Lumpiest cam with gt40p setup?

Bigstang1 · Dec 22, 2003

Can anyone who has a gt40p setup post their combos. I want a real lumpy idle but not hurt down low performance too much. I was thinking b-303 with 1.7rr. Please keep the "dont do it for the sound "and the "alphabet cams suck" replies to a minimum. Everyone knows the b303 sounds mean and will the 1.7s keep the torque downlow a little better?

giddyup306 · Dec 22, 2003

It all depends on what sort of compression you are runnuing.

Bigstang1 · Dec 22, 2003

Whats a reasonable compression to run with these heads n/a and stock bottom end that is freshened up with new bearings rings oil pump and timing chain? If i just bolt them on without milling, what compression will i come out with?

giddyup306 · Dec 22, 2003

Bigstang1 said:
Whats a reasonable compression to run with these heads n/a and stock bottom end that is freshened up with new bearings rings oil pump and timing chain? If i just bolt them on without milling, what compression will i come out with?

If I remember correctly the GT40 heads are 60cc which would put ya around 9.2:1. You might be able to run a cam with 110* LSA with that compression (where you get your thumper).

strtracer442 · Dec 22, 2003

That cam is designed for a 5speed car, youll need a torque converter or its gonna dog down low

Michael Yount · Dec 22, 2003

"I want a real lumpy idle but not hurt down low performance too much"

Wanting both of those things is kind of like wanting to be a musician when you grow up. You can't do both.

crazydave · Dec 22, 2003

Lumpy ?

Michael Yount said:
"I want a real lumpy idle but not hurt down low performance too much"

Wanting both of those things is kind of like wanting to be a musician when you grow up. You can't do both.

I have p heads and an E cam with 1.7 rockers. It is fairly lumpy and yes you do loose a little down low. I put a D 1 procharger on and now no one can tell my lack of low end problems. The supercharger took a bit of the lump out of the idle also. However the loud whine of the D1 combined with a little lummpy cam is one of the meanest things I have ever heard.

Bigstang1 · Dec 22, 2003

Well as far as it being a 5speed cam, I am doing a 5speed swap at the same time Im doing the engine work so there isnt a problem there.

It will only come out to 9.2:1 cr? I was hoping for a lil higher. Can i mill the heads to run say around 10:1 with no piston to valve clearance inssues with the b303 and 1.7's? Will i be able to run on 93 or 94 pump gas? Sorry alot of questions but i want to do this right.

Bigstang1 · Dec 22, 2003

tomst9 · Dec 22, 2003

sorry to ask this during you post but can someone explain to me what exactly lobe separation angle means. And whats the benefit of 110 or 112 or 114.
thanks
tom

Michael Yount · Dec 22, 2003

Hey Tom - Lobe separation angle is the number of crankshaft degrees between the centerline of the intake lobe and centerline of the exhaust lobe. It is ground into the cam, and can't be altered unless you pick a cam with a different LSA. Generally speaking, the LSA is simply a result of the designer's selection of valve event timing, although many people focus on it as an important specification of the camshaft. If you really want to understand more about how cams do what they do, go here and read all the tabs. http://www.wighat.com/fcr3/

mustangdaren · Dec 22, 2003

I am running a B303 cam, 1.6 rr with the regular gt40 heads. It is plenty lopey. With a 3.73 gear it has plenty of torque down low. Way more than regular radials can take. I probably wouldn't have chosen this cam if it hadn't come in the motor I bought but I am plenty happy with it. I would have went with a comp cam or a lunati. I heard one of the trick flow cams and they sound pretty mean also. Here is a sound clip of mine, it's not the greatest recording but will give you an idea of what it will sound like.

http://mustangdaren.web.aplus.net/sitebuildercontent/sitebuilderfiles/dynomaxbullet2.mp3

Bigstang1 · Dec 23, 2003

ttt

That sounds pretty mean daren. Its a real rough idle but not a whole lot of lope. Is that a supercharger i hear in the backround or is it a gear drive?

mustangdaren · Dec 23, 2003

Bigstang1 said:
ttt

That sounds pretty mean daren. Its a real rough idle but not a whole lot of lope. Is that a supercharger i hear in the backround or is it a gear drive?

It's a vortech sc-trim. The car has more of a lope when it is idling lower. That was a 1100 rpm idle. I got to install an IAC adjustment plate and tweek the TPS to get it to idle lower. Since I installed the blower the idle went all to crap.

giddyup306 · Dec 23, 2003

Bigstang1 said:
Well as far as it being a 5speed cam, I am doing a 5speed swap at the same time Im doing the engine work so there isnt a problem there.

It will only come out to 9.2:1 cr? I was hoping for a lil higher. Can i mill the heads to run say around 10:1 with no piston to valve clearance inssues with the b303 and 1.7's? Will i be able to run on 93 or 94 pump gas? Sorry alot of questions but i want to do this right.

Yep 9.2:1 with the stock bottom end and 60cc heads. You could mill the heads .020 and get around 9.5:1 BUT I personally wouldn't do it. If you ever have to shave off a little because the heads are warped you might not be able to true the heads up because you would be out of specs. If anything try and get the heads O-ringed. You will gain a little compression there and it will seal better but that costs $$. BTW I think you can only mill the GT heads .040 and still be within specs. Yes if you go 10:1 you should be fine with 94 octaine. Just don't go too far on the timing.

Bigstang1 · Dec 23, 2003

Lots of info there giddyup thanks. If i shouldnt mill the heads to get around 10:1 with gt40ps, how can i get it that high? Different pistons? Thanks

stanglx · Dec 24, 2003

Bigstang1 said:
Lots of info there giddyup thanks. If i shouldnt mill the heads to get around 10:1 with gt40ps, how can i get it that high? Different pistons? Thanks

Yes there are some pistons out there that will give you more compression. There are some stock replacement pistons that stick out of the block a little that I hear work pretty well. The wrist pin has a different placement that allows the piston to stick out a bit. I believe Speed Pro makes some. I think you have room to mil the P's a little. Stock they can be anywhere between 60 - 63cc's. You might want to have them checked and than decide if you want to take some off.

I have my P's milled to 58cc's. I'm using a stock cam and 1.7rr's. My machinest figured that I am at about 10.1:1.

Bigstang1 · Dec 25, 2003

Stanglx, are you usuing these special stock replacment pistons or no? Ur setup sounds like what i want to do with the exception of the stock cam. Id like to use a b303 or a tfstage1 . Will i still maintain the 10:1 with the bcam or tfs1? How much did a shop charge u to mill the heads? I am on a super budget so if i can get away with the stock bottom end thats the way i want to go, but i am def looking for around 10:1 compression with a nice sounding cam for an all around good performing and good sounding street car. Notice i put good performing first lol I would also be interested in hearing a soundclip of stanglx's car. 10.1 with stock cam must sound interesting. Thanks and Merry Christmas

Bigstang1 · Dec 25, 2003

Mean88 · Dec 26, 2003

I am running gt40p heads, with speed pro pistons. My compression is around 9.7 with the heads unmilled. I believe the heads are 63cc. The speed pro kit I have is for a 10:1 compression with 58cc heads I believe. I am running speed density still, but I have a crower #511 cam with 1.7's. The Idle is lumpy, and the car has torque up the a$$! I thought with the addition of a camshaft of any kind that I would lose major bottom end, but it seems alot stronger than it was stock. The powerband of this cam is awesome-1800-6000rpm. The cam idles at 850, smooth as a baby's a$$- no surging.
Ted

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