Stroked 265 SBC characteristics, opinions?

Thanks Bruce

Interesting comments about Mr Vizard, I've got some of his books but haven't seen that one.

For some reason that sleeved 462 also rings a bell (maybe read on here?), now that's extreme machine work!!!

 

Now, just ***uming it CAN actually be all bolted together, what do you reckon my original plan would produce?

Would it be a reasonably torquey motor limited to 6,000 6,500 rpm depending on cam selction? Or with a with a Duntov stick?
Do you reckon I could acheive 350 - 375 hp and similar level of torque?

 

Back in the late 50's they used stroker cranks to build 352 cube 283's. Don't know if any of that is still available or not. I'd be inclined to stay at 288" or 292", use the Duntov and early dual quads, and bolt it to a T56 6-speed (with a Chrome Hurst handle and a 4-speed knob) and then back to 4.88 gears. Trust me, that'll be fun.

 

I believe the 352 was off a 4" bore and a 3.5 stroke so basicly a 350 just a .02 longer stroke

 

Yeah you can still get 3.500" stroke cranks but they are at least $100 more than the cheaper 3.750" cranks and that has steered my choice so far. I don't know what pistons and rods (custom?) were originally used with the 352 motors but I reckon I'm stuck with 305 pistons due to the required deck height and the unlikelyhood of reaching a 4" bore. Rod wise it's 5.565 for 3.750" throw or 5.700" with 3.500" throw, both with 305 pistons and deck clearances of 0.025 & 0.015 respectively.

I suppose a turned down 3.480" crank would be even cheaper again but feels like it's diluting my goals.

 

Another possibility to confuse the issues: Chevy rod journals come in two sizes. You have and will likely use the smaller to get more clearsnce--raising the possibility of offset grinding throws on a cheaper crank for more throw.
Always glad to help out by pouring gasoline on a confused and overheated process!
Studying clearance: A possible thought might be to ***emble stock crank and cam into block as is, then add a stock rod with shims, perhaps oiled cardboard, under cap to move it out and approximate clearance issues of a stroker and detect limit areas...some clearance issues with actual rod could also be studied less directly by observing where closest approaches are and guesstimating. I think all of this will be easier to visualize with actual iron.

 

I've ground a ton (probably more) 350 cranks to 3.5 stroke and small journal rod size. I don't think you'll swing a 3.750 stroke without using small journal rods - which takes you back to using 5.700 rods. My (somewhat educated) guess is that a 3.500 stroke motor with 5.700 rods will make a better combo than a 3.75 with 5.565 rods.

 

If my math is right, your original combination gives you 339.5 cu.in. with lots of clearance questions and short rods. If you bore to 283 std. size, (and maybe you can go o/s depending on your block) and use a 3.500 stroke you'll be at 330 cu.in. with stock type pistons and stock 5.700 rods, a better and easier combination. Not saying the 3.750 stroke can't be done, (and I still think I may have done a couple) I've just never been a fan of the 400 rods. I've also ground a lot of Chevys to use a 6 inch Olds rod, was a real common dirt track setup in the northeast in the '90s. Long rods are just better. I'll expect incoming.

 

Just found one early datum point leading to another:
July 1955 HRM, surely one of the very first thrashes on the new V8, simple exploratory hopping adds 83 horses to a new 265. Last paragraph promises a followup including boring and stroking--don't have that citation yet.
Big improvements in heads happened in 1957 and about 1963...I can remember HRM saying later that stock '57 heads were better than heavily worked '55's.

 

One other consideration. At least some off the shelf 383 stroker cranks require 5.700 rods. 5.565 400 rods will cause the counterweights and pistons to collide. Not a problem with a reworked OEM crank. This is firsthand knowledge, not hearsay.

 

Good ideas on the clearancing Bruce and yeah I've been looking for a combination where and if I could use the 2.000" jounal rods but I haven't worked it out just yet

Agree with all your calculations and a 5.700" rod and 3.500" stroke would be a nicer motor. The problem it throws up is that I'd need a pistom height of 1.575", which is the 400 small block piston height, but the bore is much too big and don't want it to be a custom piston job if avoidable.

What pistons were you thinking of as I can only find 3.875" 283 pistons with a height of between 1.780" & 1.805"?

The closest piston I can find which is close ish is the 307 3.875" with a height of 1.640". When used with a 3/500" stroke and the 5.700" rod it's located 0.065" above deck height which sounds a bit high to me.

What do you giuys reckon?

Steve

 

I think this will get you close...

Rods - from a Rover V8 (299 incl VAT on debit master card)
http://www.v8tuner.co.uk/product.php?id=334

KB153 Pistons (USD 288.39 on debit master card)
http://kb-silvolite.com/performance.php?action=details&P_id=2
http://store.summitracing.com/partd...part=UEM%2DKB153-8&N=700+115&autoview=sku

Fifteen minutes spent on google.co.uk to put a 3.75" crank in your 265... priceless

Seriously, offset grind that crank some more, or get a 3.85" arm (or big deck cut) and you'd be going to town.

-bill

 

Nicely written Bill, made me laugh!!

My original combination was closer but you did lead me to another KB 305 piston (kb186) with a height of 1.443" that would allow me to use the 5.7" rods which would end up only 0.007" down the hole. Compression would be a little lower than i'm aiming for but worth looking at again.

Those 5.85" rods are interesting though and warrant further thought, how'd you stumble across them? I'm still keen so see if any pistons out there would allow the 3.5" stroke, 3.875" bore and 5.7" rod.

Anyone know of any 307 flat top pistons about?

Steve

 

I had a look at the Don Francesco book "How to modify Chev V8 engines" over the weekend.

It was originally printed in '57, with an update added just after the 327 came out.

In the original section regarding stroker cranks, it says that you will need to notch the bottom of the bores for rod clearance depending on the stroke. I am ***uming that these would be welded strokers based on 3" stroke cranks.

In the updated '62 section, it says that you can't drop a '327 crank into an early block (without the radius at the bottom of the bore) because the counterweights will hit. It says you could machine the counterweights and re-balance the crank, but doubts that you could grind the radius on the bottom of the bore without hitting water.

 

Been doing more research and found that speed-o-motive actually do a kit for the 265 using a 3.750" crank, 5.565" rods and undisclosed pistons that you have to asume are the 305 items.

I've also found some KB 305 stoker pistons that allow the use of 5.7" rods (1.433" height) and even a 6" rod (1.130" height).

So it's looking like a 344 with a rod/stroke ratio back up just short of a 530's at 1.60

 

Thanks for that Simon, might have to call Speed o motive and see if they are modifying the counter weights

 

So, did you ever see my old sign-out line - the one about how smoking pot ruins your long term memory, or your short term memory - now which one was it? Unfortunately, I don't smoke pot; so I'm looking for a more flattering excuse than senility.

Anyway, hell if I know where I came up with the 5.85 figure, but it was stuck in the back of my tiny mind somewhere; thought it was a circle track thing.

Another thing I don't know why: why firefox's site has a link to add the google.co.uk search engine, but not the google.com on my search bar. Damn if I know. But to cut a short story long, I just ran a search for "5.85 connecting rod" or some **** like that on google.co.uk. Maybe they don't know I'm a Yankee...

Best of luck, and keep posting as you go. It may not be the most practical (as far as HP/money ratio) setup, but WTF, we're just bench racing for now. And the only way anything new gets done is if something new gets tried.

-bill

 

A coupla more books:
McGurk on the Chevy V8 gives max bore/stroke recs for 265, calls for stroked 327 with cut weights, again about 1962 ed of earlier book.
Grumpy Jenkins early book, the one focusing on regular scrounged Chevy parts rather than special castings, has a bit on this and lots of very good Chevy stuff of all sorts
Sort through '55-9 type HRM, find the one detailing 327 crank in early block.
Aren't there funny length rods in one of the small SBC's??? I'm nort sure if I'm remembering the wretched 262/267 things or the later LT 1 type 265??

 

Certainly seems like you've got a cool book collection there Bruce!

Any chance of some specific ***les of some of the early books so I can try and find copies please? I've got no access to early HRM so will have a better chance in tracking down the books if you know what I mean.

I've found one Grumpy book but sounds a bit late maybe, it's called The Chevrolet Racing Engine By Bill Jenkins & Larry Schrieb from about 1976, is this the one your talking about?

I'm quite sure there isn't any Chevy V8 rods shorter than the 400 5.565" but will stand corrected id someone knows different.

Thanks again for your input Bruce

Steve

 

interesting read. What has transpired with this project?

 

It's still on going, I've been doing more research when time allows as I've got to finish off the downstairs of my house before I'm allowed to extend the garage and then i'll get into building it. It will be early next year if all goes well.

Anyway I can update you a little though as I've learnt more as some of new books have turned up since my last post.

As Bruce and few of the others had mentioned, the 327 block had been clearanced / modified in 2 areas to allow the 327's new 3.250" stroke crank to swing around in there. In addition to a 1/4" of stroke, the cranks counterweights were changed in their shape and this added 1/4" in length to the counterweights and an overall diameter increase of 1/2" and this is the reason that a stock 327 (or bigger) crank won't fit into a stock 265 block, well one reason anyway.

I lifted these pictures from "Musclecar & HI-PO Engines Chevy 302 and 327 by Hot Rod Magazine" to show you
[SIZE=+0]
[/SIZE]Here's a photo of the 265 block with 2 areas highlighted, I believe, but will stand corrected, that 283's are the same but some later blocks were done on the 327 tooling and came clearanced.



This photo of the 327 block shows were the bottoms of the cylinder bores were clearanced.



This photo shows the 2nd modification where the main webbing also received machining for clearance




The best combination at the moment appears to be a Speed-o-motive's 3.750" crank, stroker clearanced 6.000" rods and United Engine & Machine Co's stepped dish piston 305 stroker (334ci) piston KB835 that has a height of 1.133". Put into a standard deck block it sits 0.017" in the hole. The 6.000" rod also brings the rod/stroke ratio back up to 1.6 which is only 0.03 lower than a standard 350 so much better than the Speed-o-motive kit using the 400's 5.565" rod and stock height 305 piston with a 1.48 ratio. This equates to opening up the stock 3.750" bore to 3.776" to take a +0.040" 305 piston which will open it up to 336ci short block with a 1.60 rod/stoke ratio. I'm still waiting on United Engine to come back to me on the piston configuration to ensure it is useable for desired compression ratio.

I have also e-mailed speed-o-motive to find out more about their crank to see it it's only the bottoms of the bores and the pan rails that need clearancing with their crank. You'd ***ume that they have taken care of the counterweight to main webbing clearance issue but hopefully they'll come back to me and answer this point. Also asked if they'll supply the crank by itself and if they reckon my combination of rods and pistons will work but I have yet to receive a response from them. If anyone lives in LA and fancies calling them to clear up the counterweight to main webbing clearance issue then their number is 626-869-0270 and I'd really appreciate it otherwise I'll get round to call the States eventually once the wife's asleep one night.

My initial cylinder head thoughts are a pair of 58 vette heads (casting 3755550) that my mate has, these are 60cc and have 1.72 & 1.50 valves. I'll investigate fitting larger intake valves, 1.940" valves would help. Would probably install hardened seat for the exhaust valves also. I also still need to establish whether the stepped dish piston design is compatible with the combustion chambers of these heads.

I'll update you when I have more info.

Steve

 

A very late up date on some missing info.

The Speedomotive kit described appeared to be pulled a little while after emailing them with the block pics. I've still yet to do it and the only I reckon you'll get a 3.250" crank in there is to get a used nascar/cup crank that has been highly profiled and it might fit. But then have to deal with BBC snouts and honda 1.888" jounal rods