Doug1964

I am rebuilding a small journal 1966 327 engine for my 1960 corvette. I already have the block, machined .060 over. I am using "461" camel hump heads with the 1.94" intake valves. I have a steel small journal crank 10/10 under. I am trying to decide whether I should build the engine similar to an L79 with domed pistons and 10.5-11/1 compression and use an l79 style "151" grind camshaft or should I just use 9-1 flat top pistons and use a slightly more modern cam like High Energy 268 or Elgin E-1065-P. I know when I ask this question, I could and probably will get back a hundred different suggestions regarding cam and piston combinations and other engine performance suggestions. However, the question I am trying to decide is more basic. The car has a posi-traction 3.7 rear with a close ratio 4 speed. I definitely want to use pump gas and I want a very drivable street car. Given my parameters of pump gas and daily driver, if I go with a high compression engine, It is my understanding that I must use a cam like an L79 151 grind that has a wide lobe separation angle that will bleed down much of the compression. If I go with the flat top pistons, detonation is no problem and I can choose from a much larger pool of cams, is this correct so far. I guess the question is if I go with the 9-1 cr pistons will I be able to get enough performance that the engine still has a muscle car sound and performance, or am I going to regret that I do not have higher compression and feel that I have a dog of an engine. This may help also, the reason for the rebuild is that the car currently has a low hp non original 283 in it that has good sound with the off road exhausts but lacks the spunk to spin the rear wheels. Any comments or suggestions are appreciated. Thanks Doug.

69ttop502

I would cc your heads first to see where you are starting. I just finished a rebuild of my original 62 340 horse engine. My heads had been milled in a previous rebuild so ended up milling stock domed pistons to "0" to just get it down to 10.5 to 1. Measure your deck clearances as well. Those measurements will give you the direction you need to go to achieve your compression goals.

Personally I would go with the SHP stock engine and components. Maybe a Holley LT-1 clone intake and a 500cfm Holley. Do not rule out one of the three stock solid lifter cams either. I went with the LT-1 cam in my build. Haven't driven the car yet but it sure sounded great on the dyno. The long clearance ramps on the SHP cams lets you get away with some compression, and the solids shouldn't have problems even with today's oil given the low spring pressures required. You have my vote!

A solid SHP cam with 10.5 to one compression and your off road mufflers will sound great and would be a great combo and should last forever and still spin to 7000, which mine did on the dyno. And will still run on pump gas. The L79 cam would work great as well, but would probably stay closer to 10 to 1 on compression to be safe.

OC-1

best engine ever made is the 327/300....had flattop pistons and a 10:1 comp ratio...was the high performance engine of that series vs the special hi perf.

Well mannered, great driver that needs no attention. No guessing, no fuss, no muss.

Pocket port heads, make sure distrib is set up right and some 3:36 gears for a highway cruiser. Or whatever gear you want for your intended use.

Filler up with regular.

woodsdesign

I did the same build on my 327. (except for .30 over) and used flat top pistons and a Stock L-79 cam. It ran OK but not exactly what I wanted. Maybe a piston with a smaller dome would be a good compromise. I think picking the right cam to match would also be a wise move.
Bottom line, don't just change the pistons. I wound up putting the 327 in the corner and dropping in a SBC 400

Doug1964

Woods Thanks for the reply. I think my choice is either high compression pistons with the L79 cam or flat top pistons with a more modern cam. If I understand correctly how all this works, I can understand why you would not be satisfied with flat top piston using the L79 cam. The L79 cam with the flat top pistons probably resulted in a too low dynamic compression. I understand the L79 cam likes compression above 10.5 to 1.

I guess another way to ask my question is as follows. If I use the speed pro L2166Nf domed pistons and an L79 cam like elgin E-903-P ("151" clone), and my engine has a static CR of about 10.7 to 1, am I going to be happy with the engine's street manners and the ability to run pump gas?

MikeM

I've put the L-79 cam in several 300/327's with the flat top pistons with good results. The 097 cam works the same way. If you use the 30-30 cam, go with the pop ups by all means. Bottom line to me is use the pop up pistons with whatever OEM stock cam you use.

I don't like the LT1 cam or the 350/350 cam.

I'd avoid the aftermarket "modern" cams like the plague if they require heavier valve springs than OEM. Guys that use them seem to be lining up here wondering what kind of high priced, specialized motor oil to use or worse, they're screaming for help because they rounded a cam lobe.

I use 89 octane E 10 in two of my advertised 11.5/1 SBC's. One with the 097 cam, the other with the L 79 cam. No reason I couldn't do the same with my now being built SBC with the 30-30 cam.

Doug1964

Mike, I am convinced. I will stay with the pop up pistons I currently have on hand with 5.3 cc domes. Do you know if the elgin e903p cam is true to the L79 151 cam specs. It was shipped to me as L79 equivalent. I was expecting a melling cam the specs for which I previously checked and received the Elgin 903 instead. I am looking for the specs now. Should I send the cam back and ask for a substitute which is a true L79 spec and if so, which L79 version cam should I go with?

MikeM

I have heard that Elgin makes an exact copy of the 097 cam. Don't know for sure and I don't know anything about their 151 cam.

Speed Pro makes a direct copy of the 151 cam.

One hint as to whether or not the cam is an exact copy is whether or not the manuf. recommends "stock" valve springs. Not always true but something to think about.