[rascal455ho]

How would 290b do in 9.5-1 455 with iron heads(7k3)Has power drums but can upgrade if necessary.turbo 400 with coan 3200 conv

[ponjohn]

Any port work?

[rascal455ho]

Yes will have port work to 240-250

[TIN TIGR]

the 290b6 is a winner..it just works..i have used this grind in several engines and never been disappointed..beware of torque..

[440GP69]

Yep thats a Great Low Compression Cam for sure! Needs gears like 3.55-3.73 and a Torquer 2 intake and 850 min carb, Bigger the better on the headers, grind them heads for 1.65 rockers and use em! Goodluck! FWIW down the road might consider more converter from Continental JM2

[performerrpm]

ive always kinda thought........and even read here that the 290b-6 really needy in the 11 or 12.1 cr area. i started to run it myself before i changing to solid roller. ask py member 6567gto about it he has it in his 65 or did. sounds kick a** though he has a youtube video of it

[screamingchief]

Nah,does'nt need that much CR.

I personally would opt for the 300b6 with combos that are over 11:1 CR.

The tight LSA and realitvely early IC event of the 290b6 can build a lot of cylinder pressure for a given CR,and with the higher compression ratios that can get out of control if your not too careful.

My working CR "range" for the 290b6 is 9.5:1 to 11.0:1.

[ta man]

I'll be using the 290b with either ported 6x heads at 93 cc or sd kre 290 aluminum heads in a 462.With 1.5 rockers where would the horsepower peak?Not meaning to hijack thread just curious.looking to keep revs well under 6000 rpm.

[Steve C.]

5700 with RPM intake

[Steve C.]

I'll take a stab at it....

4.210 stroke / 9.5 cr / 180 cc intake runner / Performer RPM intake / 800 cfm carb = peak power at 5700 rpm

[screamingchief]

That sounds about right for this combo I guess,but no doubt it will still be pulling plenty strong up to around 6500 or so RPM's regardless.

But it wont mind staying under 6000 RPMs either,should do fine.

Just understand that this particular cam tends to "hold onto the curve after the peak" better than most other "tight" LSA cams do.

That is mostly due to the big I-E duration split and ample overlap.

Where one installs the cam will influence this a bit too,but we already know that,right?

[ta man]

Thanks

[llwta76]

SC: how do you rate the 288/296 UD solid flat(/108 ls ) with the 290b?

[goatman65]

I've read that this is a 'peaky' cam.What is meant by a peaky cam?

[Mr Twister]

Who makes this cam?

[goatman65]

Comp cams

[screamingchief]

Originally Posted by llwta76

SC: how do you rate the 288/296 UD solid flat(/108 ls ) with the 290b?

The UD "acts" slightly smaller in my experience when compared to a 290b6.

Mostly due to having slightly less total overlap.

The UD 288/296 solid has 76° total overlap,and the 290b6 has 85° total overlap.

The UD also has slightly less overlap @ .050" too (appx. 5.5° less).

This is mostly due to the tighter LSA of the 290b6,as well as the greater I-E duration split of said 290b6.

I-E split for the UD is 12° advertised,and 8° @ .050".
I-E split for the 290b6 is 14° advertised,and 11° @ .050".

By the virtue of those two items (overlap & I-E split),the 290b6 should hold onto the power curve after peak power better than the UD 288/296,but that will always be influenced by each given combo as well,so there are no absolute truths on all this.

Both are very good cams though,and each will favor certain combos.

As one adds more stroke,or vastly increases the engines breathing capabillities,often the need for more overlap diminishes somewhat.

But it can also be dependant on the intended RPM range one is shooting for with a given cam choice as well.

Anything that adds dwell @ TDC can also influence the overlap affect on the engines breathing process.

That's why I said in another 290b6 thread here that it's entirely possible to have too much of a good thing (was also discussing the similar crower #60353 solid).

Really big CID engines,with well done high CFM heads,operating in a moderate RPM range generally wont need as much overlap as a smaller engine with lesser heads operating at a very high RPM range,as those big engines with good heads can easily fill the cylinders without the added help from the exhaust scavenging.

And we must not forget the compression ratio can play into this as well,but that is a whole other can of worms...

HTH.