A roller Block 265 Chevy

First off, if this isn't the correct place for this, I apologize and it can get moved to the proper forum.
Has anyone done this? For the fun of it (and I obtained all the parts for basically free) I am looking to put together an OE Roller cam 265. Utilizing an 88 305 roller block and the rotating ***embly from a 94-96 Caprice L99 (Baby LT1) engine. Since these use a 305 off the shelf modern piston it's cheaper and easier to find than 265 pistons. The cost and weight savings of running an OE roller cam seems like a plus to me for a small cube engine. I probably need my head examined as all of us car nuts do but I thought I would throw this out there and here what everyone has to say.

 

I feel like @Austin kays looked into this a few years ago.

 

What is the rod length

 

Clearify something. Are you saying you wanna put the L99’s rotating ***embly including cam into a 55 or 56 block?

 

The L99 has it's own unique 5.94 rod.

 

No. Put the rotating ***embly in a 305 roller block. And I would pic a different cam than the L99. Something more along the spec's of the LT4 Hot Cam that GMPP made.

 

Gotcha

 

I guess I must have forgotten all I ever knew about solid geometry. If the bore of a 305 is 3.736", the radius is 1.868". 1.868" squared is 3.489424". 3.489424" times pi (3.14159) is 10.96233954416", the area of the top of the cylinder. Multiply that times the stroke of the L99 (3.622") equals 39.70559382894752 cubic inches per cylinder times 8 (number of cylinders) = 317.6447863158016 cubic inches. Where do you get 265 ci?

 

Never knew I the 265 made a return. Since my question I’ve been researching. To tear it down to basics, an L99 is a destroked 305. Therefore all that’s really needed is the crank and rods from a L99 to make any 305 into a 265.

 

This is the bore of the L99, LT based engine not the L99 LS based engine. It also has a 3" stroke. The bore of an L99 is exactly the same as a 305, 3.736. They actually always list the L99 as 265 but it is actually 263. My ***le saying "265" is because it is "close" with the L99 rotating ***embly. And you haven't forgotten a thing about solid geometry, you just didn't plug in the correct numbers.

 

Yes. But technically, with the standard bore it is 263 cubes.

 

Yes math say’s other wise. But Chevy coined as a 265. That’s why.

 

^^^^^ See above

 

Do they make a .020 over piston for 305’s?

 

But also, that Math that was posted was using the stroke of an LS based L99 at 3.622'. The LT1 based L99 has a 3" stroke just like a 265, 283, 301, 302. I have argued with a few guys who have told me a 305 has the same bore as a 265 and I know that is also false. I'm not a Math, Science and Physics expert but I have 30+ year career working in the Engineering field and formulas with the correct info. are your friends. If not it's garbage in, garbage out!

 

I do believe I have seen a few but it isn't common. They make ring packs but that might work for an easy daily driver. I will be putting the gas pedal to this. I will build it correctly.

 

Just looked, they make them. Have fun and keep ******* them off.

 

Fair enough. That's why I said that right of the bat! Thank you Sir!

 

First, I applaud your creativity. Is there any goal here other than just being able to say you have a 265/263 cu in engine ? Personally I have always thought it was wrong to give up displacement when building a streetable engine where torque is your best friend.

You did a nice job coming up with an "outside the box" way of doing it, but I think there are other considerations that you aren't thinking about. First is the choice of a cam. I think the specs for the LT4 Hot Cam are not well suited for only 265 cu in. Its designed also to use with 1.6 rockers. Between the cost of the cam and the rockers and springs.... I don't think they will be budget friendly. Then there is the consideration of whether the valves will clear the pistons .....I don't know. I do know that I purchased some new/unused forged "smallblock" stroker pistons for about 1/2 price to see if they will work in an LS stroker. They seem usable but I will have to moch one up to see if the difference in valve angles will require me to machine the valve reliefs. Yours is not quite the same problem as mine, but still needs to be verified. I think a cam producing a wide power band with lots of torque would work better given the small displacement and just use some oem rockers and springs.

Personally I'd rather build the largest combo I can build for the same/similar cost and enjoy it.....but I do like to see people "think outside the box" ............

• Chevrolet Performance LT4 Hot Cam Hydraulic Roller Camshafts
  
  Camshaft, Hydraulic Roller Tappet, Duration at .050 in. 218/228, Lift .525/.525 w/1.6 ratio, .492/.492 w/1.5, Chevy, 5.7L, LT1
  $593.43 @ Summit

 

The idea is mostly for the fun of doing it because virtually all the parts are free. I have one from each year in my garage: 55, 56 and 57 and they are all unique to themselves. No, 57 265's are not left over from 56. While I'm sure that happened, a 57 265 is it's own engine, different than a 55 and 56. As much as I am a Nostalgia guy (hence liking the 265, I've become somewhat of 265 historical nerd!) everyone is stuck way in the past on building one. Nobody has made an attempt to build one with modern parts instead the old Duntov cam and heads with peanut sized runners..
I'm currently in the process (procrastinated for years) in building a 56 265, 10.5:1, L98 heads, ZZ4 intake and using a Qjet tuned correctly for the setup. The trick here is run a flat or spend big bucks on a retro fit roller.
Not knocking that but I think there is a lot more potential than most think. I see so many say they are junk and that's why they made the 283. You can make the same build as a 283, just 7% less because that's the difference in their cubic inches. Yes, 55-56 265's have the issue of the "pulse oiling" system. Not the best idea but easily modified. A 57 265 shares the same block as 57 283 with "full oiling" like every other small block.
As far as the Hot Cam goes, I will most likely be running 1.5 rockers. so the .492 lift, 218/228 duration @ .050 and 112 LSA should make for a fun running engine. Although I didn't say it before, my choice for a head is L98 Aluminum heads. On an L98 350 the Hot Cam kit was a direct bolt on even with 1.6 rockers. I would still check valve to piston clearance but it should be no issue. These heads have all the flow a 265 needs for a street strip application. I am also running LS6 springs which will allow me more lift if I wanted with any head modification and it will be a more stable valve train at higher RPM. I am not looking for the fastest thing on the planet. I like the high winding sound and my car will be just streetable enough to drive anywhere and run down the track every chance I get. If I really want the bang for the buck and make something faster, I like you are doing would build an LS based engine.
Since you like out of the box thinking, Something was going to eventually run on the 56 265 will now probably get run on this engine instead. I have a complete turbo setup from an 80-81 Turbo Trans Am. The idea here is a higher compression/lower boost build to be easier on parts. If you haven't seen what that setup looks like, do a search for it and check it out.
Truly in the end, I just need my head examined but it all sounds like fun to me!

 

Thanks for not beating up on me. I know there are a lot more Chevrolovers out there than us Blue Oval guys, and to tell the truth, I never paid much attention to orange motors past '62.; Maybe I should have. After re-doing my math, I think you're going to have to get a bigger tach. That thing ought to be a screamer.

 

Are you Looking for 7,500 plus ?
Good Light parts to live @ High Rpm's
Many Z 302 bent & broken push rod , studs , rockers because of weight .

 

No problem. I knew exactly what you did once I saw the stroke number. 265's are their own unique animal anyway. All 3 original years 55, 56 and 57 are all different design/configurations. I happen to have one each but this "mad scientist" idea popped in my head while doing some research on 265's.

 

I am looking at not exceeding 7K. My plan is to run L98 aluminum chevy heads, roller rockers, guide plates with hardened push rods and LS6 springs. The springs do 2 things: free up space lift without machining the heads and they are more stable for higher RPM.

 

@bfalfa55 Did not know Rpm's
Most that do small cid what 7k plus
Just good light HD parts to live,
Been long time since I see 265
I know / sure I seen block Valve relieved for big intake valve ,
How about if going big valve oring block & use copper gasket notched for vale , when coms valve notch on piston
I brazed carbide to a valve to notch piston with head @ mock up ,
Again Not for sure if able to do , just a thought .
Also seeing want to use 305 block so notched block for valve not required I do not think so?

 

With a reasonably sized roller cam I should be able to have it run well under 7K. A 1.94 intake clears a 3.81" bore in my 56 block with no problem. I will have to see how well it clears in the 305 block with a standard bore. I may require boring but I will lay that out. Something else I don't see anybody talking about these days is offset head guide pins. I think that is an old trick nobody uses these days.

 

Rebuild 305, install earlier heads with perimeter valve cover bolts, slap a 265 sticker on each valve cover or the air breather and ... lie your face off

 

Ha! That would work too but I did get only a 305 roller block, no rotating ***embly. I got all the parts so close to free that even if I s**** the idea, I will make money s****ping this stuff!

 

I used dented up 283 covers with shaft rockers heads ground down bolts holes removed with some JB to add 283 markings , 427 sb