old tired rebel

Can anyone tell me what it will take to build a stroker motor out of a 307

cutlassefi

I don't mean to be a smartass but I have to ask....Why?

old tired rebel

Well for one it's all I have and 2 I was taught to use what you have.

442_Mustang

Because there's a pretty tasty one in the newest Engine Masters magazine. They used a 330 crank and it actually did pretty well.

442_Mustang

By the way, I guess the answer to the question is to find that magazine. Mine's at my buddys house.

old tired rebel

I have never seen that magazine in the local book store where I shop.

old tired rebel

Do you have a link? All the ones I tried didn't work.

t bell

I've got an writeup in PHR and I think it made about 450hp. On stock heads no less. I'll find it and scan it. It's pretty recent.

old tired rebel

Thank you. Can I send you my email?

t bell

Sure thing.

old tired rebel

Ok I'm not in a hurry. I don't get the ccar until next month.

captjim

http://72.22.90.30/phpBB2/viewtopic.php?t=62659

The only reason to build a windowed 307 over a solid 350 is to comply with some rule, such as SS racing or the EMC here.

Also, I wish guys would quit calling those heads "stock". There is nothing stock about them other than valve location. Those "stock" heads would probably cost you $4,000 to get duplicated.

380 Racer

I couldn't agree more!!!

t bell

Alright, alright. Get your panties out of a wad. I was run in saying stock heads. I should have said heavily worked iron heads.

cutlassefi

Very heavily worked. I wish him luck in trying to duplicate that build without causing a greater national debt.

captjim

My panties aren't in a wad, I am correcting false information that you gave. I have yet to meet one guy who put a bunch of $ into a 307 and was happy with it. Posts like yours make it sound like getting 425 HP out of a 307 is easy. Dale is a member here, there have been several threads about his engine, do a search. He is gmrocket. IMO, that engine would cost $10,000 + to replicate. For way less you could build a 350/403/455 and get more performance.

t bell

There are more things in life to get upset about. I came back and acknowledged that you were right, I shouldn't have said stock heads. You called me on my mistake, I agreed with you. Didn't mean to offend you with my panties statement.

jslabotsky

OK, I think we all just want to help the original poster.

rebel, I think the important thing to take away from this is that you could probably buy a running, used 350 or 403, give it the once-over and get better results for less money than it would take to get the same result from a 307. Plus, assuming the 307 runs, you can drive the car while you're working on your new motor.

old tired rebel

Thanks to everyone for their input. But I sure didn't mean to start a small war here.

captjim

There is no war at all, just a discussion, that's all. You can build a stroker 307 if you like, it would be cool, but the same $ put into a 350 will get you more performance. I have just seen so many fellas be disappointed with the results of 307 builds on the street that I have to see $ and time wasted.

t bell

Yeah, no war. You asked about info. You never mentioned cost. Which I gave. Jim clarified that it would not be cheap. Which I agreed. And I think jslabotsky made a good point in being able to drive the car while you work on the new motor.

joe_padavano

The easiest and least expensive way to build a "stroker" 307 is to throw it away and install a 455.

First, unlike SBCs, all Olds small blocks use exactly the same 3.385" stroke. That means that any "stroker" will require a custom crank, custom rods, and custom pistons. A 455 pretty much bolts in and brings a 4.25" stroke. No, you cannot use a BBO crank in a 307 without MAJOR machine work.

Bottom line is that you will spend thousands of dollars just getting the custom reciprocating assembly, or you can spend less on a good-running 455 (or 350, or 403).

easytobedead

well if i hit 307hp out of the 307,then you will finally meet 1 person

geckonz08

Yes , as the others said and after I read the article ,(interesting as it may be ) the $ would be much better spent on a 350, 403, 425, 455 And, to get the power of that 307 from the larger engines you would still end up with change.
BTW I know jack all about engines really but am rapidly learning the costs associated .

mike

captjim

Even using Honda journals, you can only get a 3.610 stroke. Is that enough of a gain ( .125") to justify the cost? Not IMO.

I have always said that the 455 was a "factory stroker" They took an under square engine (stroke shorter than bore, 4.125" bore and 3.995" stroke) 425 added a full quarter inch of stroke to get 4.125" x 4.250" = 455 cubic inches. The result was an engine that makes a ton of torque at low rpms, which was required to move those behemoths back in the late 60s and early 70s.

old tired rebel

I guess I will look around for a BBO to go in after I pick up my wagon.

380 Racer

I currently run a stroked DX block in my car producing over 700 HP and 580 TQ. It is a VERY high dollar build at 425 cubes. My last motor had an offset ground 330 crank with a 3.50 stroke and 4.155 bore which made it 380 cubes and produced 560 HP. That only cost around $8000. Nothing is cheap!!

joe_padavano

And of course, a DX block is VERY different from a 307 block...

83hurstguy

I don't think I have a ton of money in mine, but I'm pretty happy with it. The only reason it's limited on power is due to the tiny cam (didn't want to push the CCC system). The heads are definitely flowing enough to make power up to 6k. This thing would be a fun street engine with a CCC delete and more cam. It would probably push the low 300 hp range that way.

So you can bump your number to 1. It at least makes a VIN 9 G-body somewhat fun to drive.

Anyways, don't waste your money on a stroker... if you are dead set on building one, your biggest enemy is the compression. You gotta wack some stuff to get that up if you are gonna use dished pistons (and replacements are shorter). Milling gets expensive and drives the cost way up. You gotta at least do a good valve job and some bowl work, once again not that cheap. You can do a regular 350 and save yourself quite a bit of $$$. Even better, a BBO.

captjim

I was hoping you would chime in, Luke. That was a well thought out combination of parts. Here are a few details for those who aren't over at OP,
http://www.oldspower.com/vb/showthread.php?t=49664
http://www.oldspower.com/vb/showthread.php?t=47853

It ran 14.4x, right? Could not find the ET. Great number for a 307 on the computer!!

But, I gotta ask, what do you think the same $, head work, compression, and a custom cam would do in a 355? My 9 to 1 355 ran 13.9, weighed 300-400 lbs more, had less gear and inferior headers.

83hurstguy

It was 14.50, really minimal tuning (set timing and go). It's got more in it now due to a carb rebuild and some upgrades... (probably a .2x?), but won't be able to find out until spring. The MPH is low due to the converter. Have a handful of tricks I was going to try last time to the track (and measure converter slippage at the finish), and the ignition module took a dump on me. Thanks for posting the links, for some reason my timeslip pic had disappeared, I fixed it now in the first thread. I also need to weigh my car. It's a heavy beast, A/C, full power everything, radio, extra bracing, etc...

84HO425 on ROP has gone 14.50 with his, on the computer, no EGR, AIR delete, hedman headers, 8ish:1 compression (replacement pistons, no milling I believe), no bowl porting, but he has the Engle 210/216 in it (advanced so cranking compression was at 175-180). He's real happy with it. Mine should show more potential than his due to the CR and heads, but my cam is smaller. (I guess that's number 2 on your list of 'happy 307 owners', haha).

If you did the same combo on the 355, upped the cam slightly to compensate for displacement, kept the CR the same, I'd expect at least a 13.50 out of it, if not a bit faster. The torque from the increased cubes would really help. When you have a "shift at 5k" combo, displacement is only going to help. This thing would probably fly with a "shift at 6k" cam, but I don't like doing that with my numbers matching engine containing stock rod bolts with 102k miles on them. It actually saw 5900 twice last weekend out fooling around on the street when the tires went up in smoke. I am pretty sure the heads are not holding it back.

I'm keeping it in the car next year, I want a 13.99. I think it's got it in there.

and in terms of cost, it's basically a $1k set of heads with me doing the porting (assume that cost includes the carbides/rolls)... custom cam with lifters and springs was a bit over $400. The rockers weren't necessary with this cam but I had them... had another $1k in machine shop bills between milling, balancing, checking, and fixing some screw-ups. Ok, nevermind... I have a lot of money in this thing, lol...

70 cutlass s

There must be a big black hole somewhere, because everybody upgrades to a 455. So if you can find this hole throw your 307 in the pile, pull out a 350 or something bigger and just run.

380 Racer

This reminds me of way back when a few guys would build 283s instead of 327/350s. In order to make any HP they had to wing the crap out of them. Looking at a 307 scares the hell out of me......there isn't much keeping the crank in there.
Luke, I wish you luck but there will be a point where your efforts produce less of a return. Plus the last couple weeks had some excellent adjusted altitude. Again good luck.

83hurstguy

oh, I know... there is a reason I have a completed 433 ready to go in

307 doesn't scare me... it has thick cylinder walls, the pistons aren't that heavy, it's not turning that much rpm, etc... now a 403 with the huge slugs... I was even surprise how low of a turning torque my rotating assembly required with cast rings.

70 cutlass s

Yeah I had a friend that built a 283 had a lot of money in it. The engine sounded good. When he told me he wanted to race I told him ok. I had a stock 350 at the time it had headers, a mild cam, Q-Jet, and 2.7? gears. He was so mad when I bet him by 2 car lengths. I really didn't have any money in mine I even told mine didn't have any power witch it didn't. So my advice is you want to make power go bigger.

joe_padavano

The only substitute for cubic inches is rectangular dollars.