Pontiac 455 cam recommendation

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tjs44
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Re: Pontiac 455 cam recommendation

Post by tjs44 » Fri Oct 14, 2016 7:20 pm

Guys,im not the sharpest tool in the shed BUT I drive a lot of pontiacs on the street from a 366 NASCAR tunnel port engine to 455s with all diff heads.This guy is looking for a street engine to work with power brakes and from what I get drive well.In the last almost 20 years I have street driven cams from 108 to 113 and duration at 50 up to 252-260.ALL have been stick shift cars some with 4 speeds but most with TKO 5 speeds.With a iron headed 455 and 9.5 CR on out CA 91 piss gas a 245-252@50 on a 110 got me one really solid power brake stop without a vac assist.When going wider to a 112 it was better.With a 250-250 on a 108 with a 3.90 rear gear it did not like being under 1800 rpms around town in 5th gear and had to be pulled back a gear.236-242 ish on a 112 seems to be a sweet spot for my street driving with a OD trans for me.Have not given a tinkers damn about peak HP as all the engines are street drivers with street manners.I built one 455 with a Summit 2801(RA III cam) straight up.It pumped 200 and had to ad race gas to street drive it.Im only giving my experience about street driving these engine for the last 20 years.Post on.Tom

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Re: Pontiac 455 cam recommendation

Post by Walter R. Malik » Fri Oct 14, 2016 8:03 pm

pmd400 wrote:How would 276/268 adv. 233/227 at .050, .504/.489 lift with 1.5 rockers lunati voodoo sound.
I'm thinking 106lsa ground on a 102icl
In my opinion, to big for an often driven around town vehicle; (unless you put a bunch more gear in the back).
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Re: Pontiac 455 cam recommendation

Post by 427dart » Fri Oct 14, 2016 8:07 pm

Compared to all the "new" way to design a cam for a particular engine...were all the factory engineers just guessing when developing a cam for engines back in the late 60's? Pontiac had Malcom McKellar design their factory race and street cams...one of the best back then.

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Re: Pontiac 455 cam recommendation

Post by tjs44 » Fri Oct 14, 2016 8:20 pm

The cam that really gets a lot use is the RA IV with rhodes lifters.I just never liked them.I have found the hyd roller cams to my liking and no breakin issue with FT lifters.Way more money though.Tom

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Re: Pontiac 455 cam recommendation

Post by GARY C » Fri Oct 14, 2016 9:08 pm

pmd400 wrote:How would 276/268 adv. 233/227 at .050, .504/.489 lift with 1.5 rockers lunati voodoo sound.
I'm thinking 106lsa ground on a 102icl
I personally would not go negative on the exhaust unless I was going to dyno test it against something else. If it was me I would go with the 268 lobe on a 106 in at a 102, keep in mind that your 1.65 rocker will effectively add about 2 to 2.5 degrees to your .050 numbers.

I tend to er on the moderate side for a street cam, if it's a little small you might loose a little hp at the top of the rpm range but if it's to big you risk loosing both tq and hp everywhere except for the top part of the rpm range.
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Re: Pontiac 455 cam recommendation

Post by pmd400 » Sat Oct 15, 2016 12:59 am

How about for the intake use an comp xe, 274 at 0.006, 230 at .050, .325 tappet lift.
Exhaust using comp magnum, 276 at .006, 226 at 050, .309 tappet lift.
According to comp both lobe families are asymmetrical. The xe is much steeper on the opening then closing ramp while the magnum is much closer to being equal

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Re: Pontiac 455 cam recommendation

Post by wyrmrider » Sat Oct 15, 2016 1:25 am

go back and reread the OP's first post
240 or 270 gear
under 5500 rpm
what makes you think a 230 degree cam would be any fun?

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Re: Pontiac 455 cam recommendation

Post by GARY C » Sat Oct 15, 2016 3:24 am

pmd400 wrote:How about for the intake use an comp xe, 274 at 0.006, 230 at .050, .325 tappet lift.
Exhaust using comp magnum, 276 at .006, 226 at 050, .309 tappet lift.
According to comp both lobe families are asymmetrical. The xe is much steeper on the opening then closing ramp while the magnum is much closer to being equal
I like that one, fast intake with slow exhaust. It may be worth while to pay a little extra for the treated core...I never have but everyone says it's good insurance. I did groove my lifter bores on my Pontiac with Comps grooving tool, I don't know how much it helps but I did it anyway.
I ran a Comps XE 284/240 in a 9.5:1 468 BBC in my 77 T/A with a set of well worked over oval ports a performer rpm with an old holley 800 dp I wished I had chose the 274 because the 284 was a bit much at idle due to a very tight 11" converter only 1000 over stock stall but it was stupid fast even with a 3.08 gear and a 295-50-15-tire it was traction limited even rolling at a good pace.
MAKE SURE! you have sub frame connectors! I have seen guys twist these cars bad enough that the door will not close, also as well as a quality slapper bar like Competition Engineering or Cal Tracks. Big Block tq will find any weak links. :D
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Re: Pontiac 455 cam recommendation

Post by Geoff2 » Sat Oct 15, 2016 4:00 am

Yes, Pontiac 14* heads have a 135* sweeping bend in the exh port. I do not see this as being so bad... Whether by accident or design, it positions the exh port exit interface with headers at a less sharp/more favourable angle. Compare the Pontiac port to Mopar Wedge, SBC exh ports, that have upward pointing exh port exits & a sharper angle entering the header.

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Re: Pontiac 455 cam recommendation

Post by Keith Morganstein » Sat Oct 15, 2016 8:43 am

I don't have the cam card in front of me.
Mike Jones (jones cams) made me Hyd roller cams that has worked well in pontiac street applications.

It's around 226/226, 525/525 on 108 or 110. Different lobes int and exhaust. I think you would be happy with that.

Your not going to do as well picking and choosing lobes as working with the cam designer. I would avoid comp, esp a flat Hyd or street roller. Much better off working with Mike jones (or Chris Straub etc...) for a little more, you'll get something made for you and good quality.
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Re: Pontiac 455 cam recommendation

Post by tjs44 » Sat Oct 15, 2016 3:44 pm

The only reason is I have driven a lot of 455s with 230s duration.The long arm likes them.The 3 3/4 stroke 400s dont.Tom

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Re: Pontiac 455 cam recommendation

Post by Kenny M » Sat Oct 15, 2016 4:37 pm

Looks to me like you want a cost effective camshaft. I have had great tire blowing,very strong pull to 5500 on 455 9 to 1 motors with these two camshafts. Ether one will more than fit your engine combo and make you smile without hurting your wallet.
Crower 60916 278-289-221-229 460 470 112 in @108
Summit 2802 282-292-224-234 470 490 114 in @ 109

Pontiac/Olds/Buicks.. My personal experience with OEM Heads.. Wider seat Duration and Wider Center has given me the best results. Plus they don't rattle like a sold roller:)

Kenny

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Re: Pontiac 455 cam recommendation

Post by GARY C » Sat Oct 15, 2016 5:09 pm

Kenny M wrote:Looks to me like you want a cost effective camshaft. I have had great tire blowing,very strong pull to 5500 on 455 9 to 1 motors with these two camshafts. Ether one will more than fit your engine combo and make you smile without hurting your wallet.
Crower 60916 278-289-221-229 460 470 112 in @108
Summit 2802 282-292-224-234 470 490 114 in @ 109

Pontiac/Olds/Buicks.. My personal experience with OEM Heads.. Wider seat Duration and Wider Center has given me the best results. Plus they don't rattle like a sold roller:)

Kenny
What did you experience when you compared a tight LSA cam against a wide LSA cam?
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Re: Pontiac 455 cam recommendation

Post by MadBill » Sat Oct 15, 2016 9:45 pm

427dart wrote:Compared to all the "new" way to design a cam for a particular engine...were all the factory engineers just guessing when developing a cam for engines back in the late 60's? Pontiac had Malcom McKellar design their factory race and street cams...one of the best back then.
Surprisingly, the answer is at least partly "yes"! I read an article many years ago re a race cam development approach Pontiac tried using the "Cuban Square" (or some similar name) They created some kind of geometric figure and used it to guide them in shifting around open/close events in search of the optimum combo.
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Re: Pontiac 455 cam recommendation

Post by wyrmrider » Sat Oct 15, 2016 11:36 pm

I never worked with KcKeller who had an excellent reputation but Chrysler's cam guy- in the South did his by hand- I've been trying to come up with his name but am embarrassed to say it does not come up-- Camcraft?
that said
OP would be well ahead to use a HR, the Jones HR but maybe one size smaller due to the compression and axle
even that Hot Rod article shows the difference
With a MOPAR size lifter you can come close to HR profile but with all the durability problems, with the chevy size lifter there is no comparison HR all the way

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