mw66nova

iTrader: (13)

i'll be running the xe274cam with these heads. the lift on the cam is .487/.490. will i have to cut down the guides or anything?

Ukraine Train

I ran those heads with an LT4 HOT cam (.492/.492 lift) and had the guides milled .100". I would assemble the retainer and keepers on one installed valve and measure the clearance to the guide if I were you.

five7kid

iTrader: (14)

...and seal...

You should have at least .060" more travel than lift to be safe.

Ukraine Train

Good call, I forgot to mention the seal.

mw66nova

iTrader: (13)

ah jeez. this is too complicated. i'm just going to take it to the shop, get some new springs and seals, and tell him to make them good to at least .510" i'm running outta time here and don't know if i'll have time to dissassemble, then reassemble.

Ukraine Train

you only need to measure one valve. shouldn't take more than 20 minutes

Rob Wade

Hey....what happened to the 396 BB??????

mw66nova

iTrader: (13)

deal fell through...don't worry, i'll have a bb eventually.

mw66nova

iTrader: (13)

not exactly sure what to measure though, or what to measure with...anyone think i can get away with the stock valve springs?

Supervisor42

Best way to measure retainer to guide clearance is to use the "lite-spring" method. Spring up the valve with a spring out of an old mastercylinder or an old fuel pump. Roll the cam to the top of the lobe (max lift) then with a dial indicator on the retainer, press the rocker arm until it bottoms on the guide. Note the travel is the extra clearance. If it binds up before max lift you have negative clearance and congratulate yourself for not tearing up a bunch of rockers and pushrods.
Stock springs with a high lift cam: You can get by with them if you don't mind seeing an occasional valve head buried in the top of a piston or install a rev limiter that will limit rpm to below 5500. (well below the cam's peak horsepower)

mw66nova

iTrader: (13)

hmmm....screw that! i don't know that i have the equipment to do this at this point...and my machinist will do all of this for me for a VERY low price...

Damon

Springs that will drop right in without machining and take up to .500 lift with correct pressures that match a mild street performance cam: Crane 99848 or Comp 981.

Retainer to guide seal clearance measuring: Assembly a valve just like you normally would but don't put the spring in- retainer and locks on the valve but no spring in between. Pull up on the retainer to seat the valve and the locks. Use an outside measurement caliper to measure the distance between the bottom of the retainer and the top of the guide seal. That's your max lift before you start slamming those parts into eachother (having an extra .050" of clearance beyond your max lift is highly recommended). You don't need a very accurate caliper for this as you really only need to know down to the .01" level, not down to thousandths of an inch. You can pick up a cheap plastic combination caliper at Lowes or Home Depot for about $10- it's plenty good for this kind of work.

Do at least one intake and one exhaust- sometime clearances are different between them. Stock 113 heads I measured a few years ago had about .480" clearance with the stock retainers and seals in place. If your heads measure the same as mine did that's too tight for the cam you have chosen.

five7kid

iTrader: (14)

Cutting the guides for positive seals usually gives pretty good clearance. My machinist said mine are good for .560 lift with just that being done (stock-type valves, retainers & keepers). You aren't going with that much cam, so I'm sure your head shop can get you set up with minimal issues.

Now, the real rubber-meets-the-road issue: Are you still planning on the porting work? Nothing has changed from your previous head plans, you know...

mw66nova

iTrader: (13)

over the 083 heads? after tons of research, i've found that stock for stock, the 113 heads outflow the 083 heads by like 40cfm....and the exhaust side is MUCH higher.