Technical A 265 Chevy build with a cool story

801 on left, 416 on right

 

Some guys will use an old CD (preferably RAP CRAP), vaseline to seal it to the head, and use alcohol in the syringe to make a cheap and easy device to CC chambers. Post your results. Butch/56sedandelivery.

 

I haven't read the whole thread, but I did see the question about the road draft tube reuse, etc. If this has already been mentioned, I apologize, but Danchuk (maybe others) offers a kit to replace the road draft tube with a PCV valve. This is desirable to some so you don't have to smell engine oil vapors or have the oil mist collect on things in your engine compartment...

http://www.danchuk.com/ItemForm.aspx?item=13282

 

My plan was to leave it but block it off at the end of the tube and in the block so it was there for looks but run a PCV setup. Depending on what fuel induction setup I run, I may have to get creative with the PCV setup.

 

Well I did a crude cc job on both of the sets of 305 heads. I used a clear CD spacer and I used CARMEX because I couldn't find any Vaseline. I used water and it worked ok. The 416 heads are definitely 58cc's. My 801's make actually be 601's, the casting numbers are really hard to read even cleaned off with a wire brush. It is safe to say they are very close to 53cc's ! This makes me happy as I won't have to do much else but clean these heads back up and paint them whether I have them milled or not because they really look to be in great shape. With my flat top, 4 valve relief pistons and the smaller chamber heads, how much head milling and block decking do you think will be needed with a thin steel shim gasket to achieve 9.5 to 1 ? Hey Butch (56SedanDelivery), I know you stated on the last page as to possible ratios to achieve but where would the milling be performed to achieve the best scenario at 9.5 ? You have added a great bit of info. for the best gaskets and everything else, SO enlighten us again with recommendations !

 

You can deck the block to "0", or 9.00, that's .025 off the surface (9.025 is stock deck height), BUT be sure and check how far your pistons are "in the hole" before you do this. Don't make the same mistake I just made. My "regular" machinist was on vacation, so when I needed my block tanked and decked, new soft plugs and cam bearings, I used a friend of my machinist, who has a different shop. Now, the deck surfaces are too rough for a steel shim head gasket, @#$%^&*()! And, I don't want to use a MLS or composition gasket, so, it looks like MY machinist is going to "fix" it for me, but it'll still cost me full price, plus he has to tank the block afterwards due to shavings from decking again, and that means new cam bearings, AGAIN. Be sure and check your quench after finding everything out BEFORE any block work, somewhere around .040, +/_ a couple thou. And check the valve to piston clearance also. I would't get too carried away on milling the heads, since they are ALL thin castings now; angle milling them will probably get the most material off where it really needs to be taken from also. I don't think you'll get 9:1 with everything planned however. Your 265 only had 8:1 to begin with! If you had 2 valve relief pistons, and did all the other things, milling, decking, thin gasket, then maybe 9.5. Like I keep saying, it's really hard to build any kind of C.R. with these small CID, short stroke engines, unless you go with specially made pistons ($$$). You said you were planning to supercharge it at some point in time also, so don't go over 9:1. Butch/56sedandelivery.

 

I would be interested in a set or 2 of the 305 steel shim gaskets if you have extras and if you have no extras you want to part with, what are some part numbers for the so I can drum them up. I think there is a few sets for sale by a guy on Ebay right now. I am waiting for him to answer me back. Also, I used this compression ratio calculator, https://www.rbracing-rsr.com/compstaticcalc.html. Is there something you know this calculator doesn't take into account ? When I put in 3.79 bore, 3 in stroke, .025 deck, 53cc chamber and a .020 shim gasket with 5cc's for valve reliefs. I get 9.36 for a comp. ratio.

 

You also have to consider how far down in the hole the pistons are, as most rebuilder type of pistons usually have about .020 off the top of the piston to compensate for decking/overbore, in order to maintain the stock C.R. BUT, many times, no deck machining has been done, or the block was't bored, just new pistons used; then they're just down the .020, and you LOSE C.R. Be sure to look at the 305 "BOAT" head gaskets, many times they will still be steel shim, especially if they're NOS. My stuff is't for sale at the moment, just too hard to come by, especially with the Stock/Super Stock racers also wanting them. IF I use a composition head gasket, I'll let you know if they're available. The last 4, 305 steel shim head gaskets I bought, were part of a "bulk" buy from a boat dealer, and there are no part numbers embossed on them (they're not in a package). Mr. Gasket sells a #5780G composition gasket with a .028 compressed thickness, and that's the pair I have that I may wind up using if I don't have the block re-machined. I'm sort of leaning that way, this little motor is just getting too costly to throw even more money at it. And with the quality of gas available (cept' for race gas).............Butch/56sedandelivery.

 

I will have to mic my pistons and see. They are old GM factory .040 so my guess was that they weren't like the more modern rebuilder types. The measuring will tell for sure when I compare them to the original standard bore pistons.

 

I saw the Bay ad also, and sent the guy a question about IF they were for less than 4 inch bores. Never heard back, so I took a chance and bought a pair, there's only a single left now. If he had answered, I probably would have bought 2 pairs. Did you happen to buy a pair? I have several pairs of the "wrong" steel shim head gaskets already, I don't need any more! Butch/56sedandelivery.

 

Just picked up a std bore 55 265 almost complete for free ,,found the missing parts ,,,exhaust manifolds ,generator and bracket and carby etc. for $125,,,,,a free Mallory twin point I will convert to electronic ,,it has a very very small lip on the bore ,,would like to clean up the bores and just rering it ,and new bearings etc. Its not going to do a lot of miles in the car it will go in ,,,I will drill the rear cam bearing journal ,,great thread by the way ,,,what's the difference with the oil pan gasket ?,,,

 

Because the 55, 265 does't have an integrated, block mounted oil filter, the shape of the pan is different in that area. That area does have the road draft tube exit through it, which is also different than 56 on 265, 283, 327 engines; we won't worry about the rest of the SBC's, because they're not "traditional" anyway.

 

No Butch, I didn't buy any because he didn't respond to me either. I will find some , I'm sure if i just take my time and keep searching. I f I run across multiples, I will let you know.

 

Just cc'd the valve reliefs and they are 1 cc per relief. If my .040 pistons are .020 shorter, would that make the compression height 1.77 instead of 1.79 ? If that is what the modern rebuilder pistons are, then I think I am good as these measure right at 1.79 like the originals. Have another question too. These pistons have a silvery colored coating that is kinda flaking off and inconsistent. How should I remove it ? Would lightly bead blasting these pistons hurt them in any way ?

 

The compression height/pin height on 265/283 engines is 1.82 so you're already .050 in the hole. Your quench is already out of limits, unless you have the block decked. I'd try some lacquer thinner on the flaking pistons, don't bead blast them; if you have to however, soda blast them.

 

I stand corrected Butch. I measured again more accurately then a rough check with the calipers an I came up with 1.8125 on my .040 pistons. Since they still have the wrist pins that came with in them, I may have a slight margin of error, so I will have assume they are very close to the 1.82 since I measured 1.8125. It is safe to assume then that these factory pistons are on the factory compression height so I am not extra far down the bore.

 

I think the NOS pistons you have do in fact have a 1.82 Compression/pin height. A lot of the replacement "283" pistons available these days come in at 1.80 (due to the .020 off the top). I have a set of NOS L-79 type, 327, factory forged, domed pistons with the "flaking" also. Post what you come up with in dealing with that problem. I was going to stick a brass wire, wire wheel on the bench grinder, and have at it. Butch/56sedandelivery.

 

Hey!!!! Did you ever get a response from that E-Bay seller? I finally got one 2 days ago, long after the auction ended, and they are UNDER FOUR INCH BORE!!! Score one for the good guys. Just thought I'd let you know. Butch/56sedandelivery.

 

When he did answer he said 2 sets were sold pending sale so he only had 1 single left. Did you win them at least, I hope ?

 

Rene Garza?

 

Rene Garza? No, Gary Howe out of Gig Harbor, Wa.

The steel shim head gaskets from that auction arrived today; they ARE under 4" bore gaskets!!! I guess I should have bought 2 pair, or even all 5 he had. Ya' snooze, ya' lose. Butch/56sedandelivery.

 

Well if you bought one set, someone else bought another set and all he has is one left. How thick are those and do they have part #? And Butch, here is another question: obviously the smallest diameter bore and thinnest thickness gasket is best. But if you had to choose, what would be the thickest one you would go with ? I have found a gasket that has a 3.84 bore but it is .039 thick. I have also found a 3.87 bore that is .028 thick. More enlightening please !

 

.039 gasket is 7.4cc and .028 gasket is 5.4 cc. On any gasket that is close to correct for your bore, the thickness will be more important. I'd use the .028 and deck the block to get the squish you want.

 

They have two different numbers of GM14085906 on one, X10292 (brand ???), one is black, the other silver. They are identical other than the numbers. These were described as being .018 compressed thickness. the composition gasket set I have is .028 compressed thickness. I'd go with the thinnest you have available also. Butch/56sedandelivery.

 

UPDATE: haven't done much do to fixing up the house because we thought we were going to sell but now we are staying and adding on which will also include a brand new garage ! The engine build is still going to go on but I don't want to jinx it, so there will be a very cool turn of events once I get my hands on some parts. Pics to follow tomorrow. Cross your fingers and hope I get this ! I think I may have finally found one of those "too good to be true" deals that is actually true !

 

Small Cube Build......cool... I have blocks, rods and a set of NOS domed 283 pistons. If you get an early block, there a some that can go 4" with no problem, then you can run std 302 type pistons.

 

Good luck with your build....I happen to be a convert of these little V8's.

I bought my '55 265 complete.......didn't do anything to it other than take a compression check.
It's now in my '32 pickup and running great.