ok guys, this is what i have..
385ci stroker
about 10:1 comp ratio
cam: 306º int/exh 260º @.050" .592" int .555" exh 110º LSA
brodix racerite 200 heads 67cc
victor jr. intake
mighty demon 750 annular


i want to raise the compression from 10:1 to about 10.3:1... i will mill the heads to about 63.7cc.. i was just wondering how much power i will gain from this?? i am at a 12.41@110.. and i am trying for 11's.. how close will this get me??

 

hmmm I believe it was something like 3 percent for every full point ? like going from 10:0 to 11:0 ???

 

anyone else???

 

No noticeable difference for that small of a compression change.
I think you have a typo in your cam specs as well.

 

comp cams
solid flat tappet
306 advertised
260 int 260 exh @.050
.592" int(1.6 rocker) .555 exh (1.5 rocker)
110 LSA

what could i do to lower my ET?? i'm not gonna spray, dont have the budjet to supercharge, turbo is definetly out of the question.. a cam change possibly?? roller?? i already know i can knock off at least .10 on the 60ft.. my best so far is 1.81 spinning a little.. on MT ET radials.. i will switch to ET streets as soon as they wear out..

 

Try a carb spacer and some under drive pulleys.

 

Maybe this engine would do it!

http://cgi.ebay.com/ebaymotors/NEW-3...43707316QQrdZ1

 

work on getting your chassis to work better. an anti roll bar works wonders on 3rd gens. get your 60ft down to the 1.4's 1.5s and you will pick up in the 8th and the 1/4. i would have gone with a different cam myself, somthing with a 106 or 108 lobe center, 110 lobe center is more of a street cam.

 

On another note I'm wondering if that cam is a good match for the heads. Seems like a very large cam for 200cc heads.

 

i have a 1" carb spacer and i cant use underdrive pulleys because the motor likes to heat up and at idle, the alternator makes just enough juice to run the motor itself..


haha if i had the money, i wouldnt be in this situation.. i would have had a 434 sbc by now, putting me well into the 10's..


i have an antiroll bar on the rear, its a 1" suspension techniques piece with energy suspension bushings.. i'm gonna try get some blownout rear shocks and eventually some 90/10's for the front.. also i'm looking into getting some LCA relocation brackets.. would they help?? also about the cam lobe center, wouldnt 108 and 106 lobe centers require more compression?? another thing is that this is a street car.. i drive this once in a while.. it is also a 5-spd..


yes, this cam is rather large.. its made for 10.5:1 comp and up.. i thought i had the comp but after i got a some times down, i was dissapointed and i calculated the comp ratio to around 10:1.. i didnt realize that i wasnt zero decked until i found the invoices for the machining.. any suggestions as to a cam selection?? i'm running a solid flat right now and would like to keep it that way..

 

What is your deck height, and what gasket?

You can always go to a thin gasket, and shave the heads as well. That might bring you into the high 10's. Angle mill if needed, you'd have to mill the intake as well, or the intake mating surface on the heads. Maybe clean up the ports on the heads with a die grinder. You should be able to knock off the casting flash without having a PHD in cylinder head porting.

YES! LCA relocation brackets are a damn good idea! The 9" currie only has a single bolt hole location ? Are the LCA's parallel to the ground normally?
What about the torque arm? (if still using that setup?) adjustable for pinion angle?

 

sonix, i believe i have a stock deck height and my rotating assembly is 9.000".. so i'm guessing i have about .025" deck height.. i use a felpro head gasket.. i think its .041".. will milling the heads and changing the gasket really give me that much more compression?? and i could port the heads, as i do have the carbide bits and what not.. i ported the victor jr. to fit the heads.. the currie does have only one bolt hole.. and the LCA's are just about parallel to the ground.. i have a spohn torque arm that i'm gonna try and hook up straight to my chassis.. it is adjustable.. i have the one that bolts to the tranny.. i do get a little wheel hop from the bushing and the trans mount.. i couldnt get the crossmember mount one cause i had my true duals before i bought it..

 

If you can remove the TA mount from the tranny, that'll help wheel hop most. Look into LCA relocation brackets after the TA mount issue.

Well, keep in mind, the following info is based on your #'s. If you're confident that is your deck height, etc, then this info will be correct. If it's wrong, then garbage in -> garbage out right? ok:

Using this calc;
http://kb-silvolite.com/calc.php?action=comp

I'm seeing a 4.040 bore 350, with 3.75" stroke, .041" gasket, 5cc flat top pistons, 67cc heads. That shows a 10.1:1 CR.
Just going to a .015 gasket will bring your quench to a tight .040" (nice and tight, the way I like it ). That'll keep detonation away. That alone is worth .6, going up to 10.7:1. If you mill the heads down to 64cc (only 3cc's, that's not a lot), you can jump to 11:1. That'll improve your low end more than anything. The top end will be nicer though.

That's a big cam, so I don't think you'll need race gas for this.

Well, your call on carbide bits on the heads. I figured if they're $$race rite$$ heads, I wouldn't want anything that I could screw up on it. Personally i'd just use a few sanding drum rolls, and work the bowls, short turn, and contour the guide a tad. Don't touch the combustion chambers (or only a TINY bit), since you don't want to drop CR.

 

thanks sonix,
i'm thinking about going with the .015" gasket and maybe shaving the heads down for flatness.. because that is a small gasket.. i'll probably shave the heads down to 66cc and use the .015" gasket.. its gonna be at 10.9:1.. that should be good enough.. if i need to, i can always shave more.. thanks again for the help.. oh and how much power do you think its gonna be worth?? from 10.12:1 to 10.91:1? or to 11.16:1??

 

hey sorry to but in.... but you never talked about your tires, tranny or rear end... or if this is a street car or a drag car... like im thinking get some good seize slicks and a higher stall tc.. dunno if you already have that.. but i thought i would mention it.. and what rear end do you got.. i dunno, im a jr. when it comes to racing.. but i thought it was worth a mention.. maybe try going to a demon 850 cfm.. that would give you better power to..maybe...if it would work... dunno not much about carbs..

 

It'll still only be around 5% or so. But in your range, that's about 20 HP. I think since you were below the spec'd range for your cam, it'll probably help more across the RPM range, the 5% is just at the top end. Net overall change will probably be more. It'll effect driveability too (pure drag strip or street time as well?)

Heads, cam, intake and carb are pretty well matched. Pulling a 12.41 is alright, but I think that combo might be able to net you a bit better. Look for a weak link somewhere else as well.
(I mean, sheesh, when Matt can pull those times in a 305 with a smaller cam and cheesier heads, then you should be able to blow it away)

 

Dave, the car is more of a street car than a strip.. but i dont drive it everyday because in hawaii the gas is about $3.50 a gallon for 92oct.. i usually drive it a couple times a week and on the weekends.. i have 275/50-15 MT ET street radials.. thats 26".. i got a currie 9" with 3.89 gears, a g-force t-5, and an 850 would most likely be too much carb.. i've seen in mag articles where they use an 850 for "big-inch" small blocks.. like 427s and up.. keep in mind, i dont have a whole lot of compression..

Sonix, i hear you about Matt and his 305.. i was hoping this setup would put me to at least 11.6's.. but i guess not.. as i said above, the car is more of a street car.. but i dont really care about driveability.. as long as it can go from here to there and back, then i'm fine.. anyway, my suspension setup is a bit of a weak link.. i mean honestly, i have a best 60 ft. of 1.81.. and thats on a 5k dump.. i am getting a 2-step because i usually dont have time to preload before the lights go.. i'm also gonna get a set of MT ET streets.. the slick looking ones, not the radials.. i have the radials and spin them..

 

hey sonix, you said that because of the big cam, i probably wont need race gas.. do you think i could get away with 11.2:1 on 92 octane?? or maybe just an octane booster?? the combustion chambers on my heads are cc matched and polished smooth.. and i have the sand drum rolls along with the carbides.. so i may polish out the runners on the intake.. i already ported and polished the victor jr. a little..

 

At 0' altitude? hmm dicey. Use the intake closing angle and find out your dynamic compression ratio, that's the main factor. If that's low enough (due to a ginormous cam), then it might work. I'd make sure to polish the chambers like crazy(already done eh?), that'll drop the CC size a bit. 11:1 is pushing it, even with a cam that big. I'm thinking shoot for 8.5:1 DCR, that's about as high as you want to be on pump gas. Using octane booster is a waste of time, and annoying as heck.

I forget, were these AL or iron heads?

 

ok sonix, i'm not too sure about the altitude but its anywhere from 10-30'.. very close to sealevel.. i am running aluminum heads and i did polish the chambers.. now about this intake closing angle.. how do i go about finding this?? because i have absolutely no idea..

 

5678TA,
With a 1.8 60' time sounds like you would be better off spending money on your suspension first. You could knock a couple of tenths off your 60' time alone. A set of moroso trick springs and 90/10 drag struts would dramatically improve your 60' time. I've also heard that the MT drag radials don't work well with manual trans cars so it might be worth while switching tires too.
But if you do want to change your engine combination I would have the heads fully ported and possibly milled for more compression depending on what you do with the cam. If you swap cams go to a solid roller, the extra expense is worth it in my opinion. Check out the combination in my signature. Its very streetable and runs very low 11's on pump gas.

 

jbenge,
the MT radials do not hook well with a manual.. i could use a better suspension as well.. i have stock springs all the way around, monroe sensatrak struts, and napa shocks.. what rate springs do you have?? also what tire would you recommend?? ET Streets?? i will most definetely port and polish the heads as well as mill them.. how high of a compression do you think i could go?? the highest i "could" get is 11.2:1.. i would like to stay with the cam i have now because there is only about 400 miles on it.. i listed the specs at the beginning of this post..

 

if you can find the cam card (on the website, or in your garage or wherever), it'll list the intake closing angle. It's a cam in the neighborhood of jbenges, (250*/260* ) so i'm thinking it'll bleed off the same amount of cylinder pressure. jbenge runs iron heads (right?) and 11:1. So i'm thinking with your AL heads you should be ok to do that.
AL heads, big cam, 11:1 should be ok.

 

this is what i got off the website.. the compression calculator you linked requires:
Intake Closing Point (degrees) ABDC @ 0.050 lift plus 15 degrees

the specs below only have the .015.. if i put in that number, it comes out to 7.795:1 dynamic.. so, not too sure what number to use.. and jbenge has aluminum heads.. but if you're not too sure about how high i can go, i'll just try it.. if i need to lower the comp ratio, there are bigger head gaskets..



Valve Timing At 0.015
Open Close
Intake 47 79
Exhaust 87 39

These Specs Are For The Cam Installed At 106 Intake CL

Intake Exhaust
Duration At 0.05 260 260
Lobe Lift 0.37 0.37
Lobe Separation 110

 

My heads are aluminum. My cam specs aren't too far from yours, you actually have slightly more duration. You should be able to run pump gas with 11.2:1 compression with the cam you currently have. The springs I'm running are Moroso trick springs 220lbs/in part# 47210. I would go with MT ET streets for tires, I've had good luck with them..some people prefer Hoosiers its a personal preference. Manual cars tend to shock the drivetrain more so I think the bias ply tires having being less stiff would definately help you.