We just got my engine dyno tuned, and I would like to know what you guys think about the results. I have a completely stock (rebuilt .30 over) 1966 396/360hp engine. We got all the components of the engine "period correct" and rebuit them so that has to be taken into consideration. The engine topped out at 357 hp with 434 torgue. My mechanic was expecting more hp, but he was happy with the torque. What do you guys think?
Thanks,
Bob

357 sounds pretty close to 360. if ya take into account the margin for error on the test, i would be pretty happy. 434 is plenty torque from a stock engine. if it looks completely stock (i assume that is what you wanted right?) then it is all good.

What are the cam specs for the 396/360HP?..are they the same as the later 68-70 L34's?

434 ft/lbs of torque for stock is pretty respectable

The cam is completely stock. Mike (my mechanic) is not available, but Mike Crown's cd says:
Lift: Int. 462; Ex 480; Duration: Int. 340; Ex. 336 and it's a mechanical lifter. I don't know how that compares to later years. Mike was real happy with the torque, but he thought he would get at least the same hp as the cubic inches (402) of the engine.
Thanks,
Bob

Are you sure it is mechanical lifter? I thought
360 hp engines had hydraulics.

bobstarap, The cam in the 360 H.P.- 396 is a hydraulic flat tappet design, not a mechanical flat tappet. This cam has very long advertised duration figures but has a .050 duration of 214/218, works very well for normal driving and gets very good gas mileage. I had a '68 350 H.P.- 396 Chevelle with stock 3.31 gears and it routinely got 19 MPG on the hiway.

You guys are, of course, right on the money. I read Mike Crown's info incorrectly. He does state that it's a hydrolic lifter. The 375hp is mechanical. Also, he says the Ex. on the Duration is 340 not 336. I've got 3.73 gears, but I will probably go to 3.31 eventually.
Thanks,
Bob

I think those results speak for themselves and that is an admirable approach to look into a "real" stock period correct engine.

The only question I have would be if the dyno run was performed with stock manifolds and an exhaust system or with dyno headers and either an open or very unrestricted exhaust?

357 hp is very good for a stock 396/360. Remember the original rating was SAE Gross which means it was done with a recurved distributor, non production carb and headers. As installed it was probably only about 300 hp.

The dyno was run with the stock manifolds and exhast system. Mike mentioned that a different updated/upgraded exhaust sytem, etc., would add a lot to the hp.
Thanks,
Bob

Bob,
I am also curious if that was with stock exhaust manifolds. (oops your reply beat me to it) I would also like to know what pistons were used (dome size/expected compression ratio). Sounds great!

have you ever thought about changing cams? Theres probably ALOT of power to be had there with no other changes and no one can see that at all!! Just a thought

The pistons have a 9.1 to 1 compression ratio, but I asked Mike to jump on this web site when he gets home and explain some details that I'm not too squared away on or wrong (ie the torque is 454 not 434).
Thanks,
Bob

my book has the 396 1966-69 360/350 hp engines listen with following parts.

holley carb
high lift hyd. cam
small port cast iron heads
10.25 to 1 comp.

high lift cam had .4614 inch lift intake, and .4800 inch lift exhaust.

factory high lift cam part number 3883986

.008-inch lift duration was 268/274

350 degrees of duration (including ramps) on the intake and 352 degrees on the exhaust (including ramps)

intake 20-68 and exhaust 74-20

duration @ .050 213/217

what carb did you use and intake casting number? do you know what jets was used to run in the carb........just curious of all the details....what was done to the heads? 3 angle valve job? or just a single seat cut?

sounds pretty good for a stock engine...

i have wanted to build an exact peroid correct 396 of about the same year and see how well one of those really could run other then hear or read about them.......

The intake manifold is part #3866948, I believe and the carb list # is 3419. Mike knows all the other stuff and will explain.
Thanks,
Bob

How many stock smallblocks can boast 400+ ft.lbs. of torque :D I love the bigblock. Great numbers graemlins/thumbsup.gif