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Malibusurfer 09-01-2012 10:17 AM

327 power questions
 
Hi all,
2nd post... I am picking up my .60 over 327, so 337ci. I have a few questions and maybe some cam selection suggestion.
Motor is numbers matched 68' Camaro large journal 327.
Steel crank
Reconditioned stock rods
KB hyperutectic pistons
10.1 compression
Rotating assembly is balanced
Heads are camel hump 462, ported, polished 2.02 / 1.60
Intake/carb undetermined yet???? Ideas???
Going in a early 60's 1/2 pick up for weekend use, play... Builder believes we may be close to 375 hp with right combo...
Any ideas guys on intake, carb and cam...
Thanks

Malibusurfer 09-01-2012 10:21 AM

...looking for ****

Motor will have shorty headers to dual exhaust with H pipe.

ap72 09-01-2012 10:55 AM

Are you sure you really have 10:1? a LOT of "10:1" engines are actually closer to 9:1. It makes a big difference in cam selection. Being at 9:1 would probably be better for you anyway in this application.

Malibusurfer 09-01-2012 11:38 AM

Just got off phone with builder.. He says depending on gasket thickness i am gonna fall between 9.3-9.5 or so :1
I misunderstood what he had said a few months go...

ap72 09-01-2012 11:42 AM

If you have an engine builder, let him build the engine. If he's worth what you're paying him he should have no problem picking a camshaft.

Malibusurfer 09-01-2012 11:49 AM

We sat down a while at and talked about it, but he has had my motor for over a yer and a half + ( medical issues )... There is new stuff out and just wanted some input if I was behind in anything that would be a benefit to my build...

cdminter59 09-01-2012 01:11 PM

327 power questions
 
What type of cam are you considering Hydraulic, solid lifter, hydraulic roller, or mechanical roller? Is this going to be a street driven truck or race track? I will tell you now that a hydraulic or mechanical roller is big bucks. You have to buy a kit with any camshaft which consist of cam, lifters, valve springs, retainers,and locks. For the street cam 12-239-3 X4262H, 1300-5600 operating range, .462/.480 lift and 218*/226* duration, 2500-3000 stall converter, 385 hp@ 5500 rpms, Torque 409 @ 4000 rpms. 12-242-2 XE268H, 1600-5800 operating range, .447/.480 lift and 224/230 duration, 2500-3000 stall converter, 396 hp @ 6000 rpms, Torque 401 @ 4000 rpms. Edelbrock Performer Rpm Intake, Holley or Demon 750 CFM carburetor.

cdminter59 09-01-2012 01:24 PM

327 power questions
 
Now with a over-drive transmission you'll need the operating range of the cam to be in the cruise rpm. 55 mph-1500-1600 rpm/ cam op range 1300-5500 rpms. If your cams low op range is higher than your cruise rpm your engine will lug when in over-drive. I hope I am explaining this right.

Malibusurfer 09-01-2012 01:38 PM

Yes, the explanation makes sense... Motor is a standard hyd. Flat tappet deal... Truck is gonna just be a cruiser/driver, and very rarely tow my v-drive boat..
I know 327's love to rev... I,m thinking of about a 25-27 inch rear tire (265/50/15) and with a 700r, should I bump up gear to 4.??? I want to get the benefit of why I chose the 327... 6-6500k revs :)

vinniekq2 09-01-2012 03:29 PM

If you want a true 375 hp then use a solid lifter flat tappet or better, advertised duration will be close to 300 with .500 lift, intake centre line and lobe displacement angle tbd. for a truck,the RPM air gap is good enough and use a 750 carb,1,5/8 headers.

ap72 09-01-2012 06:59 PM

Quote:

Originally Posted by vinniekq2 (Post 1587590)
If you want a true 375 hp then use a solid lifter flat tappet or better, advertised duration will be close to 300 with .500 lift, intake centre line and lobe displacement angle tbd. for a truck,the RPM air gap is good enough and use a 750 carb,1,5/8 headers.

With that combo and those heads any duration more than about 225 at .050" on the intake will be a waste.

The absolute BIGGEST I would go is 225/230, the smallest I'd go is about 210/210. Get all the lift you can with reasonable durability.

vinniekq2 09-01-2012 07:06 PM

ap sometimes you make very good posts,sometimes you dont. 300 "advertised" and since when does time( duration) become not effective with any head? show the math,,,,

ap72 09-01-2012 08:42 PM

Quote:

Originally Posted by vinniekq2 (Post 1587649)
ap sometimes you make very good posts,sometimes you dont. 300 "advertised" and since when does time( duration) become not effective with any head? show the math,,,,

"advertised" duration is completely meaningless since it is not the same EVEN WITHIN THE SAME CAM COMPANY.

As for the math, on those heads you need to notice a few points. Flow, compression, and choke. Even assuming those 160cc heads were heavily ported and taken out to 180cc's you'll be choked around 5800 RPM in the pushrod pinch, assuming you flow enough to make power at that point (225cfm would be adequate and relatively easy to hit) and you have enough compression to make power at that RPM (9.5:1 is about right for that RPM and those chambers) then to make the most average power at those RPM you need to match the duration.

Since you're not working with a restricted intake nor a really good exhaust a 220-225 duration would provide about the duration you need for that RPM and power. With a good thorough job you can easily get over 400hp.

There is more definite math involved than these generalities but I don't feel like putting the effort forth to show it. A great basic website for related calculators though is Wallace Racing.

vinniekq2 09-01-2012 09:04 PM

In the late 70s when there were very few good heads,there were a lot of engines making power way beyond 7500 rpm. The 327 mouse has been doing this since it came out and is not, was not, and wont ever be limited to 5800 rpm or anywhere near there with stock heads. The 283 had even smaller heads and it can make close to 400 hp at 8,000 rpm and it does not use a 225 duration at 50 cam to do this.
There are better heads than old factory heads,no doubt!!!
Factory heads from the sixties will make power past 7,000 rpm in a 327!!!

Malibusurfer 09-01-2012 09:33 PM

The 462 heads are what I have for now, but would eventually like to bump to aluminum's eventually...
The 462's have been ported pretty good and polished by reputable guy in my area... They are fresh cut to 2.02 /1.60 (from 194's) screw in studs, guide plates, etc... They are getting done right to handle the most they can flow for their vintage....
I'd really like to get to 6-6500 or more if possible just for some adrenaline or even take to track to see what she does in 1/4, but mainly truck is a street cruiser...
Am I limited to my high rpm's by cam and trans and rear setup??? Would a built 350turbo be a better deal??? Truck will not see lots of highway miles, but now and again......
Frame on truck is getting boxed in and crown Vic panther front suspension, etc... So chassis should be able to handle what I have for motor....


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