Can too much cam hurt the car...?

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Highbredcloud

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Mar 4, 2003

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Palos Hills, IL

Oct 18, 2004

#1

• Oct 18, 2004

• #1

well can too much cam hurt the car especially in high RPM's? Here is the setup in question...

CNC ported GT-40 cast iron heads...(possibly stock valves not sure)(1.84/1.54) exhaust side if fully ported to 1415 felpro...intake side is opend up to 1250 felpro
Ported GT-40 lower intake
TrickFlow stage II cam

224 intake/232 exhaust
.339 in./.352 in. cam lift
.542 in./.563 in. lift
112 LSA

along with rest of the bolt ons...

This cam already came with the motor...is it even possible to run such big cam in a 302/306(possibly)? Would the cam have to be retarded for it not to have piston to valve clearance issues? If your retard the cam the power band comes in sooner but the motor won't rev as high...where as if you advance the cam the powerband is moved up higher and the motor can rev more right? I get those two confused...

Here is what is happening...the car starts to make power around 2500 RPM according to the stock tach...and stops pulling at 5100RPM...The car is VERY torquey between 2500 and 4500RPM...I am running 24# injectors...not sure if the car has a bigger fuel pump...no fuel pressure regulator...could I be running out of fuel up top or is the cam hurting me...? any suggestion on what else could it be? My timing is set at 14*...can iron heads take 16* without detonation...? is that too much too little? I have NO detonation at 14*...is this too much cam for my setup?

 

R

raph130

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Oct 18, 2004

#2

• Oct 18, 2004

• #2

*

 

N8Miller

I need NOS....make it 2 of the big ones

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Oct 18, 2004

#3

• Oct 18, 2004

• #3

raph130 said:

you can't hurt an engine with a cam. too much timing can hurt it due to pinging and detonation even with premium gas.

Click to expand...

what?

depends on your meaning of hurt. if it will hurt performance to overcam a car... yes, it can hurt it.

also, wouldnt running a big cam increase the risk of colliding pistons and valves????

also, that cam is pretty decent. it should make power up to 6k or more. You should ATLEAST make power to 5500. those heads a good.. underrated by a few.

 

TrickStang37

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Oct 17, 2004

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Oct 19, 2004

#4

• Oct 19, 2004

• #4

definetely change the fuel pump. I used to run 15* on my stock heads on 91 oct with no pinging/detonation issues at all.

 

H

Highbredcloud

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Mar 4, 2003

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Palos Hills, IL

Oct 24, 2004

#5

• Oct 24, 2004

• #5

anyone else can help me out with this...reason I am so concerned is that this is a really big cam...would a smaller cam work better with the setup mentioned above? bigger isn't always better right? Help me out here guys...

 

N8Miller

I need NOS....make it 2 of the big ones

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Oct 24, 2004

#6

• Oct 24, 2004

• #6

I know a guy at the track who runs an X303 cam (bigger than what you have-----or about the same... i forget #s), heads and intake on a 306 set up. he runs low 13s all day.

too big..... nah.

 

J

jd351

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Everett, WA

Oct 24, 2004

#7

• Oct 24, 2004

• #7

Yes, you can over-cam a motor and/or car. The cam needs to be right for the airflow potential and car weight/gears. BUT, the cam your speaking of is not all that big for what you have. A little big, but not so much as to cause serious power loss. Any power lost by this cam should be down low. This cam should alow full potential of the heads and intake up high. I would start to look for another cause. How about fuel supply, ignition problems, or exhaust? Is there something else not up to par, like too small a T/B or MAF meter?

BTW, I hope your running 3.73 or greater gears with that combo too.

 

GroverDill

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Oct 24, 2004

#8

• Oct 24, 2004

• #8

I am no cam expert but, thats a lot of cam for a pretty mild set up.

 

H

Highbredcloud

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Mar 4, 2003

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Palos Hills, IL

Oct 25, 2004

#9

• Oct 25, 2004

• #9

N8Miller said:

I know a guy at the track who runs an X303 cam (bigger than what you have-----or about the same... i forget #s), heads and intake on a 306 set up. he runs low 13s all day.

too big..... nah.

Click to expand...

The X cam is as follows:

224*/224*
.542/.542 lift...

not sure about the LSA...the TFS stage II is definately bigger especially on the exhuaust...

TFS stage II

224 intake/232 exhaust
.339 in./.352 in. cam lift
.542 in./.563 in. lift
112 LSA

 

H

Highbredcloud

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Palos Hills, IL

Oct 25, 2004

#10

• Oct 25, 2004

• #10

jd351 said:

Yes, you can over-cam a motor and/or car. The cam needs to be right for the airflow potential and car weight/gears. BUT, the cam your speaking of is not all that big for what you have. A little big, but not so much as to cause serious power loss. Any power lost by this cam should be down low. This cam should alow full potential of the heads and intake up high. I would start to look for another cause. How about fuel supply, ignition problems, or exhaust? Is there something else not up to par, like too small a T/B or MAF meter?

BTW, I hope your running 3.73 or greater gears with that combo too.

Click to expand...

The car does have 3.73 gears...A Pro-M 77mm MAF and currently a 70mm BBK/Eddelbrock TB...which I will be replacing with a Ford Racing 65mm one...The BBK/Eddelbrock sticks all the time plus I think I will gain more with the smaller TB...I have 24# injectors...I believe a stock fuel pump...I will be replacing it with a 255lph one as soon as I get a day off...I will aslo be getting rid of the stock fuel pressure regulator and putting a Kirban...what psi should I run with the 24# injectors? stock? more? The ignition is stock...

The problems is the car has low end...it's just the top end that sux...which makes no sesne...it may be running out of fuel up top...cuz the car seems to stop pulling at 5100 RPM...by stock tach...the car starts to pull at 2500 and feels really torque to about 4500 RPM...than falls flat on its face at 5100 RPM...why?

Currently I have hooker shortie equal lenght headers...total crap along with a total crap mac off road X-pipe...will be replacing it with long tube headers and a better x-pipe...

I seriously doubt the heads are over done as well...they are big but I've seen bigger...I really don't know whats up with the car...

 

H

Highbredcloud

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Palos Hills, IL

Oct 25, 2004

#11

• Oct 25, 2004

• #11

GroverDill said:

I am no cam expert but, thats a lot of cam for a pretty mild set up.

Click to expand...

Grover...That's what I'm thinking as well...the only thing that makes me wonder is how much bigger are the heads now after they have been ported...stock the intake volume is 160cc...and 65cc on exhaust...the heads are pretty hogged out...the lower GT-40 intake has also been ported...don't know how much those flow but its got to be in the 220 cfm range if I had to guess...

 

J

jd351

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Oct 25, 2004

#12

• Oct 25, 2004

• #12

Well so far the fuel system would look to be a problem. Up the pump and get the adjustable FPR on, but don't expect this is the whole problem. FP should likely be near stock given the 24LB and a good 255 pump. Might check your TPS voltage a WOT, make sure it's not doing sometning weird like dropping voltage.

Outside of this I guess the cam could be installed far from strait up and causing problems, or the MAF could be prematurly peaking (indicating max airflow) and sending the EEC for a loop, but I doubt it given it is only a 24LB unit and airflow should not be that huge.

 

B

Biggeley

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Mar 4, 2003

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Oct 25, 2004

#13

• Oct 25, 2004

• #13

.

 

B

Biggeley

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Oct 25, 2004

#14

• Oct 25, 2004

• #14

Have enough valve spring to run that cam? You need a fairly stout spring that supports a good amount of lift to use that cam. Lack of adequate valve spring will certainly cause your to loose power in the higher rpm's..

 

maverick0716

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Oct 25, 2004

#15

• Oct 25, 2004

• #15

Way too much cam for a 220 cfm flowing head. If you put a Stage 1 cam in there it would match the combo WAY better!

 

1

1Slow5oh

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Oct 25, 2004

#16

• Oct 25, 2004

• #16

To me it dosent sound like to much cam. If its pulling down low and not up high couldent it be fuel pressure?
IMO when you have to much cam you dont have much in the lower revs and alot up top? right?

 

H

Highbredcloud

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Mar 4, 2003

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Palos Hills, IL

Oct 25, 2004

#17

• Oct 25, 2004

• #17

maverick0716 said:

Way too much cam for a 220 cfm flowing head. If you put a Stage 1 cam in there it would match the combo WAY better!

Click to expand...

220 cfm is just my guess...stock the GT-40 head flows around 190cfm...and these were ported...the exhaust I really have no idea but stock supposedly is 130 cfm so somewhere in 150-160cfm...THe car pulls down low its just the top end that sux...anything after 5100 RPM is horrible...plenty of TQ down low...you can feel the cam pulling at 2000 RPM...

 

dastang2

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Dec 11, 2003

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tx

Oct 25, 2004

#18

• Oct 25, 2004

• #18

that fuel pump has got to be your problem, did you have your valve springs changed to match, you don't want to float your valves or even drop one.

 

O

onefastlx

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Sep 9, 2004

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Oct 25, 2004

#19

• Oct 25, 2004

• #19

I agree with some of the other bros on the fuel pump,get that changed like yesterday!! and I would def check your valves springs....valve float will also hurt top end power and if your valves meet your pistons?? well I think I need to comment on that but you will need a good set of springs to run that cam.

 

H

Highbredcloud

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Palos Hills, IL

Oct 25, 2004

#20

• Oct 25, 2004

• #20

The springs look to be aftermarket and not stock...not sure about the pressure but its a double spring...The fuel pump will be put on this week-end...hopefully that is the problem...