Valves Hitting The Pistons??

gxnos · Dec 25, 2003

i have a quick question. i am lazy and i really dont want to check my piston to valve clearance before I start my new engine.

I have the eagle 331 kit with SRP flat top pistons. they have really big notches in them too. with any common sense during engineering, i would assume they build these pistons to accept high lift cams to be compatible with many different heads. I have a 560 lift cam with 248 duration and world sr heads with 2.02, 1.60 valves.

do you think that valve clearance would even be an issue?

thank you in advance

Stang6911 · Dec 25, 2003

You wouldnt think that it would have problems but i really wouldnt say its gonna be fine. I know the better safe than sorry applies here. Its alot of money to just take a guess. My opinion would be to check it so you know you are safe! But if you want my opinion on if it will clear......It should.

RIO5.0 · Dec 25, 2003

Do you really want to chance there may be an issue??? Looks like alot of $$$ there...At the min, i would undo a set of valve springs and do the "drop valve" method....for nothing more than peace of mind... Maybe an hours time and you'll have your answer...its not that hard...

gxnos · Dec 25, 2003

RIO5.0 said:
Do you really want to chance there may be an issue??? Looks like alot of $$$ there...At the min, i would undo a set of valve springs and do the "drop valve" method....for nothing more than peace of mind... Maybe an hours time and you'll have your answer...its not that hard...

but i already got the heads torqued down! ::headache::

gxnos · Dec 25, 2003

i had a friend that had a flat top piston with no notches with an Xcam (542 lift). he checked the clearance and there was about .010" of room. the engine ran but i swear you could hear the valves kissing the pistons. i think im gonna be ok though with those big notches in my pistons. check out this pic of my shortblock!

http://images.cardomain.com/member_images/1/web/121000-121999/121330_41_full.jpg

Stang6911 · Dec 25, 2003

Doesnt matter how big they look, better check it while its out, your risking alot of money over 1 hour of work and a 10 dollar head gasket!

RIO5.0 · Dec 25, 2003

gxnos said:
but i already got the heads torqued down! ::headache::

Thats fine for the method i suggest...take #5 its easy to access....pull the plug, rotate the motor til she's coming up towards TDC...stop, stuff some nylon rope in the hole, bout 12" worth or so...now roll the motor til you feel it stop..thats the rope hitting the valve....pull the spring/keepers on Exh or Int....run some electrical tape around the top of the valve...that'll keep it from falling into the cylinder(sorta of safety stop)...back your wrench off....pull the rope out...rotate the motor up til your at TDC, drop the valve to the top of the piston..mark the valve with something....then lift it up to the seat and remark it....the distance is PV clearance...roll the motor thru a couple turns and recheck...HOLD THAT VALVE UP THOUGH WHILE YOU ROTATING. Do the other valve...its better than not checking at all...I believe its 10 degrees BTDC and ATDC are the danger zones. There are websites that give the specifics on the "crash zone"...thats were i found my info, as i was all TQ'd to...
i did mine this way and had plenty of room...least i knew i was safe...

Hope it helps some...

Valves Hitting The Pistons??

gxnos

Stang6911

RIO5.0

gxnos

gxnos

Stang6911

RIO5.0

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