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-   -   305 ho cam (http://www.hotrodders.com/forum/305-ho-cam-227117.html)

buggy305 12-12-2012 08:16 PM

305 ho cam
 
im trying to decide on a cam

305 bored .40 over flat tops, ported 416 (ho) heads edelbrock performer intake, geting a 650 edelbrock carb not sure if its to much carb but geting it cheap so gonna try it, th 350 transmission, 4:10 rear gears, 35inch tires, and a guess around 2800 pound rig. and someday down the road maybe a 75 shot of nitrous

this is the cam i was thinking about Lunati Bracket Master II Cam and Lifter Kits 80350LK - SummitRacing.com. thanks in advance for any response

not switching to a 350 i no i could make more power for the same money but i got this motor out of a smashed truck for dirt cheap

F-BIRD'88 12-12-2012 08:44 PM

Not a lot of gear for a 35" tall tire. Perf 305's need gears.

Not enough info on the car/combo and purpose.
what is the engine compression ratio? transmission converter stall speed.?

Just look at what you have shown (limited info) it looks like this combo will not have near enough gear ratio
for the tall 35" tires. Needs a 5.13 to 5.38 gear and a "10" 3500 stall converter"
(the actual converter stall will only be about 3000 rpm when behind a 305CID motor) (about 500rpm LESS stall speed than advertised)

The 650 carb is none too big. a 750 edelbrock is not too big.
Get a Performer RPM hi rise dual plane intake manifold.

Then I see that cam working well in this 305 motor and the 305 giving very impressive performance.
Getting the gears and converter choice right is critical to making the hot rodded 305 work.

Use a thin .015" head gasket to get the compression ratio up. (felpro 1094)
Cammed 305's like compression. Cammed 305's like to rev. (especially when the heads are cleaned up) Get some Lunati 73943 springs ( or equal) and shim to correct height. 1.70"

gearheadslife 12-12-2012 08:51 PM

compression to high for pump gas..
58cc heads on a flat top piston..

vinniekq2 12-12-2012 08:54 PM

Quite a mild cam. Have you figured out your CR yet? tall tires? what kind of car?nice and light though

F-BIRD'88 12-12-2012 09:02 PM

Quote:

Originally Posted by gearheadslife (Post 1622169)
compression to high for pump gas..
58cc heads on a flat top piston..

its a 305. the cr will not be too high. More likely too low

don;t assume the finished chamber is 58cc either. especially if you installed larger valves and or did chamber work.
They usually end up bigger (62+/-cc)

60cc and a .041" gasket will result in not enough engine compression ratio on this 305 combo.
You want it around 10:1. measured for this camshaft ...Use the thin 1094 gasket.
(.025" piston deck clearance) (92 octane gas)
The success of the combo depends on getting the critical details right.

gearheadslife 12-12-2012 09:08 PM

Quote:

Originally Posted by F-BIRD'88 (Post 1622174)
its a 305. the cr will not be too high. More likely too low
You want it around 10:1. for this camshaft ...Use the thin 1094 gasket.

yes it's a 305, a ping prone 305

my 9.6 crossfire head l82 camed 305 pings like crazy.. on anything lower than 94 pump fuel

F-BIRD'88 12-12-2012 10:35 PM

Quote:

Originally Posted by gearheadslife (Post 1622176)
yes it's a 305, a ping prone 305

my 9.6 crossfire head l82 camed 305 pings like crazy.. on anything lower than 94 pump fuel

Its out of tune.
This is not a stock crossfire motor. Do not equate it.

try some Champion RV8c plugs in your crossfire 305. and fix the tune. its out of spec and or sucking oil in or he EGR system is faulty

buggy305 12-13-2012 02:11 PM

thanks for the responses... i jumped the gun got a good deal on a comp cam and lifters 218 218 at .50 454 lift 110 lsa. its a pipe buggy mainly for sand/mud drags but i will do some touring around old woods roads and trails..stock torq right now but will be geting a stall torq i was thinking a 3000 stall but i didnt no they where usally 500rpm less then what there advertised, as for compression ratio im not sure the heads are comin off hopfullyy this week and going to get checked and get new springs and i will be buying that gasket you recommended. the heads have stock valves no bowl work i just basically ported it to match the intake gasket ( first time playing around with porting just trying learn )

F-BIRD'88 12-13-2012 02:27 PM

Thats not porting. What you did added nothing... You need to get in there deep and really port those heads.
Do the whole port, bowl, guide boss contour,etc . then port match to a felpro 1205.
best with 1.94 valves added too.
Like this:
http://www.hotrodders.com/forum/atta...3%20%20chamber
These heads work prett good when correctly completely ported. Don't be shy.

Converter: yup if you want a real 3000 stall behind a 305 get a "3500+ stall converter"
or you will come up short. The 305CID motor makes less torque than a 350 does. The real WOT launch stall you see
from a converter is relative to the engine torque output applied. its approx 500rpm difference between the 305 and 350 cid
so don;t be shy with the converter.
The cam is fine.... get the right stall converter and can use more gear with the tall tires for sure.
Converter and gear ratio choice is critical to making a 305 work for you. Thats where most people get it wrong.

F-BIRD'88 12-13-2012 02:48 PM

For, with that 218deg .454" lift cam a 9" or 10" converter rated at 3500 to 4000 stall (advertised) and some 5.38 gears
will be the right choice, with 35" tires.
Don't be shy on the heads. Compression and port air flow are your friends.
The distributor will need a recurve too , with that cam.

You will see how good a 305 SBC can and will perform.

Can use up to a 150hp nitrous system. Now you will smoke some $$$"stroker motors"$$$

gearheadslife 12-13-2012 05:37 PM

Quote:

Originally Posted by F-BIRD'88 (Post 1622220)
Its out of tune.
This is not a stock crossfire motor. Do not equate it.

try some Champion RV8c plugs in your crossfire 305. and fix the tune. its out of spec and or sucking oil in or he EGR system is faulty

it's not "out of tune" it's in perfect tune.. wideband data loged..
the timing and ccc q-jet are spot on.. factory correct...
with proper a/f % under all loads and rpms
factory 305 in a SS with 8700 miles

buggy305 12-18-2012 04:46 AM

thanks for your input fbird88 i think im gonna stay away from the porting as im not really sure and dont wanna screw them onless anyone can suggest a good book or artical or video to help me get started

vinniekq2 12-18-2012 08:05 AM

did you make any decisions yet?curious as to what transmission you use in your buggy? I understand the desire for low end torque for off road use. Is mileage a concern?what do you use for exhaust?

F-BIRD'88 12-18-2012 09:05 AM

Quote:

Originally Posted by buggy305 (Post 1624024)
thanks for your input fbird88 i think im gonna stay away from the porting as im not really sure and dont wanna screw them onless anyone can suggest a good book or artical or video to help me get started

Articles: There are some online articles by David Vizard on porting cylinder heads.
The basics of the SBC is covered. Do a google search.

Books: Again search Amazon for books by David Vizard. There are many.
Some specific to porting SBC heads.

Here is one of a series of 10 articles to get you started.
You do not need to be a expert to get good results on these heads.
But you do need to get in there and get dirty.
http://www.eurospares.com/graphics/e...he%20Time!.pdf

the rest of the 10
http://www.eurospares.com/graphics/engine/Vizard/

Not porting your heads will result in lame poer reguardless of how much cam you stuff in it or other mods you add.
Engines need air flow to make power.

buggy305 12-19-2012 10:46 AM

it has a th350 newer then 81 (has the eltric plug in ) i bought a cam 218 218 at .50 454 lift 110 lsa trying to decide on going with the 1.94 / 1.60 valves and 3 angle valve job but i dont really want to sink a whole bunch of money into a 305.. mileage is not a concern as it is only for offroad use for exhaust i run upright headers one pipe for each cylinder straight up not sure how they compare to long tube headers performance wise. as for rear gears torq etc i havent decided 100 percent on anything yet


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