[scott70]

Originally Posted by Jay S

I like Powell a lot, but it is a pretty big assumption that 330 cfm is needed for turning 5500 with 460 CID. That is more of a modern engine family way thinking for an LS, Gen 3 Hemi, or some Ford’s. Even on a modern engine platform it is a big stretch, that is well over 130 % VE.

One of the guys on PY recently dynoed in at 490 HP@5100 with his 461 Pontiac with 242 CFM D ports and 560+ lbs of tq. It was a Bullet HR and 236/[email protected]”. With a single plane intake, more carb and bigger headers, it even would have made peak power at close to 5500 with those 242 cfm heads.

Very similar to mine. 254cfm iron heads, iron intake, qjet, 232/241 @ 050 hft,,112 LS. 491 hp at 5200, 570 trq at 3100 rpms.

[mgarblik]

I also enjoy the Powell Machine videos, his general attitude and the skills he displays. His knowledge base is skewed toward the LS platform, not to say he isn't a fine machinist. His recommended cam may work as advertised, but every time I try a 110 or tighter LSA, I end up regretting it in a Pontiac street application. Not being a cam designer, I can't explain why, but the wider LSA cams with identical or similar profiles always seem to have better street manners and generally better overall results on the dyno. This is not the case with other platform engines consistently like a Pontiac. Did you happen to talk to Tim Goolsby @ Ultradyne/Bullet for a recommendation? He has over 30 years experience and seems to really know the characteristics of Pontiac V-8's. I know an engine is just an air pump and the cam doesn't know what engine it's going into. But that's really not the whole picture.

[Skippy597]

Thanks Jay, that's a good point. I just got done reading his Dyno thread and it is for sure a stout engine. I would assume with a nearly identical cam, and the rest of my setup I should probably be right where I want to be, maybe 520-530 @ 5300 ish. It's nice to bench race but even nicer to see real world results.

[Skip Fix]

The UD HFT 239/247 @0.050 in my 455 in the 78 is on a 112. The new SR Tim ground for me(UD lobes form Bullet) for a freshen up of a 400 for the street is on a 112. And he said he usually likes 110 or tighter but was what we felt would work on this.

[Skippy597]

I would love a custom cam by Tim but I have spent way too many attempts at trying to reach Bullet to no avail.

It's comical because for some reason every Dyno sheet I see of a Pontiac they prefer a 112-114 lsa. This completely goes against the thought that every engine is just a air pump of slightly different design and the generic cam recs like from David vizard don't apply. I'm still learning all this and this is my first performance Pontiac build.

If anyone has a trick at getting tim on the line I'd be more than open to it.

[JLMounce]

When I rebuilt my engine last year I talked with Bullet about getting a cam made. At the time their lead was over 8 weeks. I went with a comp spec'd by Jeff Kauffman that uses the newer Q series lobes (QNI in my case) and I've been really impressed with the cam. The valvetrain is MUCH quieter than the comp XFI lobe cam I had in the engine previously.

[grivera]

Originally Posted by JLMounce

The valvetrain is MUCH quieter than the comp XFI lobe cam I had in the engine previously.

Are the XFI lobes inherently noisy? I thought your valvetrain noise was attributed to the Lunati/Morel lifters, versus the new with Johnson lifters?

[JLMounce]

Originally Posted by grivera

Are the XFI lobes inherently noisy? I thought your valvetrain noise was attributed to the Lunati/Morel lifters, versus the new with Johnson lifters?

The lobe intensity on the XFI's is pretty aggressive. They likely exacerbated the noise issues that was inherent with my Morel lifters.

If you do some searching on the XFI lobes, it's a somewhat common complaint that it produces a noisy valvetrain. The QNI lobes on my current cam, although having more lobe lift are less aggressive on and off the ramp. Comp developed this lobe profile specifically with quiet valvetrain in mind.

[Jay S]

Many times Tim will suggest using a profile with less acceleration on the exhaust side for street longevity, that is another alteration that can be done. For instance that cam would probably look like 290/303 at .006” instead of 290/298, but the .050” spec is the same.

[Steve C.]

Jay's example...

Lobe HR303/3532
303
244
157
0.3532


.

[Dragncar]

I don't know but plenty of people have made some really good power on 455s- 461s with heads flowing less than 330cfm.
There seems to be more to it than cfm with a given ci. LS and sbc's have much lower drag and are slinging around much, mush lighter hunks of metal tha we are. Valve spring pressure can be a lot lighter too when parts do not weigh so much.
Tim, keep trying. He can be hard to get ahold of but is worth the wait.

[grivera]

Curious how noisy the XFI lobe cam would be with the Johnson lifters. I have KRE HR242 on the shelf, which may be XFI lobes.

[JLMounce]

Depending on the age, yes it's likely that cam has XFI lobes. You should be able to cross reference the lobe from your cam card.

With a good quality lifter, I would bet that you still hear the valves clicking as they slam shut against the seats.

That cam was in my engine for about 8 years and a decent amount of miles. When Jeff went through my heads, there was no need to redo the seats. After 8 years of service the heads got Jeff's 310cfm port, new springs for the larger cam and seals.

Point being the XFI lobes may have been a bit noisy, but it wasn't causing any damage anywhere.

[Steve C.]

If it helps Tim Goolsby is, or was, at extention 102

https://www.bulletcams.com/



.

[Skip Fix]

Got my custom SR from Bullet recently in less than 2 weeks!

[lust4speed]

I'll bet that Powell saw the 3.36 rear gear along with the 2.52 low and compensated for it. Although the 230/245 spread is terribly wide and more suited for a really choked exhaust.

I like to stay at or under .600" lift on an engine that will see a lot of street miles. Maybe a little too conservative? Additional lift is pretty much free horsepower but the additional stresses start to worry me. Comments?

I believe that the Butler cam is slightly warmer that the Comp and with the little extra LSA should be just as streetable. Butler would be my first choice with Comp a very close second. I think Powell might have missed the mark on this one.

[ponjohn]

Originally Posted by lust4speed

I'll bet that Powell saw the 3.36 rear gear along with the 2.52 low and compensated for it. Although the 230/245 spread is terribly wide and more suited for a really choked exhaust.

I like to stay at or under .600" lift on an engine that will see a lot of street miles. Maybe a little too conservative? Additional lift is pretty much free horsepower but the additional stresses start to worry me. Comments?

I believe that the Butler cam is slightly warmer that the Comp and with the little extra LSA should be just as streetable. Butler would be my first choice with Comp a very close second. I think Powell might have missed the mark on this one.

I bet in Powells opinion the Pontiac exhaust is choked, probably compared to other cylinder heads.

[Skippy597]

I have tried reaching out to butler again to no avail. What time of day are you guys calling Tim at to reach him?

The butler cam seems pretty interesting to me I just don't want anything too big for the street with a stick car. I feel like the 236/242 comp is a decent compromise cam and a bunch of people running them with good results. If the consensus is the butler cam on a 113 isn't too big then I like the idea of going with it.

[AG]

Originally Posted by Skippy597

I have tried reaching out to butler again to no avail. What time of day are you guys calling Tim at to reach him?

The butler cam seems pretty interesting to me I just don't want anything too big for the street with a stick car. I feel like the 236/242 comp is a decent compromise cam and a bunch of people running them with good results. If the consensus is the butler cam on a 113 isn't too big then I like the idea of going with it.

Last time I spoke to Tim was 2022 when I bought a HR cam from him with head flow specs, engine size etc. I think your philosophical approach to cam size is sound and for me anything between 110-114 LSA for the street is fine unless it's full race. My race SR can is on a 110 LSA. I put an OF 235/245 HR cam in my brother's 464 CI on a 112 LSA and the motor performs very well.

[lust4speed]

While I have a favorite or two at Butler, all the techs are very good. If you keep ending up at voicemail when asking for Tim (who I haven't talked to), then I'd just say I have a cam question and asked to be connected to an available tech.