|12-19-2012 02:54 PM|
35 tall tires/4.11 gears/turbo 350 transmission/2800 pound car/6500 rpm
first gear=66//second gear=109//third gear=165
first gear=52 ///second gear=87///third gear=132
|12-19-2012 12:06 PM|
Unless you got and will run a 25" tall tire the 4.11's are useless on this combo.
35" tires need a 5.13 gear minimum ( not less than)
a 5.57:1 ratio is just right for this combo with 35" tall tires.
the hot rodded 305 needs to rev to make its power.
|12-19-2012 11:57 AM|
The amount of actual chamber de shrouding is very very small. and its not where you think it is.
A very minimum of metal removal is all that is nessessary in the chamber to fit the larger valve.
These heads can be flat milled to a finished 51cc when all done. The physical limit is the spark plug boss and edge of the 1.94" intake valve seat.
CC the heads after rework/before milling for compression.
they will end up around 62cc when all done. CC and mill as required.
use a thin .015" felpro 1094 head gasket
Does this 305 have a flat top w 4 valve relief piston (L-69 motor) or a dish piston in it?
ya it matters. that 218deg cam needs compression.
you do not need to get all carried away with deshrouding on this head.
Use a drill bit to "gauge" the chamber wall to stock valve edge clearance, when the valve is partally open. Compare the to the larger new valve.
(.050" bigger valve radius) don;t get carried away. This is not a hi flow area. most of the flow is directed towards the spark plug in the chamber, on a SBC head. On this motor you need the compression ratio more than the chamber flow improvment.
Do not get carried away deshrouding.
Thats the whole point of just going to a 1.94" valve on this head.
flow your garden hose thru the intake port to see the flow pattern.
|12-19-2012 11:46 AM|
305 ho cam
After you finish the porting on your heads and deshrouding the 1.94 valves make sure the chambers are 58cc. With 58cc chambers and the .015 thick head gaskets your static compression will be 10.0 and with the Comp cam the DCR will be 8.3. Is there any way to run shorter tires to get the benefit of your 4.11 gears?
|12-19-2012 11:20 AM|
worth the upgrade. The holley 300-36 is another good one.
Once the cylinder heads are nicely ported the motor likes extra valve lift.
So if you happen to trip over a set of 1.6 ratio SBC rockers, they will help.
.484" net lift with your cam. (don;t loose sleep over this)
(The push rod slot in the head needs to be extended a bit towards the rocker stud)
|12-19-2012 11:19 AM|
If you want it to be really different and unique build your self a set of 180 degree headers.
Makes any V8 sound like a Ferrari V12. and makes great power too.
Your buggy chassis allows you to do this.
the primary pipes from cylinders #3, #5, and #4, and #6 cross over and join to the header collector on the opposite cylinder bank. The pipes do not need to be equal length.
|12-19-2012 11:16 AM|
|buggy305||sorry didnt see your last post thank you|
|12-19-2012 11:14 AM|
|buggy305||thanks for sharing those articles and all your input i am going to go with the 1.94 valve then go at porting them im sure if i do lots of reaseach and put the time into it i will be happy with the results...one other quick question sence my motor is going to want to rev should i ditch the performer and move up to a performer rpm air gap intake ?|
|12-19-2012 11:09 AM|
keys to making this work.
Finished compression ratio. (10:1 or as close as possible to it) Head milling. piston choice, gasket choice
head port flow (220++intake 160+ex cfm @28") generous real effort complete home porting+ larger 1.94" intake valve ans a good valve job) use a felpro 1205 as a guide and get serious with the die grinder, especially on the roof of the port and around the guide in the bowl. you need at least 1 long shaft carbide burr to get deep in the intake port.
cam (the cam yu got is good)
valve springs ( so it can rev)
RPM hi rise dual plane intake (power)
gears (5.57 is just right for a 35" tire for this buggy)
converter 9" 10" 3000+ actual stall (3500+ advertized stall)
headers with a collector (power and torque)
|12-19-2012 10:51 AM|
here is another one. This one has a big big cam in it but the idea is the same.
The power band is way up there. You got to rev it up. ( gears)
this is the nature of small cube hot rodded SBC's whether 283-302-305 or 307 or even a 327.
|12-19-2012 10:47 AM|
look at the power band of this hot rodded 305. it wants to rev.
6000++rpm. needs serious gears.
your modded 305 is going to be much the same.
|12-19-2012 10:38 AM|
Porting with the stock 1.84" valve will improve flow for sure but porting + the larger 1.94" valve (with a new valve job) will make more flow, cause the valve is just bigger.
The 1.94x 1.60 valve combo is for a ported 305 head on a 350 motor.
The modded (cam etc) 305's power band is going to be much higher rpm than the stock motor.
It wants to rev. (Gears, converter) with 35" tires you will need some serious gears. It will be lame with the wrong gears.
A hot rodded 305 SBC becomes just as much as a high rever as a 302SBC is famous for. wants serious gears to perform/
The long stroke has nothing to do with it.
If your headers are "zoomies" convert/modify to a long tube style with collectors. ( more power/more torque)
|12-19-2012 10:30 AM|
|buggy305||will i be alot better off with the 1.94 valves and porting with a farly mild cam as opposed to porting the stock 1.84 ? ive been doing lots of reading on porting the last couple days and i think im going to give it a try there really only is one way to learn|
|12-19-2012 10:28 AM|
One good way to get a 305 to outperform a 350 is to supercharge it.
Needs air flow too. (DIY porting really helps)
a 142 blower is very very effective on a low compression 305.
A low compression ratio is one of the keys. ( (70++cc) large chamber 350 heads *1.94x 1.50 valves on a dished piston 305)
high perf engines make more power by increased air flow. Not by increased $$$ flow.
|12-19-2012 10:16 AM|
You are talking through both sides of your mouth.
Seems as long as you don;t have to invest effort, its alll good. (porting your heads)
Do not use 1.6 valves on those heads on a 305. just 1.50' but the 1.94's will help (with porting)
You can simk all the money you want in it, but the poer of the 305 will be limited by the stock heads.
Money won;t fix that. But effort, will.
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