360 Build Advice

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The biggest noticeable effect I could think of, compared to the other, will be idle...106 LSA will lope pretty well...probably kinda choppy, but would likely sound pretty damn good and have some snappy throttle response if you have the rest of the combo set up and dialed in correctly.
 
If my math is correct, this cam has 78.5 overlap. Any concern running that much overlap on a street only with my combo?
 
Regardless of your intended use, this cam will chop with the tight LSA and timing events. I would say you could probably advance the cam, but if you're running a zero decked flattop piston and smallish chambers, it should have plenty of compression. You'll have to mess around with your carb a little-that cam will probably be a little lacking on the idle vacuum and will necessitate lighter step up springs.
 
Will not be a daily driver. Summer/weekends only and will never see the track. Gonna make a head change to the RHS X heads soon so comp ratio should drop to something a little more user friendly.
 
The static compression shouldn't be too much trouble with the cam choice and a close quench...
 
Got it.

As far as advancing it, what do you recommend? Haven't seen too many 106 LSA's advanced....most have been straight up.
 
To be honest, I'm really not the guy you'd want to ask about that since I'm not into engine building to make a living...there are much more intelligent guys on here than me about that; but if you're running a flat top 360, I'm gonna guess you're up around 10:1 based on a 65cc head, 040" gasket, and zero decked KB 107s. And with that much squeeze, you probably wouldn't have to advance the cam at all. I will state for the record, I don't know jack about your MP heads...

If you dropped compression to around 9:1, then I'd say you could bring it up 2-4*. Regardless, that 106 LSA is gonna chop, and likely be kinda pissed off in the midrange...almost like a circle track cam-should pull hard from a roll.
 
I would leave it straight up. Hughes stuff usually has 3 degrees in it, straight up.

If you really want to try different things, get a timing set with different keyways, or an adjustable gear set. Set at zero, check cyl. pressure and see if you like it. If it's up there, leave it be. If you want to go higher, at that point, do a timing cover gasket and try it out.

I'm always in favor for leaving it where you know it will work and checking results, before moving anything around on a new combination.
 
I'm wondering if this combo will work on pump gas?

MP advertises these heads as 58cc.

To get the piston to deck clearance of those KB's, it goes like this;

Deck height (9.6") - sum of half stroke distance (3.58"/2=1.79") + rod length (6.123") + compression distance (a KB 107 is @ 1.675") which leaves you with .002", which is the distance from the top of the piston to deck. If you've milled the block .002", you have effectively given the engine zero deck on these pistons.

The KB 107 has +5cc for valves.

Add a .040" gasket, which is now all of your quench distance and you get 11.47:1 static comp ratio. In Washington, altitude is 1,706' avg. Your dynamic compression is going to be up there, even at zero on the cam advance.

If I were you, I would be checking everything with a microscope. CC those heads in real life and see exactly what they are, with the plugs in that you plan on using. Check installed height on those pistons with a mic and see what they actually look like.

As stated above, unless you are up in the mid 60's on the heads, this is a lot of comp for a street engine, even with a mild cam.

What are you planning on doing with this engine?
 
Thanks Dave and txstang84. Yes, car is summer/weekend driver only that will never see the track.

I too was worried about my comp ratio with this combo so I've recently decided to make a head change to the RHS X heads (don't trust the casting on these alum heads anyway). FWIW, my elevation is sea level to approx. 600 ft.

The RHS X heads come 62-67cc (your choice) for no extra cost...any advice here what to run?

I started this thread looking for some advice on a new roller cam and rockers and after hearing some of you guys chime in and doing a little more research, here's what the new combo is going to look like.

'67 Notch (3400lbs w/driver)
360 Magnum, .030 over
KB107's, zero'd
288/293 adv, 229/234 @ .050, .502/.513 (w/1.65 rockers), 106 LSA, 78.5 overlap
RHS X heads (2.02/1.60)
PAC beehives, .600 max lift
360 stock crank
Eddy RPM air gap
727 w/3.91 SG
9.5" dynamic converter with 3000 stall
TTI W2 headers
650cfm eddy

Anything look out of whack here guys? Should I advance the cam at all now that I've made a head change?

Thanks again in advance for all your help!
 
I think it could use more cam.
 
Even with a 67cc chamber, and true zero decks, you'll still be over 10:1 CR with an .040"x4.1" head gasket. I think it'll be a snappy performer with the 3k stall and 3.91 gears out back...I think your biggest problem will be keeping tires on it, so make sure your rear is dialed in.

EDIT:
I think it could use more cam.
Click to expand...

...could definitely supply enough compression for more cam.
 
He has enough compression for more cam.
 
I would not install the 106 LSA cam advanced if you want to run pump gas.

See if you can get the chambers up around 70cc
 
more cam for just a weekend street driver? don't get me wrong, i'll get on her from time to time but this car will never see the track. i have no problem camming up if you guys really, really think the rest of the combo and our intended use (street only) calls for it.

i definitely want to stay on pump gas so if i stick with this 106 LSA cam i have now, straight up it is...thanks crackedback!

i'm assuming i can get to 70cc from 67cc just by running a thicker gasket??
 
See if the chamber can be 70, not the right way to go by putting a thicker gasket in, defeats quench.

A wider LSA cam would help you here...
 
yeah, i wanted a 110 LSA but this cam came in my motor (i bought it assembled) and i don't have to spend a nickel if i keep it.

i can have the LSA widened on this cam (Oregon Cam Grinding). Cost is $150 and they said they could get to a 108 for sure, maybe a 110 (wouldn't know until it was on the machine). I really like the chop of this 106, but if it's just not the right angle for what I'm trying to accomplish, I can have it changed.

on a side note, i can get my hands on a brand new crane hyd roller that's 292/300 adv, 230/238 @ .050, .563/.584 (w/1.6 rockers), 112 LSA for a good price if this cam would work better (seems like too much cam to me but...????).
 
so my cam decision has been made and with my new Hughes 1.65 rockers, my lift is gonna end up being .571/.581.

I am I still gonna be okay running my OEM lifters with this amount lift? Heads will be RHS X heads assembled by Brian at IMM that are good to .600.
 
Just a quick plug for Oregon cam. I have a similar build and goals for my 360 Magnum. I went with the 1357 grind after speaking with Ken. Great service! Not saying you should use the same grind but I was super pleased with their service. Regrind was about $130 shipped. I just got it back about a week ago and it looks great. Best of luck with your build.
 
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