[406 ss monte]

tell me what you think of this combo

406 sbc
3.75 stroke
5.7 rods
flat top pistons (speed pro forged)
comp cams xs274s 236-242 @.050 .501-.510 lift 110/106
edelbrock performer rpm airgap intake
750 dp holley
AFR 195 eliminater's, 75cc chambers, 2.05-1.6
comp cams 1.52 roller rockers
10.40 compression
1 3/4 headers (hooker 2242)
3500 stall
350 turbo
3.42 gears
275/60-15 tires
85 ss monte carlo 3,500 lbs

any thoughts?

[DoubleVision]

Looks pretty good to me.

[machine shop tom]

Originally Posted by 406 ss monte

tell me what you think of this combo

406 sbc
3.75 stroke
5.7 rods
flat top pistons (speed pro forged)
comp cams xs274s 236-242 @.050 .501-.510 lift 110/106
edelbrock performer rpm airgap intake
750 dp holley
AFR 195 eliminater's, 75cc chambers, 2.05-1.6
comp cams 1.52 roller rockers
1 3/4 headers (hooker 2242)
3500 stall
350 turbo
3.42 gears
275/60-15 tires
85 ss monte carlo 3,500 lbs

any thoughts?

Should be ok, but watch your total timing. That cam with 9.25:1 or so will be sensitive to too much total advance. Try limiting it to no more than 34° all in at 2,500 rpm.

tom

[406 ss monte]

i figure the compression to be 10.41-1. 75cc chambers, 3.40cc valve releafs, .038 x 4.200 head gasket, .005 down in the hole. am i going to run into trouble with that cam & the compression? what should be done? thanks

[baddbob]

I bet that engine would handle a little more cam-something in the 240@.050 on the intake side. Also, don't the AFR 195's have an excellent intake to exhaust flow ratio? Maybe a single pattern cam would work better. The heads would also like more lift-.501/.510 isn't much area to take advantage of what those heads have to offer. JMO-maybe I'm way off base....

[machine shop tom]

Originally Posted by 406 ss monte

i figure the compression to be 10.28-1. 75cc chambers, 5cc valve releafs, .038x4.200 head gasket, .005 down in the hole. am i going to run into trouble with that cam & the compression? what should be done? thanks

OOPs, my bad. I had in my head an engine I did a few years ago that was identical except it had dished pistons and and XE274 cam I'm sorry. That XS274 will probably be OK with the aluminum heads, but I think badbob is on the right track about using a little more cam instead.

tom

[454C10]

I say.......

too much stall. 2600 to 2800 should be fine with that cam

not enough gear. 3.73 would be ideal

header tubes too big. 1-5/8 would be better

No need to use more duration on the exhaust side with those heads.

[406 ss monte]

i can have my stall speed changed.

3.73 gears would be better, but to be honest i've ran 3.73 & 3.42 gears & there isn't much at all difference imo.

why would the 1 5/8 headers be better? better torque?

what cam? the only single pattern cams i've seen is the comp cams magnums.
i want a solid lift cam.

i have comp cams 1.52 roller rockers, i could sell them & get some 1.6 rockers. i've thought about that too.

[454C10]

yes, better torque with the 1-5/8. Don't think you are at the point of needing 1-3/4 yet.

yes, the magnum cams are a single pattern. The 280s has 230/230 degrees at 0.050". However, the xs series have faster ramps than the old magnum cams. Faster ramps make more power but tend to wear quicker. The xs274s only has 6 degree more on the exhaust so it isn't that bad.

[baddbob]

Comp should have a single pattern solid cam in the 240-245ish@050 range with over .500 lift or you could use 1.6 rockers. In a 406 I see no reason to go any smaller unless you're running really low compression. A 406 swallows a cam this size like nothing and still makes plenty of torque for daily driving. A 292H (240@.050)made enough low end torque in one 406 I built that you could actually start from a stop in 3rd gear and this was with a Muncie and 3.08 gears in a 67 camaro with less compression than yours. Definately keep the 1 3/4 headers (if the rest of the exhaust system is efficient) because there's no performance gains going smaller-I've seen this with 350 engines also with more power from idle all the way up with the larger primaries. Another thing you should consider-call AFR and I bet you'll get some great cam recomendations and also thier confirmation on header size for those heads.

[406 ss monte]

i'm running a lunati 249-259 @.050" lift .543-.561 on a 106/104. i sold my dart 215 pro-1's in favor of getting the 195 afr's. they out flow the darts all around. the short block is still in the car. the 1 3/4 headers, 3500 stall, & 3.42 gears are part of my combo from that build. i have 3" pipe to the rear end going through terminator mufflers. the car is (was) plenty strong on bottom end. i just wanted more. it wont hurt me a bit to run this cam. it sounds great & runs good. i just never turn it over 5,500 rpm & thought i might be better going a lot smaller.

my pistons are speed pro L2489F30. i was off on the valve relief size. it's 3.40cc's which will make my compression 10.41.

[406 ss monte]

anybody? any suggestions?

[F-BIRD'88]

I run the comp Xe 284H cam in my 406 and it eats that up pretty good.
The 3500 stall in mine actual get around 3800rpm stall and could easily be stepped down to 3000rpm. Yours will be the same. You can either step up the cam to something close to 250@.050" or go down in stall speed as the motor makes a ton of torque once above 2800rpm.
you might as well keep the Lunati cam you already have. It will make more power within the rpm range you use now than the little comp Extreme solid.
Even with the Lunati cam specs these 406's are not rev ers at all. They are all about torque.
I agree with the post above, the small(er) XE S cam will put you right on the edge as far as cylinder pressure goes. You'll most likely find the top end falls off to quick too. A 1.6 rocker on your Lunati cam will help allow the AFR's to show their stuff with the higher net valve lift.

You can increase the carb cfm. a healthy 406 like yours is carb hungry with a 750cfm carb. A holley HP/Proform carb body swap upgrade is a good way to gain some CFM while keeping the same responsive 1.4" carb venturii size.

[Bowtie man]

Sounds good to me, would be nice to have a little lower gear to help that converter with the weight of the car.

[406 ss monte]

what intake should i use? i have an edelbrock victor jr, weiand team G, & a edelbrock rpm airgap?

f-bird, is their a better cam for my 406 than what i have?