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Author Topic:   Best 305 I can build
5tbone
Dirt Full Roller

Total posts: 58
posted April 25, 2005 06:22 AM  
I want to build the baddest 305 I can build with these rules applied any suggestions


3. Engine: Steel block and heads only. No late-model production heads on Chevy's. Flat-top pistons only. Cast iron intakes only. No Bow-Tie. All accessories must be driven and mounted off the front of the engine. Roller rockers ok.
Motors Allowed:
Chevy 305 +0.030 overbore
Ford 302 +0.060 overbore
Dodge 318 +0.020 overbore
Min.-17 inch Vac at 1,000 RPM


5tbone
Dirt Full Roller

Total posts: 58
posted April 25, 2005 03:01 PM  
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BrianW
Dirt Freak

Total posts: 385
posted April 25, 2005 03:33 PM  
Well, given the brief rules and not knowing what the other restrictions are here goes...

Use the 305 HO heads (camaro/firebirds), angle milled to the max to gain compression, clean up the ports, run undercut oversized valves, run a lightweight flat-top 2-VR piston with 6" rods that have been lightened and polished, run an ultralite 305 crank, bore it the max (since the max is .030), run the marine 4bbl high-rise GM intake, call a cam grinder to get a custom cam for that vacuum rule...


5tbone
Dirt Full Roller

Total posts: 58
posted April 25, 2005 07:15 PM  
this is the only other rules they give.
but they will puff the engines at there discretion. so the rest is all interpretation


4. Carburetor: Working Vacuum secondary 4 barrel. No squirters on back barrels.

jpotter94
Dirt Forum Racer

Total posts: 94
posted April 25, 2005 07:24 PM  
take my advice and you will have a WICKED motor..take a 305 block,bore it .030 over,put oil restrictors in,grind or paint the lifter valley,install vent tubes in the lifter valley,grind every edge of the block(this is where they are prone to crack) have it decked to zero,line bored,squared ect..install a lightweight forged 327 or 283 crankshaft,eagle 6'' h-beam rods and a set of light forged d-dish pistons..call HOWARDS camshafts and have a cam made for this setup,use a merzinski undercover intake,the 305 4 barrel heads,have bigger valves put in them,bigger springs,screw in studs and guidplates and angle mill them .10 thousanths.have them pocket ported and port them on the intake and exhaust side if you can,roller rockers,hardened pushrods.take a good 750 vacuum secondary carb and have c&s build it for you.all of this would make one wicked motor,we had a 305 sprint motor with these specs and it ran amazing.it sets in a b-mod now that wins quite a bit anywhere it runs.if you wanna get serious i could build it for you..good luck,hope this helps!!

5tbone
Dirt Full Roller

Total posts: 58
posted April 26, 2005 06:24 AM  
if I wanted to build this exact to your specs what kinda $$$$$ would it take and do you know where I can get all these parts?

Thanks for any info.

jpotter94
Dirt Forum Racer

Total posts: 94
posted April 26, 2005 08:37 AM  
if you do it yourself and just have the machine work done you could do it for around probably $3500-4000....the rotating assembly balanced you can get most anywhere for around $1400..the heads will cost about $500 to get done..you can do all the blockwork except the boring,decking,squaring ect,that will be about $500 as well.putting in and grinding everything you could do..most of the parts you can get from most any supplier like speedway,jr motorsports,midwest motorsports,the best place is competition products..if you dont think you could do any of it,and are relatively close we could build the monster for you for about the same price,the motor with what i have said as long as you keep the maintanence up would be pretty well bullet proof.would last a few seasons easy with good maintanence..what will this go it..also plan on turning this thing in the 8000 rpm range easy!

nice_guy_wi
Dirt Maniac

Total posts: 120
posted April 26, 2005 09:21 AM  
Ok I will bite......what are the proposed hp and torque numbers for this 305 turning 8000 rpm?

19J
Dirt Freak

Total posts: 370
posted April 26, 2005 11:17 AM  
A 305 bore 3.740 std with a 3.48 stroke. A 3.770(.030 over) with a 327 crank 3.25 is a 290 ci. Not a 305. My version of it is. How clear are the rules. It says 305 block .030 over so bore it .030 over and stick a 400 crank in it. But thats "cheating" A lot of ways you could do this. I would focus a lot in the heads. Get a good set of flat tops like srp or something and a GOOD set of rods. Brian and Jpotter both have good ideas.

5tbone
Dirt Full Roller

Total posts: 58
posted April 26, 2005 11:27 AM  
See all of it is vague. the track uses a puffer(hose in spark plug hole release the rockers and a plunger in a PVC tube) measures something but I don't know what.

Does anyone know what this measures? that is really what they use to see if it is legal. if you know what a puffer is then what effects the results pistons, crank, rods,exactly what.

thanks

jpotter94
Dirt Forum Racer

Total posts: 94
posted April 26, 2005 01:06 PM  
i would say a puffer is a rig they have to measure cubic inch and compression,cylinder volume..19j is right on my version being a 290,and the reason i say to do it is this is a big bore short stroke setup for a 305 and it works very nicely on tracks from 1/4 to small 3/8 mile tracks..

niceguy--it wouldnt be uncomon to see this setup pull 475 to 550 hp and and about 470 ft lbs of torque and on up just depending on what all is used and done..now i said 8000 rpm but trust me it would turn well over that if you wanted to but i would say over 8000 and you'd be out of the rpm range,rpm range may be lower depending on the cam maker.this motor is similar to the 331 that everyone like don klien and ect used to run and turn 9500 on 1/3 mile track.we used this setup cause were mandated to the 305..it is now in a b-mod and does well against 383 and 406 at our local small 1/3 mile track..

Eljojo
Dirt Forum Champ
Total posts: 968
posted April 26, 2005 04:23 PM  
OK....first off the "puffer" is a "P&G". It will tell the displacement within a few cubes. Easily spot a 327 from a 350 or a 377 or 383, but I seriously doubt if the user will be able to spot a 290 from a 305. The operator will be figuring temps and gasses emitted and PROBABLY not question your displacement.
It's been my opinion that these big bore, short stroke mills work well with lighter cars, not with 3300lb street stocks.
Question: could the block be sleeved and get to .060 over and get closer to 305 cid? Could this guy use a 307 block and deck it and come very close to 305? (same 3.25 stroke) only much cheaper!What makes the 269? Isn't that a short stroke motor with a small bore?
How about a 305 block, installing a 3.48 light weight crank, good pistons and rods, a custom grind cam, go with the Brezinski intake and 041 heads. Then he's got a legal motor that makes a ton of power.
I'm no motor guru, I may be way out in left field!

5tbone
Dirt Full Roller

Total posts: 58
posted April 26, 2005 04:52 PM  
My class is an E-mod class the lightest the car can be is 2400 after feature. These are all good Ideas. The track is a small 3/8. I want to be legal yet lethel at the same time.
any more ideas would be great thanks for clearing up what puffing an engine means.

THOR
Dirt Newbie

Total posts: 1
posted April 26, 2005 07:29 PM  
do your rules state u have to use a 305 block? if not use a 350 4" bore 3" stroke crank. 302 cid. bad to the bone.

5tbone
Dirt Full Roller

Total posts: 58
posted April 26, 2005 08:34 PM  
I hope this isn't a stupid ? but how do you tell the dif between a 350 and a 305 if you don't use a "puffer"? if that is the only way to tell then I don't know why I couldn't use a 350. But motors are not my strong suit.
thanks in advance

speedy46
Dirt Maniac

Total posts: 165
posted April 26, 2005 08:39 PM  
the serial #'s will be different

5tbone
Dirt Full Roller

Total posts: 58
posted April 26, 2005 08:45 PM  
Well our tech guy isn't hitting on all cylindersso he prabably wouldn't catch that.

jpotter94
Dirt Forum Racer

Total posts: 94
posted April 26, 2005 10:55 PM  
first off if you use my combo it is LEGAL..it is a 305 block and .030 over bore..there is no rule on stroke or so you didnt say there was..second a 305 and 350 are the same stroke.you cannot go by the serial numbers to tell the difference between the two because they make a 3970010 350 and a 3970010 305.the bore of a 305 is 3.75 and a 350 is 4.00,that is one difference..the balancer on the two is different for one.the 305 has a fat balancer,the 350 has one that is slightly skinnier..the 290 combo i said to go with will pull with anything off the corner and you will have to gear it to pull down the straitaways..with 2400lbs and a small 3/8 track i say my combo will be hard to beat.it screams,is bullet proof,rockets off the corner,all you gotta do is gear it so it doesnt run out on down the straitaway..i say try it and let us know what the outcome is,i already know..good luck!

[This message has been edited by jpotter94 (edited April 26, 2005).]

5tbone
Dirt Full Roller

Total posts: 58
posted April 27, 2005 05:58 AM  
jpotter did you get my PM

jpotter94
Dirt Forum Racer

Total posts: 94
posted April 27, 2005 09:33 AM  
every sharp or jagged edge on the inside or outside of the block needs ground,it is cheap insurance that the block wont crack.as far as grinding the lifter valley,grind it all smooth in their so the oil returns to the bottom easier,you want the oil in the bottom not hanging around in the lifter valley,ect..the motor will be enough for a 2400lb car,like i say you will just have to gear it to pull down the straitaway due to the smaller cubic inch,but it will jerk the doors off anything coming off the corner.if your hole class has to run these rules trust me there will be nobody outmotoring you at all..you can hook this motor up relatively easy with leafspring cars.leafspring cars are very fast with smaller cubic inch motors,you dont want a big motor on a leaf car,it is overkill.like i say if your relatively close i would be willing to build it for you and your price range,you have anymore questions feel free to ask..

sbc350
Dirt Full Roller

Total posts: 59
posted April 27, 2005 09:06 PM  
quote:
Originally posted by jpotter94:
you cannot go by the serial numbers to tell the difference between the two because they make a 3970010 350 and a 3970010 305.

I'd like to see some proof of this one. Casting numbers will tell the truth about the block.


19J
Dirt Freak

Total posts: 370
posted April 27, 2005 09:32 PM  
3970010 302ci 1969 4 bolt
3970010 327ci 1969 2 bolt
3970010 350ci 69-80 2 or 4 bolt

No such thing as a 305 with those casting numbers according to mortec.com.

sbc350
Dirt Full Roller

Total posts: 59
posted April 27, 2005 09:48 PM  
Exactly, all three of the engines listed have a 4.00" bore. 3970010 blocks did not come with a 3.75" bore.

jpotter94
Dirt Forum Racer

Total posts: 94
posted April 27, 2005 10:52 PM  
you are right i had it backwards.even still i never use casting numbers as a rule,there are two many veriations with one number PERIOD!to prove it just because you have a 010 block doesnt mean you have a 350,and vise versa with the other three 010 block variations.thus the reason why i said dont always go by casting numbers..best way is by the bore.stroke is always a good way to tell too but the 305 and 350 are the same stroke..

350sbc do you wanna argue the fact that a 305 has different bore,balancer and are balanced different as i said??

[This message has been edited by jpotter94 (edited April 27, 2005).]

sbc350
Dirt Full Roller

Total posts: 59
posted April 28, 2005 10:12 PM  
Nope, nope, and nope. The rest sounds good. It just seemed you were confident in your response about the 010 block. No hard feelings, carry on...

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