small block tricks

[daveashsr]

hi guys i've asked this question before but lost the e-mails !! who out there is blocking the center of the block over the cam ? is there any hp gains and what about oil return ?? i'm putting my 360 back together and if i can sneak a couple hp in there i need to do it !! i run restricted class 2bl cast heads 194 160 valves 500 cam no porting any help ??

[9dodge]

The one thing I would consider doing is to go to a thinner valve stem. We do it in our 318 motor. We use a 5/16 valve stem, or you could do a 11/32. Just get rid of the big stem. You will pick up CFM and that equals horsepower.

[Dirt Track Dodge]

If I was to do a 360 restricted I would try:
std 4.04 73' 340 pistons,(if no comp.limit)
the piston will be out about .080,depending on heads,may have to cut .020 or .030 off top of piston. Top ring will be .150 down.Bevel edge of piston with flap wheel until engine will turn over w/o bumping head up during test assembley.With FelPro gasket installed, piston to head clearance will be .035-.038 .
This gives the chamber a more complete burn,otherwise there will be unburned fuel in the squish area and with a 2-bbl their's not much to waste. If 9:1 or flat top only,then
zero deck with 71' 360 pistons and have Huges
weld and mill heads to get rid of squish area
Could use chebbie -22cc blower pistons w/327 pin ht,bush down rods or open up pistons to fit pins,Magum heads have efficient chambers,
stock-flow209@.500 int/176@.500 ex. they use small valve stems,have to re-drill intake holes,useAMC lifters,factory 1.6rockers,sink exhaust valve .010 below intake to help cut down on fuel charge going out the pipe on overlap,salvage yard price appox. 300.00 .I don't know how much RPM valve train can take? Maybe someone could comment on these ideas? Also could try
quick ramp cam that Engle grinds for Hughes,
it takes advantage of .904 Mopar lifter.
RockerArm Specialties-530-378-1075 ask for
Gary,he can change 273 rockers to 1.6,about 6.00 a rocker,with
the big lifter and high ratio rocker- valve acceleration off the seat gets close to that of a roller.Moroso makes a pan for lifter valley ,don't know how much power it's worth
use stainless shim stock or special intake
gaskets to block off heat crossover,eletron-
ic distributor,can use only one Hemi spring
that way the weights will pull in enough to start the engine,then go to full advance, which works good for restarts, 2-bbl engines
tend to work best with lots of timming(36-40)
lean jet(light gray),and hotter plug w/projected core.I've run these combinations
by slowly working towards these limits.
Another trick,if you have to run a hyd. cam,
is to set your lifter preload at the bottom.
If at the top,you could pop the snap-
ring out.There's no such thing as a Anti-Pump
up lifter,the hyd lifter is only as good as the
valve spring controling it.Crower and others
have proven that at the upper RPM levels the
hyd lifter starts to collapse and you will
lose lift,power can drop as much as 20 hp.Set lifter preload at .005 from the bottom of it's travel.
Would like to hear comments,good or not so good.

[340king]

I would use and currently am using Ferera 1.94" Chevy pro-stock undercut valves. These valves are 11/32" on the stem and are necked down to 5/16" in the port. They are .100" longer than stock to fit the Mopar length. Cut the length of the valve guide protrusion in the bowl, this really makes a difference and is normally not considered porting.

Sanborn was the guy that talked about sealing the lifter valley holes to reduce oil splash on the crank. This also helps keep hot oil from spraying on the bottom of the intake, which is important to you with a stock intake having a common valley cover and plenum floor.

Are you using the offset carb adaptor that centers the carb over the secondary ports for less restriction?

I would use a tight lash cam from either Ultradyne, Reed or Crower. These cams are designed to work best with 2 bbl, restrictor plate or low compression engines. They really work. Both Ultradyne and Reed offer .904" lifter diam. designed versions of this cam, I don't know about Crower.

What compression ratio do you run? Are you running gas? VP may have a fuel that can pick up some HP.

[340king]

This is a response given by Sanborn to questions about oiling a small block. It is posted on the subject "SMALLBLOCK OILING 360 IMCA MOD" or something like that.

"We have used SB in dirt late models for years. I know our applications are different but maybe this will help!
The stock oiling system works well up to 6500. I recommend 1/2 groove main bearings. Check the oil passage
alignment between the rear main cap and block, remove any restrictions. At 7000, install a freeze plug in the
left side lifter galley, drill 1/8" hole to allow some oil to pass. Drill .080" holes in the top two camshaft retainer
plate holes to oil the chain. Cover the camshaft slots in the block to keep excess oil from getting on top. At
7500, oil the rocker shafts externally by tapping in the back of the head. Block off any oil to the head,
restrict oil to the cam bearings. Elongate the oiling hole in the bearing ( make it into a slot 1/4" wide X 1/2"
long ). Enlarge the oiling passage in the rear cap and the vertical passage in the block. Round all corners if
possible. At 8000, use a dry sump pump. Above 8000 there are more mods required. A couple of general
suggestions; we always used the Melling High Volume pump with a dual pickup. There may be other brands as
good now on the market. Never restrict oiling to the rocker arms. Check your camshaft oiling holes. We have
found some where the oiling holes would be open to the oiling passage at the same time as the main bearing.
If this happens you have a flow drop to the rod bearings. The only fix for this is to oil externally to the rocker
arms or get another cam. I could go on all night about oval track oiling the SB. A lot of this info has been
around for years but has never been passed out".

[This message has been edited by 340king (edited January 26, 2000).]

[daveashsr]

wow u guys are great ! i didn.t know u would post so quick !! thanks !!
now the rest of the story !!
i should have told u more about my eng ! sorry! i use ross pistons in it with a raised pin ht so i am zero deck ht now and if i could get 57 cc out of the heads it supposed to come out to 12-1 ratio !! thats with 020 head gaskets ! the motor was reall strong but broke rear main cap so i'm having to redo it ! the ferra valves sound like the way to go in the heads! how close can i cut the guide off ?? can i cut it flush ? i do use a slide type carb adapter and usually run it center so i'll try moving it back ! u say center it over the secondary holes ? i also already have the morso valley pan but was wondering if i would be better off blocking it off as the plate may be illegal but might get away with the blocking don't know !! how do they make the 273 rockers 1.6 ? ofset bushings ?? how much additional lift will that create ? i have to watch out for my valve cl with the heads cutand zero deck ! would like sug as to what heads to use 2 ?? have several casting ## anyone tried diff one ? thanks again david

[Trat]

If you use the Magnum heads, and are using a stronger valve spring... probably a good idea to replace those little stock rocker arm studs with the chevy H.P. stuff you can get at the speed shops.

I like the Hughes cams, too. Best cams I have ever raced with.