www.sjdiscounttools.com/lis16750.html
this grabs the lower coils of the spring and the top and compresses it. i now realized that the bore where the spring sits goes up high so the tool can't get in there. Fuck.
Attachments
Yup, that's how mine fit, with the retainers in the head, i just drop the spring in straight, then compressed it down real quick, and they seat themselves quite nicely 
I used the Snap-on tool, you can use it to remove the springs too, just instead of using the magnetic end bare (it's too wide to fit) you can just put a socket on it, the magnet will hold it in place, use a rag or shop towel like IJ. instructs, then tap away!
I used the Snap-on tool, you can use it to remove the springs too, just instead of using the magnetic end bare (it's too wide to fit) you can just put a socket on it, the magnet will hold it in place, use a rag or shop towel like IJ. instructs, then tap away!
for future reference, i tested the stock valve spring pressure at typical valve lift. it came in around 70lbs. its easy to get the stock coil springs to bind compared to V8 springs.
my friend who ownes a commercial building w/ several bays rents one out to a race car redneck guy. he had some BBC outer springs. he said they were comp cams titaninum somethings... i couldnt get that thing to compress more than 1/4" by hand!
also, for the record, too HIGH Of a valve spring pressure CAN hurt things. i dont remember who said it wouldnt hurt but im not going to the previous pages to find out. too high of a valve spring pressure can accelerate cam wear and eventually wipe lobes. excessive spring pressure can also tulip the valves as well as hammer the seats into the head. the goal is to run as LITTLE valve spring pressure as necessary to preclude float and overcome the inertia of the valvetrain harmonics at elevated RPM's. (not forgetting the effect of increased boost pressure on the backside of the closed intake valve <edit IJ>)
if you are border-line on the limits of valve float, you can buy yourself more headway by simply changing one or more things; lighten the valvetrain mass, increase spring pressure, reduce peak RPM, reduce aggressivness of cam lobe profile.
all of those choices have pros and cons..except the part about reducing the valvetrain weight/mass!
stock springs will perform better by simply changing over to shim-under-bucket and Titanium retainers. unfortunatley, this will only take you so far before you HAVE to increase spring pressure to accomodate more aggressive cams.
it doesnt seem like the BBC inner springs are too insane though. they are only about 20% greater than stock which, combined w/ Ti retainers, ought to perform very well. i think im going to pair the BBC inners up w/ some BC retainers and BC stage 2's/264's for an upcoming motor build
my friend who ownes a commercial building w/ several bays rents one out to a race car redneck guy. he had some BBC outer springs. he said they were comp cams titaninum somethings... i couldnt get that thing to compress more than 1/4" by hand!
also, for the record, too HIGH Of a valve spring pressure CAN hurt things. i dont remember who said it wouldnt hurt but im not going to the previous pages to find out. too high of a valve spring pressure can accelerate cam wear and eventually wipe lobes. excessive spring pressure can also tulip the valves as well as hammer the seats into the head. the goal is to run as LITTLE valve spring pressure as necessary to preclude float and overcome the inertia of the valvetrain harmonics at elevated RPM's. (not forgetting the effect of increased boost pressure on the backside of the closed intake valve <edit IJ>)
if you are border-line on the limits of valve float, you can buy yourself more headway by simply changing one or more things; lighten the valvetrain mass, increase spring pressure, reduce peak RPM, reduce aggressivness of cam lobe profile.
all of those choices have pros and cons..except the part about reducing the valvetrain weight/mass!
stock springs will perform better by simply changing over to shim-under-bucket and Titanium retainers. unfortunatley, this will only take you so far before you HAVE to increase spring pressure to accomodate more aggressive cams.
it doesnt seem like the BBC inner springs are too insane though. they are only about 20% greater than stock which, combined w/ Ti retainers, ought to perform very well. i think im going to pair the BBC inners up w/ some BC retainers and BC stage 2's/264's for an upcoming motor build