Evening all. Looks like I need a rebore on my 327 as there seems to be a bit of rust on a couple of bores. Anybody got any advice on which ones I need as there seems plenty for sale at the likes of Summit/Speedway. Engine is a standard 67 327 but I am adding 461/462 heads with the 2.02/1.6 valves Was thinking of going +30 but don’t know if I need flat top/dished/domed Thanks for any help
I just bored my 65 small journal .030 over and installed flat tops so I could run pump gas with my 461 heads. You should measure your bores, then dingleberry or lightly hone till imperfections are gone then measure again to see if you need to bore. Most of the time if the engine was in running condition the ridge will determine how much you have to bore to achieve a good fit with no taper. The flat-top double eyebrow weight-matched cast aluminum pistons I put in worked well with cast iron rings, give plenty of power and compression. Sent from my iPhone using H.A.M.B.
I put Speed Pro L2166NF040 dome pistons in my .040 over 327. I runs great on Euro pump gas. 98 is perfect, 95 will work fine aswell if you are cruising or roadtripping. If you are racing or putting higher loads on the engine, I´d prefer 98 or higher .It is quite zippy too. My cr with milled 461 heads is at about 11.3:1 . I built this engine in 2004, still runs perfectly.
These are the Speed Pros in my 355 to give you an idea, 1/16" compression rings on the advice of my builder, 327 pistons with a 3.25 stroke may have a different compression height. https://www.summitracing.com/parts/slp-h100cp30/overview/make/chevrolet
Be looking at the Sealed Power L2166NF60 dome pistons. Obviously got flat tops in there at the moment. Just hope they’ll be ok to clear the 461 head valves.
I’ve seen these for sale. Just a decision on +40 or +60 https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.co.uk/ulk/itm/153225033789
Pulled the engine apart yesterday. Oh the joys Got the freeze plugs out to find something that looks like chocolate fudge in the waterways. Got the pistons out to find that all the bearings are shot and the rings on one piston siezed. Checked the number on the crank to find it’s a small journal forged steel, so that’s a goodun. So plans are- Rebore with +.40 dome pistons Camel hump heads(461) Comp Cams XE268H 1.5 roller rockers 3x2 intake with Holley 94’s Lake style headers
I would stay at +.030 if it will clean up, the +.040 piston is what my 327 required to clean up. This was done many years ago when TRW still stocked them, they were forged with 11.25/1 compression ratio which is the oem c.r. on the 327/350 hp engines. Regardless of brand; I personally would use a forged piston if available without having to go with custom pistons but that's just me, either way, most people will tell you the extra cost is not justified for a street engine.
A very wise engine builder and SS racer and record holder once told me "go the minimum amount over like .010" over if you can, this way you can get another 2 or 3 rebuilds out of your block. The 4 or so cu.in. is meaningless. Pat
Looking at the .40 pistons like ”Baumi” said, it give me a CR if 10.35 with the 461 heads. Think the pistons I’ve seen are forged
Yes, they are. And they are good quality too. Speed Pro is in fact TRW. These L2166NF pistons come with Teflon (?)coated skirts.
PS: I can`t remember exactly how much my block was decked nor what amount my heads were cut. The block was certainly zero decked, I think the chambers ended up at around 60 cc instead of 64cc and I polished them. Today I would stay with 64 cc and put in a milder cam, back than I used to be young and wild, hahahaha
The L2166F or L2166NF are a 10.35 CR piston as used by the factory and aftermarket (TRW et al); I don't know where or how the 11.00 to 11.50 CR comes from (???). Even with 461 "X" heads, with 62 CC chambers instead of 64 CC chambers, it would't be much above 10.50, even with the a .060 maximum overbore (never seen these pistons over .060). Perhaps with block decking and head milling, or swapping to later heads or aftermarket heads with smaller chambers, the CR would be higher; not that we have the gasoline that would effectively work with that high of a CR; you guys in Europe at least have decent gasoline! My "spare" 327 is a .040 small journal block with these same pistons, and has been with me, first in my FED, then in my TRUCK temporarily, until it burnt an exhaust valve, then into my 63 Chevy II Station Wagon. It now sits in my shop/garage, completely fresh and ready to go, when finally needed. I did have to have one cylinder sleeved and then bored to .040 over with the last rebuild; it had a broken ring that wore a gouge in that cylinder. Has a Tri-Five clutch assembly, bell-housing, starter motor, 2.64 first gear Super T-10 4 -speed bolted to it, with rams horn manifolds, water pump, belt and alternator. Complete and ready to go, and I was planning on dropping it all into my 56 Sedan Delivery, but plans seem to have changed somewhat; who knows, it may still happen? I just hope it does't become part of my "estate". It seems like I have wound up with a LOT of 327 specific parts, but I really did't intend for that to happen. I may be building a large journal 327 based on a 350 4 bolt block, and another set of 461 heads I have, just to use some of all these parts I have. Most guys seem to worship the 283's, and I really don't know how or why the 327 has almost taken over my little shop/garage. It's really not a bad thing at all however; everyone has a 350 these days it seems. I am Butch/56sedandelivery.
For all the aggro this has given me so far, I wish I’d just bought a known good running 350. Only bought this off a friend of mine as he said it was a good motor. At least when I’ve finished building it, I’ll know what I have and hopefully can rely on it being a decent motor. With about 350bhp it should move my Model A Coupe along just fine
Butch , you are certainly right about the CR, 10.35 sounds more realistic... I probably got that wrong after almost 15 years.
Butch My reference to the 11.25/1 c.r. was generic to any of the oem 327's with dome pistons, which was 11.00/1 for the 325 hp and higher 327's by my 67 shop manual. I do remember seeing the 11.25/1 callout somewhere, I'll have to look.
I usually read where these pistons are being sold used as 11.5:1 CR pistons (sometimes even 12.5:1, ???). Really, they only have a .125 dome, not a .250 or more dome that the aftermarket would ONLY supply. I think sometimes even the factory "fudged" on the CR specs on the SBC engines. Would they lie??? Of course not!!! RIGHT!!! And so, the "myth", is presented as "fact", and we buy into it. If you compare these pistons with aftermarket high compression pistons, it becomes apparent, someone is not telling the "full story". I've seen these pistons being sold on E-Bay, Craigs List, and other places, as 11.5:1-12.5:1 CR pistons. Some guys spout what they hear, and don't even really know what they're talking about; we all know who those guys are, and they're everywhere. This is really a Chevrolet/GM myth, that people have unfortunately bought into. There was a time that I thought these pistons were going to be taking my FED into the high eights (for Super Comp), when 9.23 was the lowest ET I managed. Like I said, 11:1, no way, unless there's a lot of carbon buildup, heads milled, decks cut, and "initiative 502" heavily factored into the equation (that I did not agree with or vote for, still do not agree with, and will never agree with). DDDenny, you don't have to "prove" anything to me me, and please, don't take my "opinions" personally; this is't what this is about! They are just way too small of a dome. Would Chevrolet "lie"? Yep, they did/do, and I bleed Chevrolet orange when cut! Yes, they did, totally, do, and continue to do so (just go into any dealership/shop-they all lie, all the makes/brands). But, that's the nature of the car industry. The factories had to provide enough to the customer base, to sell high performance cars, at really any cost, even to their own integrity, so a little lie here and there did't matter. I could be wrong, but that has happened many times before, and will happen many times again. My "spare" 327 is a .040 over, 10.35 CR pistoned, 461 "X" headed motor. The heads have very OLD technology, such as pinned studs, heavily polished chambers and ports; even the exhaust ports are completely ROUND and the intake side has very little room for gaskets to seal very well to. 62 CC chambers "originally", that are probably closer to 66-68 CC now, with the 10.35 pistons. I did't want to attempt to CC the heads, I did't really want to be disappointed. The engine had some HUGE domes when I bought it. But, it also did't have the aluminum rods the guy said it had; although the stock rods had been ground, lightened, and polished, and they were't even the better 2nd design rod. Everything was rusted up. Then I found out I could't get a decent priced, full floating pin, style piston. I wound up using the block and crank, and the BARE heads. Everything else had to be replaced. I gave the old pistons/rods to a circle track racer from my work (Antabuse patient-for alcohol mainatainence), and made his DAY!!! Then, I went on the hunt for some good, 2nd design , factory rods, and paid the machinist who had them to redo the big ends (Ken Liden Racing Engines in Everett, Wa). Pistons came from Jim Green's Performance Center in Lynnwood, Wa., and they hung them on the rods for "CHEAP". Flat tappet, mechanical lifter, Crower cam, lifters and springs, with all the valves redone (I think I got real lucky there). I traded parts, and swapped anything I had to finish assembling the engine. My girlfriend at the time (my wife now of 30 years now) probably thought I had lost my mind). Everything I did, or thought was about, was getting that engine together. Assembled the engine myself, and it was't even precision balanced!!! Built my own trans-brake equipped, shorty Powerglide transmission; (learned a LOT there), and rebuilt the FED from an real abortion of a RED "conversion" back to a FED. I'm pretty sure my girlfriend thought I was completely NUTS! But, she was there for my license runs, at what was then still called Seattle International Raceway, and at Bremerton Raceways, with the front-end easily 45 degrees in the air (I really needed wheelie bars!!!). (Wish I knew how to post pics , seriously, I don't need to know, I'd never get anything else done!) Anyway, this engine is with me for "life". I won't sell it, or give it away, or sell it, unless it's to give to my nephew, the son I never had!!!!! I am Butch/56sedandelivery.
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