Thread: 327 Performance options???

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I have a rebuilt 327 motor out of a 68 camaro #3914678. It has the stock camel hump heads. I was wanting to beef up the motor alittle, just for street racing or cruising, not a serious drag motor or anything.

Be sides a mild cam and intake, What can I do to help performance?

I have read that the stock 327 camel hump heads suck. I have a set of 350 heads # 3973487, they are 350 LT1 75cc. Can I swap out the camel hump heads for these 350 heads to increase HP?

Thanks in advamce for your help/suggestions

sanpedro

Who is saying that camel humps suck ??? Those camel hump heads are closed chamber at around 64 to 64 cc. They are the best shaped chamber to run on the small block because they produce 30 ft lb's more torque than the open chambers. Sure, they are over 40 years old and they are old teachnology, and a lot of people bad mouth them because of thier age and prone to cracking. These heads came with that 327 right ? Chances are that they are okay. And swapping to the 75cc open chamber heads will drop all 3 aspects, compression, torque and horsepower. They were made when cars used leaded gas, so the seats are unhardened, thats the only drawback, but it takes a long long time to chop out seats. Besides you are only using it as a fun car. So the unhardened seats will hardly be an issue if you take the trouble to add a little bit aof lead additive everytime you fill up.

I gather that you allready have the mild cam and intake.

Beef it up with

Headers
Holley 600 cfm vacume secondary carb with secodary metering block and center hung float bowls
Auto shift kit
An ignition with the ignition curve adjusted to your car and style of driving

Cool that was the type of advice I was looking for. Then I willl keep the heads that are on there.

Thanks for the info

Glad to help

The "camelhump", or "double bump" heads were the high performance offering for smallblocks. Those heads with slightly larger valves were used on the famous fuel injection motors for 375 HP, and with the smaller valves they still could make 350 factory horsepower in the Novas. They had larger ports than the lopo heads too. They were all I ever used, and I could hang with the big block muscle cars on any given day.

Thanks for the info

The 375 hp version of the engine came with a solid lifter 30/30 cam.

Originally Posted by NTFDAY

The 375 hp version of the engine came with a solid lifter 30/30 cam.

That was the 30 across cam wasn't it. What was the static compression ratio ? so that I can work out the dynamic compression ratio from the cam specs. If you have the cam specs taht would help to.

Originally Posted by southerner

That was the 30 across cam wasn't it. What was the static compression ratio ? so that I can work out the dynamic compression ratio from the cam specs. If you have the cam specs taht would help to.

I have the specs on the Isky version and as soon as I find the card I'll post it.

Found some RPO numbers for 3 327 engines, just need the fact sheets for each one now

RPO L75 327 cid 350 hp carbureted Holley 4 barrel
RPO L76 327 cid 365 hp carbureted Holley 4 barrel
RPO L84 327 cid 375 hp rochester mechanical fuel injection

Whichever way you look at it these are pretty impressive horsepower figures from a factory produced 327 from the mid 60's

Originally Posted by southerner

Who is saying that camel humps suck ??? Those camel hump heads are closed chamber at around 64 to 64 cc. They are the best shaped chamber to run on the small block because they produce 30 ft lb's more torque than the open chambers. Sure, they are over 40 years old and they are old teachnology, and a lot of people bad mouth them because of thier age and prone to cracking. These heads came with that 327 right ? Chances are that they are okay. And swapping to the 75cc open chamber heads will drop all 3 aspects, compression, torque and horsepower. They were made when cars used leaded gas, so the seats are unhardened, thats the only drawback, but it takes a long long time to chop out seats. Besides you are only using it as a fun car. So the unhardened seats will hardly be an issue if you take the trouble to add a little bit aof lead additive everytime you fill up.

I gather that you allready have the mild cam and intake.

Beef it up with

Headers
Holley 600 cfm vacume secondary carb with secodary metering block and center hung float bowls
Auto shift kit
An ignition with the ignition curve adjusted to your car and style of driving

I don't think I would say anything about producing 30 ft lbs. of torque.
It is kind of an exaggeration and there really are a lot of varibles.
Sometimes an engine really likes an open chamber head because the intake and exhaust valve are not shrouded as much.

Well the heads that he has got on that 327 are going to work a lot better than those open chamber heads that he has got sitting on the workshop floor. And those closed chamber heads produced up to 30 ft lb's of torque right across the engines rev range. If closed chambers are bad howcome world products make closed chamber SR torkers with 68 cc chambers out of cast iron ? Also all the mid sixtys small blocks made some respectable horsepower with closed chamber heads. Then along came 1971, with open chamber heads to drop the compresion ratios to reduce NOX emissions.... "Bang" all the engines right across the board lost up to 30 - 35 HP.

OKay guys I have another dumb question for you. I got a Harmonic Balancer with this motor but just wanted to doulbe check to see if is the right one. It "looks" correct for a gm but on the back it has "KOREA 5012475 169"

ANybody know if this is useable? if not will a balancer from a 305 work?

Thanks again for everyone help.

The 365-375 HP engines were either 11:1 or 11.5:1.

Welllllll, !!!, I suppose lots of GM parts are outsorced now and as long as it fits the crankshaft snugly the timing mark is in the right place. Check this by winding the motor over by hand to 1 TDC by using a piston stop in the sparkplug hole, you should see if the 0 on the timing marker lines up with the line on the harmonic balancer.

2 more points make sure that you have an internally balanced balancer, that means no counterweight on the balancer.

Is it an 8 inch or a 63/4 diameter balancer ?

Just a question totaly different from all this what kind of transmission are you running and what was the car type again ?