Cam Shaft Questions
Thread Starter
Racer
Joined: Jan 2005
Posts: 499
Likes: 0
From: Enfield CT
Cam Shaft Questions
Hello I am running a Low mileage 1980 L82.It has a Trickflow upper engine package.My torque converter is a 2600 to 2800 stall speed.I have a Quick Fuel 650 cfm mechanical secondary carb feeding her.The cam that came with the package is a 210/216 duration @.050 440/454 lift.
The car idles and runs great.Its best track time is a 13.04 1/4 mile.I am now a bit bored with it and wants some more power on the cheap!
Hence the cam questions.Trickflow has another kit with a different cam, 228/234 duration @.050 480/494 lift.It seems like a good choice for my package.I want to reuse all of my stuff and just change the cam.
1.My heads are rated at 480 max lift,so is this cam OK to use?
2.The valve springs on my heads are1.25 and the other kits springs are at 1.47, same spring rate,I don't know if this is a problem?
3.Can I still use my 650 cfm carb if re jetted?
4.How much idle quality and vacuum will be lost?
5.THE BIG QUESTION OF ALL: WILL I SEE AT LEAST 50HP INCREASE AND WHERE IN THE POWER BAND WILL I SEE IT?
6.I was looking at the Trickflow cam because its power band is 2600rpm to 6100rpm.Will I need new lifters also?
7.What about a roller conversion? Thanks in advance
Thanks in advance!!!!!!!!!!!!
The car idles and runs great.Its best track time is a 13.04 1/4 mile.I am now a bit bored with it and wants some more power on the cheap!
Hence the cam questions.Trickflow has another kit with a different cam, 228/234 duration @.050 480/494 lift.It seems like a good choice for my package.I want to reuse all of my stuff and just change the cam.
1.My heads are rated at 480 max lift,so is this cam OK to use?
2.The valve springs on my heads are1.25 and the other kits springs are at 1.47, same spring rate,I don't know if this is a problem?
3.Can I still use my 650 cfm carb if re jetted?
4.How much idle quality and vacuum will be lost?
5.THE BIG QUESTION OF ALL: WILL I SEE AT LEAST 50HP INCREASE AND WHERE IN THE POWER BAND WILL I SEE IT?
6.I was looking at the Trickflow cam because its power band is 2600rpm to 6100rpm.Will I need new lifters also?
7.What about a roller conversion? Thanks in advance
Thanks in advance!!!!!!!!!!!!
Last edited by bozzman3; May 15, 2011 at 08:23 PM.
Burning Brakes
Joined: May 2008
Posts: 860
Likes: 0
From: Stratford Ontario
That cam should work OK with those heads. Not sure on the springs? I like to match my springs to the cam. I would go with a 750 carb.Not sure exactly on vacum but it shouldnt be too bad. No 50 hp increase. You will definately need lifters! The big problem could be, do you have enough compression for that cam. Roller conversion would be nice but opens a whole new can of worms.
Race Director
Joined: May 2005
Posts: 10,674
Likes: 122
From: Millington Illinois
St. Jude Donor '08-'09
You have good heads 195 cc with 62 CC chambers. Should get you close to 10 to 1 comp. The springs limit your lift as those same heads are used on there other top end packages. I would look at over .500 lift and the most duration I could get @ .050 without going over 274 advertised intake duration to keep your DCR up.
This one will get you you 50+ HP but it would like some rear gear. Your convertor will compensate somewhat though. And yes it is a billet roller cam. Get the kit with all components.
http://www.summitracing.com/parts/ISK-201272-282/
This one will get you you 50+ HP but it would like some rear gear. Your convertor will compensate somewhat though. And yes it is a billet roller cam. Get the kit with all components.
http://www.summitracing.com/parts/ISK-201272-282/
Last edited by 63mako; May 15, 2011 at 11:52 PM.
Thread Starter
Racer
Joined: Jan 2005
Posts: 499
Likes: 0
From: Enfield CT
You have good heads 195 cc with 62 CC chambers. Should get you close to 10 to 1 comp. The springs limit your lift as those same heads are used on there other top end packages. I would look at over .500 lift and the most duration I could get @ .050 without going over 274 advertised intake duration to keep your DCR up.
This one will get you you 50+ HP but it would like some rear gear. Your convertor will compensate somewhat though. And yes it is a billet roller cam. Get the kit with all components.
http://www.summitracing.com/parts/ISK-201272-282/
This one will get you you 50+ HP but it would like some rear gear. Your convertor will compensate somewhat though. And yes it is a billet roller cam. Get the kit with all components.
http://www.summitracing.com/parts/ISK-201272-282/
Race Director
Joined: May 2005
Posts: 10,674
Likes: 122
From: Millington Illinois
St. Jude Donor '08-'09
Using the Trickflow cam won't get you 50 HP even though their advertising says so. It will increase your power noticably at higher RPM. Your torque curve will move up. It will not pull as well at the bottom end. That is the tradeoff. The roller cam will give up less bottom end and give you more up top than the flat tappet due to faster ramps and higher lift. It is also going to be more durable. The heads should work fine with either with a spring change. That is what is limiting your lift to .480. As always you need to check piston to valve clearance and valvetrain geometry needs to be set up properly
Thread Starter
Racer
Joined: Jan 2005
Posts: 499
Likes: 0
From: Enfield CT
This was suggested by one of my friends as well.I am liking this idea because its cheap and wont effect my bottom end torque.Can any body tell me about the gains I could enjoy with this swap out?
Cruising
Joined: Apr 2011
Posts: 10
Likes: 0
To add an additional few questions to this. won't this change duration to some extent and does it have any impact on durability in regards to the valve stem and it's contact point to the new rocker....?
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Drifting
Joined: Aug 2005
Posts: 1,682
Likes: 3
From: League City TX
You would also have issues with pushrod clearance where they pass through the head.
As far as total duration, it would remain unchanged.
The valve would spend more time at or above any given lift, but it would still unseat and seat at the same points.
Race Director
Joined: May 2005
Posts: 10,674
Likes: 122
From: Millington Illinois
St. Jude Donor '08-'09
The cam you have is a "fast ramp" cam. The rate at which it and closes the valve is at about the fastest rate it can be done with a flat tappet. Adding the rockers will give you more lift but it increases the "hydraulic intensity" of the cam, loading the lifter, cam contact point substatially more which increases the chance of a wiped cam lobe. The springs were not designed for the additional lift and you would surpass the .480 the springs are rated at which would probably cause spring failure. These fast ramp flat tappet cams make more power than conventional ramps but the tradeoff is reduced valvetrain life. Duribility will be reduced. Do a search on camshaft hydraulic intensity.
Last edited by 63mako; May 18, 2011 at 09:41 AM.
