307 small chev

Date 11-03-2006 03:05

Hey SD,
I talked to my brother who builds Chevy racing motors. He said the old 307's were like the 'ol 327's and could really crank if set up with the right components. He said he did a couple that dyno'd at 380HP and could easily go to 400HP. He said it was really how much you wanted to invest for the HP you wanted. If you want some info., let me know and I'll get him to send you some specs & prices.......Denny

By Sourdough (****)

Date 11-03-2006 15:11

Denny, that would be great. I've got the block sitting in the garage. It runs, but burned oil. Instead of a re-ring, I really would like to add some muscle and put it back in my '69 for a #s matching truck. My Camaro has a 327 in it and it screams. I imagine with the short stroke the 307 would be real close.

By dmilesdot (**)

Date 11-10-2006 17:07

Some of the 307,s were not boreable because the cylinder walls are very thin. Before you have someone bore the block have the wall thicknesses checked. It may sound like added expense but if you wind up with a really thin cylinder wall its gonna overheat.

By jwright650 (*****)

Date 11-10-2006 17:32

If the block has had any core shift, overboring could make it very thin or even go to water when the walls are thin to begin with.

By Sourdough (****)

Date 11-11-2006 18:09

It came out of a 69 c-30, (1 ton). How do you check the cylinder wall thickness? - Sourdough in Pueblo

By CGP_Marv Date 11-22-2006 02:15

hey yorkiepap, can u send me that info tooo?
i have a 307 from a Buick le saber and was looking into puting it into a sport compact car and racing it, send any info u can to mn69ers@aol.com

By yorkiepap (***)

Date 11-22-2006 18:52

Hey Marv,
Since I'm off for 4 days thru the weekend, I'll get together with my brother and get him to give me a printout of HP listed and components needed. I think I can get him to send it to you directly since the program he uses is on a database on his computer. I'll let you know.....Denny

By Sourdough (****)

Date 11-30-2006 17:10

Yorkiepap: What's happenin', man?

By yorkiepap (***)

Date 11-30-2006 18:57

Hey SD,
I got my bro' to print out all the info.. There are about 30 sheets of info and each segment will have the changes highlighted so you can see what components will change the HP rating. There's another fellow here that also wants the info.. As soon as I get them, I'll make a duplicate set and let you know. You'll have to send me your mailing address so I can hard mail the sheets to you. As soon as I get them, I'll get in touch with you....Denny

By CGP_Marv Date 12-08-2006 02:30

i pmed you my Addy thx again for the Info

By Sourdough (****)

Date 12-18-2006 02:23

I talked to my ol man and he isn't impressed at all with the 307's. Said they were Chevy's worst small v-8

By billvanderhoof (****)

Date 12-18-2006 05:05

http://www.mortec.com/borstrok.htm
Here is bore and stroke info for chevvy motors. The 307 motor had the 283 bore and the 327 stroke and was said at the time to be lower polution. The 302 had the 327 bore and the 283 stroke and was marketed as high performance. I don't know how worn out your motor is but valve seals sometimes can have a dramatic effect on oil use and you don't even have to do a major teardown to put them in.
Bill

By Bob Garner (***)

Date 12-29-2006 21:20

I saw a neat device to measure the cylinder wall thickness of an engine block - Dakota Electonics PR-8 sonic tester. It looks kinda like a stethascope attached to an electronic box with a display on it. It's not cheap at $995 US, but a good engine shop should have one of these. See www.dakotaultrasonics.com

My company is interested in one of these for inspecting the thickness of steel sheetpiling, which is only accessible frome one side.

By Sourdough (****)

Date 12-29-2006 21:23

I'll haul it down to a shop and see what it is, thanks for the info!

By CGP_Marv Date 01-15-2007 00:59

any update?

By yorkiepap (***)

Date 01-15-2007 18:48

Hey marv,
I have to apologize for my bro'. He hasn't come thru yet. He's having a mid-life crisis I guess and I haven't talked to him in a while. I'll keep trying....Denny

By DaveBoyer (*****)

Date 01-23-2007 04:24

When I was in highschool ['76] one of the guys built up a 307. It ran pretty good for an amature low buck job. I think they got a bad reputation in the day as they were all smog motors, and the older High Perf motors would easily outperform them. I would think with the right heads, manifolds, cam, carb & ignition timing curve You would be happy with the performance. The longer stroke/bore ratio is fine in a truck motor. I don't see how You would ever get in troubble with a minimal rebore, but there may not be enough material to sleve the bores if there is core shift. And by the way this is from a guy who didn't particularly like Chevy's.

By DaveBoyer (*****)

Date 01-23-2007 04:39

More to the point, You want a set of heads with big valves, even if You have to notch the block a little. On the cam You want lots of lift, but not extreme duration and overlap. In a truck motor You want torque right off idle. There are aftermarket cams for campers and trucks ground with this in mind. Manifolds: Large intake runners matched to the heads with a coarse carbide burr [You don't want the intake smooth inside, turbulence helps mix the air&gas better] and headders or high performance factory cast manifolds for the exhaust, with large pipes and low restriction mufflers. The carb should be about 600-650 CFM. Get the right ignition timing curve, a kit for the factory distributer, or an aftermarket distributer. It won't be a dog.

By Sourdough (****)

Date 01-26-2007 01:03

Got a set of double hump 202's. I decided to go with a 383 again tho. I loved layin smoke on those annoying rice rockets in my '69!!

By DaveBoyer (*****)

Date 01-26-2007 03:12

There is NO replacement for DISPLACEMENT!

By aevald

Date 01-26-2007 03:27

Hey Sourdough, I get the biggest kick out of my kids when they start talking about all of the power etc. in the nissans, mitsubishis, toyotas, etc., you get my drift. I think back to a 65 Olds 442 that I had, a 68 Chevelle Malibu SS that I had, and a torrent of other cars that I had the pleasure of driving or riding in. You could FEEL the horsepower!!! You also can't beat the tones and sounds of those motors, either the high revs of a small block or the deep throaty roar of a big block and the feel of a descently ground cam. I do miss that, I don't miss the tickets that went along with them. Have a good one and enjoy your building process. Regards, Allan

By litchko (*)

Date 04-07-2007 02:23

I built up a 307 (1968 chevelle)mtr. I use to run at the drags(lost track after 52 wins) I bored mine .030 over used, jhans pistons, used chrome seal powered rings,fit my own ring end gaps,crossed hatched the cyl.walls,balanced the rods,pins and pistons.plastic gauged all the rod bearings&main bearings.I ordered the highest horse power hyd.cam(stock chevy)that gm made.I used TRW semi-solid lifters(back off till they clatter than snug them up till they stop).Had the heads milled& the studs pined with a valve competion valve job.Installed a dual point dis.ign.with a high out put coil.Installed a 4bbl.manifold (torker)with a duel feed double pumper holley carb 650 carb with a set of hooker headers(custom tuned).You talk about SMOK'EM up.I had a lot of fun with that rat motor lot of guys would'nt believe it had a 307 in it.I got protested a number of times.I also painted the car my self(it took me 6 weeks painted it vitamin C with lace & some cobwebbing+10 coats of clear laquer)if a fly landed on it he'd slip and break his neck.Maybe this will give you a few ideas sourdough

By Bruce Lindstrom Date 01-26-2008 17:27

Denny, I would you send me the specs and parts lists and price for a 307 longblock, thank you ,Bruce Lindstrom

By BigRob40 (*)

Date 02-01-2008 20:00

why waste you time theres no replacement for displacement. contact powerhouse about a stroker kit! or by a new zz4 crate motor,they make over 430 horse out the box with a factory warranty ,3yrs or 30,000miles.also if their is a problem with it G.M. will service it even if its in a 66box nova! who said doublehump heads,they are way out dated.try a set of heads from Brodix,afr,world ,dart,tfs. you will gain at lest 70hp on the dyno with no other changes.