Cam not compatible with overdrive? - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Engine
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 08-04-2010, 08:47 PM
1983 Z28
 
Last photo:
Join Date: Apr 2010
Location: Lima, Ohio
Posts: 80
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Cam not compatible with overdrive?

Still deep into my build, uncovering new problems every step of the way.

The car is a 1983 Camaro Z28 with 3.42 rear gears, and a built 700R4 with a 2400 RPM stall converter. The engine is a 4 bolt 350 with worked Vortec heads, 9.5:1 CR, Weiand Stealth dual plane intake, and a Holley 670 Street Avenger.

This is the cam I chose to use:
http://cgi.ebay.com/ebaymotors/SBC-C...Q5fAccessories

Now, it seemed to be the most aggressive cam I could run in my 350 without having driveability issues, and it appeared to fit my purposes perfectly.

However, I personally spoke with Skip White about my build and he says the cam will cause the car to buck and surge in OD, and even worse with lockup engaged. He said if I had maybe 4.10 gears with small tires I might be able to get away with it, otherwise I would need a larger motor (383) with a higher CR to make it work. I'm inclined to believe him due to the operating range of the cam (2500-6500). Before I took the car apart I held 2400 at 70MPH.

Am I going to regret installing this cam? If so, can anyone recommend a cam that will net me the same power (looking for a minimum of 375hp at the crank), while playing well with the low RPM's my 700R4 inflicts? I love the sound the Crane 1064 makes, and I already purchased so I would prefer to use it if possible, but if there's a good chance it's going to give me trouble, I don't want it.

I really don't want to step down in cam size per Skip's suggestion.

Help!
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 08-04-2010, 09:22 PM
Registered User
 
Last photo:
Join Date: Nov 2003
Location: oklahoma
Age: 32
Posts: 250
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
It sounds like you know what needs to be done. It isn't hard to get 375hp out a 350 with vortec heads. You said your heads are worked what kind of max lift are they good for. Most are only good for .47 or .48 lift. You can get them to take more but this is the most common.

Is this going to be a daily drive or more of weekend toy. I would look more into a com in the 270-280 range Compcams magnum series.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 08-04-2010, 10:36 PM
DoubleVision's Avatar
Not Considered a Senior Member
 
Last photo:
Join Date: Oct 2002
Location: Heart Of Dixie
Age: 40
Posts: 10,643
Wiki Edits: 0

Thanks: 13
Thanked 56 Times in 53 Posts
I see this mistake often and I tell those that make it to get out there calculator before the cam pick to make sure everythings going to work.
What I mean is you have to add up with your rear end ratio and OD ratio and see what the cruise RPM is going to be. Lets say at a cruise speed of 55, your in OD, the engine is spinning a estimated 1800 RPM. Now compare that to what RPM the cam`s power band starts at, if the cam`s powerband is say 2500 to 6500, then 1800 RPM cruise is 700 RPM too low, which will cause the symptoms you describe. This is why I say do your homework before hand, as it will save you a lot of grief later. When I`m doing a build like yours with a OD transmission I add it all up and find out what I`m going to have to have. I like for the cams power band to be at least 200 RPM lower than the cruise RPM. The limiting factor in this is you may have to run a considerably smaller cam than you perferred and if you have to have the original cam you picked out then the next job will be changing the rear gears to a lower ratio. In some cases you can crutch things and advance the cam 4 degrees and lower the powerband by 200 RPM but this is only if its borderline close. So your next move will either be a smaller cam or lower gears. You can go to this site I`ll point out and do all the calculating you need.
http://www.gmhpclub.com/performancecalculators.htm
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 08-04-2010, 11:38 PM
techinspector1's Avatar
Senior Curmudgeon
 
Last wiki edit: DynoSim combinations Last photo:
Join Date: Oct 2005
Location: Hemet, California, USA
Age: 72
Posts: 12,192
Wiki Edits: 326

Thanks: 590
Thanked 755 Times in 645 Posts
Junior, you're trying to have your cake and eat it too with your mismatched mumbo jumbo of parts. Make a decision. Do you want to rip the tires off or do you want to cruise with overdrive and make mileage?
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 08-04-2010, 11:45 PM
F-BIRD'88's Avatar
Yada Yada Yada
 
Last photo:
Join Date: Oct 2005
Location: Ontario, Canada
Posts: 9,181
Wiki Edits: 0

Thanks: 2
Thanked 292 Times in 289 Posts
The cam you are looking at wants a 4.10 (short tire) or 4.56 (tall tire) and a 3500-4000 stall converter. Needs 10:1.

Not a good choice for 3.42's and a 2400 stall.

Not going to work at all with a OD trans.

Crane makes similar, shorter duration cams in this series that are more suitable
to your car.
www.cranecams.com

BlueRacer cams:

214-224-.442-.465-112 This cam will make 375hp in a vortec 350.
Just right for your mild converter and 3.42's

224-234-.465-.488 114 more top end do not go bigger than this one.

Crane HMV series: 272-284 216-228-.454-.480-112 another good one.

278-294-.467-.494-114 This one makes 405 hp in a vortec 350. (HMV278-2)

Modified hi-lift vortecs can benefit using a 1.6 rocker on the intake side on all these cams.

Again unless you are going to change the converter and gears the cam you have not the best. The bottom end below 3000rpm is soggy. needs rpm compression, gears and converter to work.

This cam is the "GoLdIe LocKs" cam for your car 1.6 in 1.5 ex rockers.

Last edited by F-BIRD'88; 08-05-2010 at 12:09 AM.
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 08-05-2010, 07:16 AM
Custom10's Avatar
my KARMA ran over my DOGMA
 

Last journal entry: SS
Last photo:
Join Date: May 2009
Location: Saskatchewan, Canada
Age: 49
Posts: 1,067
Wiki Edits: 0

Thanks: 10
Thanked 21 Times in 19 Posts
Ask skip if he still has any blue racer WP-3 cams left, I bought one off him early this year and it is the one Fbird refers too at 214-224 442-465.
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 08-05-2010, 09:40 AM
Overdriv's Avatar
Member
 
Last photo:
Join Date: May 2005
Location: IL
Age: 63
Posts: 740
Wiki Edits: 0

Thanks: 0
Thanked 2 Times in 2 Posts
Just for your information, I have a 406 SBC with a Comp Cams XE274 cam, 700R4, 4.56 gears, 31" tires.

I can run between 55-60 MPH in OD locked up, at about 2100RPM. The truck will run smooth and get 16 MPG with AC on. It will run down to about 1900 RPM but is on the verge of "bucking and jumping" I believe was the terms.

I brought my timing in as soon as possible, all in by 2800 RPM and I run all the vacuum advance I can. It will step right out at 2100 and you can really feel the cam and timing come in as it speeds up.

I'm not sure how your cam compares to mine as I'm at work and Ebay is a no-no.

Keep the good sounding cam and run a deeper gear, it's more fun.

Hope this helps.
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 08-05-2010, 10:35 AM
1983 Z28
 
Last photo:
Join Date: Apr 2010
Location: Lima, Ohio
Posts: 80
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
I've already matched the heads to this cam, I'm around .520-.530 max lift on them.

For the record, this is my nice daily driver, not a project car, weekend toy, or track car. However, my goal is to have a well streetable car that I can run at the track a few weekends a year, then jump on the interstate and drive home. I feel dumb, but up until now OD is the only thing I didn't take into account when choosing the cam. I knew I was a little low on the stall speed as well as the CR, but I figured I would make it work.

Fuel mileage isn't my biggest concern. With my old cam and heads I could pull 22mpg at 75mph, but anything between 15 and 20mpg in OD with lockup engaged, I'll be happy with.

Rear gears aren't going to get changed unless I break something. I love my 3.42's, the car was always hot off the line and cruises really well with a 26" tall tire, even back when it had the 305.

The torque converter is a B&M Tork Master with a 2300-2500RPM stall. It's what B&M recommends for a medium weight car with 350-450tq. Remember this isn't an all out drag car, I don't need to get every ounce of performance out of the cam.

The cam doesn't have to be a Crane, I would actually prefer to go with Lunati or Comp this time around unless someone can recommend the perfect cam. I would much rather squeeze the setup for all I can as I would rather be closer to the 400hp mark than 375.

Also keep in mind, I don't need to use lock up or overdrive around town, so the lowest RPM's I'll see are maybe 2000 at 55MPH. If I'm cruising any slower than that I can disengage lock up or take it out of OD.

Here's what I'm considering:

Comp Cams Magnum 270H: .470 lift, 270 advertised duration, 1800-5800 operating range

Comp Cams XE268H: .477/.480 lift, 268/280 advertised duration, 1600-5800 operating range

Comp Cams XE274H: .490 lift, 274/286 advertised duration, 1800-6000 operating range

Lunati 60102: .468/.489 lift, 262/268 duration, 1400-5800 operating range

All have a 110 LSA, except for the Lunati which has a 112 LSA. All of them are largest cam for stock converter/gears or require slightly higher stall than stock according to Comp and Lunati. I'm actually leaning towards the Lunati or the XE268.

Any opinions?
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 08-05-2010, 10:57 AM
DoubleVision's Avatar
Not Considered a Senior Member
 
Last photo:
Join Date: Oct 2002
Location: Heart Of Dixie
Age: 40
Posts: 10,643
Wiki Edits: 0

Thanks: 13
Thanked 56 Times in 53 Posts
Not to worry about the mistake Jr. We`ve all been there.
When putting together a project so many things come to mind there`s not enough room to remember everything.
Anyways, Usually I would have picked the Comp magnum cam as I perfer a single pattern design, but in this case, you`ve did your homework, either the
XE268 or the Lunati would work fine. If it were I, I`d use the comp cam.
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 08-05-2010, 11:04 AM
1983 Z28
 
Last photo:
Join Date: Apr 2010
Location: Lima, Ohio
Posts: 80
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
I actually just found another 3rd generation F body with a very similar setup as me.

350, Vortec heads, XE268 cam, 9.2:1 CR, 700R4, 3.42 rear gears, dual plane intake, headers, and 3" exhaust.

On the dyno he put down 260hp and 280 ft/lbs of torque, and his best 1/4 mile time is 13.5 with a trap speed of 102mph on street tires.
http://www.youtube.com/watch?v=LlcrS...eature=related

When a 20% drive train loss is taken into account, he's making about 325hp and 350tq.

I was REALLY hoping to put down 300RWHP, and break into the high 12's with drag radials. I thought my original goal was realistic, but it seems a little out of reach now without doing a 383 or raising my CR.
Reply With Quote Quick reply to this message
  #11 (permalink)  
Old 08-05-2010, 11:05 AM
F-BIRD'88's Avatar
Yada Yada Yada
 
Last photo:
Join Date: Oct 2005
Location: Ontario, Canada
Posts: 9,181
Wiki Edits: 0

Thanks: 2
Thanked 292 Times in 289 Posts
It seems you are only looking for someone to agree with and validate your choice(s).

For a near stock converter, mild gear, and OD keep the cam small.

big cams need compression, gears, converter and RPM.
No amout of "I can make this work" will change that.

I have built and ran the identical combo car and engine gear trans converter you have.
The Crane HMV 272-2 cam with 1.6-1.5 rockers is the one you want.
Get a entry level 150hp nitrous kit and some ET streets for the track and hang on.
Reply With Quote Quick reply to this message
  #12 (permalink)  
Old 08-05-2010, 11:09 AM
F-BIRD'88's Avatar
Yada Yada Yada
 
Last photo:
Join Date: Oct 2005
Location: Ontario, Canada
Posts: 9,181
Wiki Edits: 0

Thanks: 2
Thanked 292 Times in 289 Posts
Quote:
Originally Posted by Jr. Mechanic
I actually just found another 3rd generation F body with a very similar setup as me.

350, Vortec heads, XE268 cam, 9.2:1 CR, 700R4, 3.42 rear gears, dual plane intake, headers, and 3" exhaust.

On the dyno he put down 260hp and 280 ft/lbs of torque, and his best 1/4 mile time is 13.5 with a trap speed of 102mph on street tires.

When a 20% drive train loss is taken into account, he's making about 325hp and 350tq.

I was REALLY hoping to put down 300RWHP, and break into the high 12's with drag radials. I thought my original goal was realistic, but it seems a little out of reach now without doing a 383 or raising my CR.
The car did not perform cause the cam is too big.

I ran same exact combo with a crane/blueracer 214-224-.442-.465-112 13.00 flat @105.

Thats 375 gross dyno HP 300 to the wheels.

Bigger cams require higher 10:1+ cr 4.10's-4.56 and 3500-3800 stall to realise the top end gain.

got the T-shirt on this one.
The carb is too small and will hold the combo back. get a 750cfm carb if you want power.

The most common error people make is selecting the wrong (too big) cam for the combo and intended overall purpose.
The second is using too small a carb.
You seem hell bent to make both classic/common mistakes.

Last edited by F-BIRD'88; 08-05-2010 at 11:21 AM.
Reply With Quote Quick reply to this message
  #13 (permalink)  
Old 08-05-2010, 11:16 AM
1983 Z28
 
Last photo:
Join Date: Apr 2010
Location: Lima, Ohio
Posts: 80
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by F-BIRD'88
It seems you are only looking for someone to agree with and validate your choice(s).

For a near stock converter, mild gear, and OD keep the cam small.

big cams need compression, gears, converter and RPM.
No amout of "I can make this work" will change that.

I have built and ran the identical combo car and engine gear trans converter you have.
The Crane HMV 272-2 cam with 1.6-1.5 rockers is the one you want.
Get a entry level 150hp nitrous kit and some ET streets for the track and hang on.
Not looking for validation, I'm looking for opinions from guys who have been there, such as yourself. Obviously you're right, I couldn't make the 1064 work, which is why I'm here asking.

I don't really like any other cam Crane has to offer for my setup. The one you mentioned is more mild than the ones I have listed, and has an operating range too close to my lock up RPM's for my liking.

On top of performance, I really want a racy, quick revving sound, so too mild isn't going to work.
Reply With Quote Quick reply to this message
  #14 (permalink)  
Old 08-05-2010, 11:26 AM
F-BIRD'88's Avatar
Yada Yada Yada
 
Last photo:
Join Date: Oct 2005
Location: Ontario, Canada
Posts: 9,181
Wiki Edits: 0

Thanks: 2
Thanked 292 Times in 289 Posts
Quote:
Originally Posted by Jr. Mechanic
Not looking for validation, I'm looking for opinions from guys who have been there, such as yourself. Obviously you're right, I couldn't make the 1064 work, which is why I'm here asking.

I don't really like any other cam Crane has to offer for my setup. The one you mentioned is more mild than the ones I have listed, and has an operating range too close to my lock up RPM's for my liking.

On top of performance, I really want a racy, quick revving sound, so too mild isn't going to work.
use Isky cam cam #201271 270 Mega cam
This is the biggest cam I'd use in this car without a gear/converter change.
Verify the installed position. Recurve the distributor. It has the idle you are looking for.
www.iskycams.com look it up. can use 1.6 rockers.

Last edited by F-BIRD'88; 08-05-2010 at 11:38 AM.
Reply With Quote Quick reply to this message
  #15 (permalink)  
Old 08-05-2010, 11:27 AM
Overdriv's Avatar
Member
 
Last photo:
Join Date: May 2005
Location: IL
Age: 63
Posts: 740
Wiki Edits: 0

Thanks: 0
Thanked 2 Times in 2 Posts
With your current projected specs, at 2000 RPM in OD locked, you will be going 64 MPH. That would be pretty good if your state has a 65 MPH speed limit, you could run 70 with out a strain. But at 55 MPH your combination will be at 1700 RPM. Do you think that will be usable?

These guys aren't trying to rain on your parade, you really do need either a smaller cam to dial that torque band way down, or just run a deeper gear. Just because you love your 3.42 gears now doesn't mean you will always be in love with them. You've made some big change decisions, and when you went to the OD trans, which I think is a smart move for the street now a days, that is a big game changer. Slow down, back up a little, do your math, and you will have a very fun street machine.
Reply With Quote Quick reply to this message

Recent Engine posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Cam button length/clearance..? mrdreex Engine 1 04-12-2008 10:17 PM
Cam Selection and Dynamic CR Arcuden Engine 10 03-23-2008 11:03 AM
I need cam help 355s10 Engine 7 03-16-2008 05:34 PM
Help Me Pick A Cam Canadian Charlie Engine 2 11-16-2005 01:11 PM
another cam ouestion...ie...cam timing VETTE GUY Engine 0 06-28-2003 11:29 AM


All times are GMT -6. The time now is 08:06 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.