[Squidward]

I'm a big fan of Freiburger, Roadkill, Vice Grip, etc. It fits into my zone.

A recent episode has Freiburger fixing up a 71 T37 Lemans with a 400. The 400 was rebuilt with forged pistons, D port E heads, and a Comp Thumpr 235/249 cam with a 107 LSA. It made 440hp on the dyno.

https://youtu.be/k6-iYOcPvd8?si=2SqSyE9AL7lFZz0O&t=1483 (start at 24:43).

So question: Would you run this cam? It seems like a whole bunch of cam for a 400. It was described as "a very mild street cruisable Pontiac 400".

Idk. Doesn't seem so "very mild street cruisable Pontiac 400" to me.

[Formulas]

Is Motortrend back to producing new content?

You have to remember they are not really vested in best outcomes unless its their darling engines and they have sponsors tugging on their shirts and a crowd to entertain

440HP sounds weak for a 400 with good heads the thumper is a sound based offering

[steve25]

I guess this was the mother thumper cam?

You did not mention the compression, but I can only assume that it was on the low side of what was needed for that duration that Cam judging by the weak hp numbers made for having aftermarket heads on it,

A good bowl porting job on iron heads a long with less Cam will get you those hp numbers !

And yes without at least 10.5 to 1 compression I would not want that Cam in my stock stroke 400 unless I had 4.11 or steeper rear gears .

[Formulajones]

Freiburger is much like myself and a few others I know, when it comes to cams and what is a mild driver and what is radical. So it's hard to judge people when they say they want a "mild" cam or a "nice daily driver" cam. Because other peoples idea of what is mild is very different from what I consider mild or what Freiburger considers mild.

Some of this has to do with how the cam was installed (ICL) as most people don't even check that. Some of it has to do with how well of a tuner someone is. Some people build engines like this and then want to set base timing at 10 degrees, won't run vacuum advance, and/or have no clue how to really set one up. And/or they don't understand carbs enough to make the necessary changes. Then it runs like crap and they immediately blame the cam as being too radical.

I've run the mother thumper cam in a 406 and even though it was a 4 speed car and had manual brakes, I found the camshaft very drivable, it behaved well and would run in phoenix traffic all day without complaint. It doesn't really make enough vacuum in a 400 to run power brakes and for many that's a no go right from the start. So there's that. Otherwise I found it worked well on the street.

I've noticed when Freiburger is dynoing stuff like a 350 sbc for instance that has something like a 224 or 230 @ .050 cam in it he calls it a baby cam. And it is in my opinion as well. Especially if it's on a 110 or 112 lsa. That's still typically tame enough to run power brakes in a 350. It's not until you step it up to a cam in the upper 230's or 240's that Freiburger starts to get excited.

[Jay S]

There was a local guy to me that had the next size down thumper HR cam in a 400 with round port E heads. My friend built it, was about 10.7 compression. It was right around 350HP on a wheel dyno thru mufflers. It was a 4 speed car, maybe 420-430 ish on an engine dyno. Did ok, not great. He pulled it and built a stroker.

[PontiacHO]

Who’s paying him? Sponsors. Comp Cams. That’s a cruise the drive in cam. Noisy but not really a power making cam.

[chiphead]

I've seen that car on his FB page. I'd expect that cam to be peaky and have a rough idle. FormulaJones, what intake, compression and idle vacuum did your engine have? What was powerband?

The fuel line routing looks like a AVS carb. Does he just bolt sponsor parts together or what? I am happy that at least he kept the car Pontiac and didn't go LSX bellybutton.

[ta man]

Cam is waste with those heads, good for the dairy dip or if you get your parts free from the sponsor. 490 /475 lift is the sad part.

[72projectbird]

Personally, no I wouldn't run it. That said, it's not the worst you could throw in a 400. At least it's not the stereotypical "put an 068 in it" build.

[Tom Pugh]

Originally Posted by PontiacHO

Who’s paying him? Sponsors. Comp Cams. That’s a cruise the drive in cam. Noisy but not really a power making cam.

exactly, those cams are for posers not power...

[PAUL K]

In general a tighter LSA will improve midrange power. Added exhaust duration will extend the power range.

[post toastie]

Originally Posted by Formulas

Is Motortrend back to producing new content?

You have to remember they are not really vested in best outcomes unless its their darling engines and they have sponsors tugging on their shirts and a crowd to entertain

440HP sounds weak for a 400 with good heads the thumper is a sound based offering

It's the D/F david freiburger's own utube channel

[post toastie]

interesting side note at 1:04 in the video freiburger talks about how his father had a hand in the 68 GTO tire iron commercials

[Formulajones]

Originally Posted by chiphead

I've seen that car on his FB page. I'd expect that cam to be peaky and have a rough idle. FormulaJones, what intake, compression and idle vacuum did your engine have? What was powerband?
.

I ran an rpm air gap intake on that one, compression was 10.3:1 with iron heads and I ran it on 91 octane. It made good power off idle to 5800 or so. I shifted it at 6000 quite a bit but it didn't care if I short shifted at 5500 either. Like Paul K said they make great mid range power. It's very snappy right off idle. They are originally designed for round round cars that need good power off the turns. The peak dyno numbers probably don't really show or give the impression it's a power house but peak is only part of the story. I didn't watch the video or see what freiburger made with his but the dyno won't show you how well it drives or how the mid range feels when it's actually in the car. Total blast with a 4 speed.

[Nobuddy]

Originally Posted by Tom Pugh

exactly, those cams are for posers not power...

So I guess that makes it a great cam for him.

[72projectbird]

Originally Posted by Nobuddy

So I guess that makes it a great cam for him.

The guy owns some pretty awesome and quick cars. You might not like him, but I'd hardly call him a poser.

[promptcritical]

Nope.

[Steve C.]

Early development came from road race applications that needed a very wide power range to allow them to come out of the corners.
Someone liked the associated sound of these road race cams.
Fast forward and Bingo... they refined and developed the Thumper series for many Hot Rodders who actually enjoy the sound of a rowdy idle on their street cars.


.

[Formulajones]

He's built some neat chit, and he's not afraid to drive them either, hardly a poser. That's what I call a real car guy.

Most just build them and then stare at it.

[Squidward]

Originally Posted by Formulajones

He's built some neat chit, and he's not afraid to drive them either, hardly a poser. That's what I call a real car guy.

Most just build them and then stare at it.

I like all the replies and discussion. Broadening my understanding.

Vacuum for power brakes or running a vacuum modulator on an automatic is what had my initial concern, or the need for way deep gears or hi stall.

It just seemed a little for a stated mild street cruisability, which is highly individual and subjective.

I've always like DF. Loved him at Car Craft back in the day. I loved the content in that magazine and the "go fast for cheap" mentality, with attention to aesthetics not very much required.

I would road trip, get greasy, and drink beer with DF and Dulcich. Seem like cool dudes. If the Duct Tape Drags take place down in Tucson this year, I might have to road trip down there.