Cam not compatible with overdrive? - Page 2 - 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
  #16 (permalink)  
Old 08-05-2010, 01:30 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
Quote:
Originally Posted by Overdriv
It appears you are not considering the .7 ratio of the 700R4 and the lockup converter. Stall speed means nothing when you are lockup. If you want all that to be usable you might want to think about some changes.
Could you elaborate please? I don't plan on running the TC locked at WOT, the only time the TC will be locked is on the interstate at 65-75 MPH.

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #17 (permalink)  
Old 08-05-2010, 01:53 PM
Member
 
Last photo:
Join Date: Aug 2010
Location: Missouri
Posts: 466
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
an AF gauge will tell you NOTHING about properly sizing a carb. Quick rule of thumb is to take hpX2. in other words your typical 350hp chevy will work with a 700cfm carb. The smaller the carb the easier it will be tune at low RPM though.

And you're thinking of your gearing all wrong. you're 3,42's are more like 2.73's when comparing it to the normal hot rod crowd is is running a th350 or something similar.

If you want a hot cam then get hot cam gears and a hot cam converter. 4.10's minimum and a 3,000 stall, as already stated several times.
Reply With Quote Quick reply to this message
  #18 (permalink)  
Old 08-05-2010, 01:56 PM
Overdriv's Avatar
Member
 
Last photo:
Join Date: May 2005
Location: IL
Age: 64
Posts: 740
Wiki Edits: 0

Thanks: 0
Thanked 2 Times in 2 Posts
Understood. The converter lockup means about 200 RPM off the engine. That combined with the .7 ratio of the 700R4 in OD will determine your cruise RPM. Reread my other comments.

Being young doesn't make you stupid, it might mean you lack a bit of experience. But understand when you ask questions and share specs for others to consider, you will get their opinions and suggestions.

Quote:
Originally Posted by Jr. Mechanic
Could you elaborate please? I don't plan on running the TC locked at WOT, the only time the TC will be locked is on the interstate at 65-75 MPH.
Reply With Quote Quick reply to this message
  #19 (permalink)  
Old 08-05-2010, 03:22 PM
V8 Super Beetle's Avatar
VW makes it, Chevy shakes it..
 
Last photo:
Join Date: Jan 2008
Location: Houston, TX
Age: 33
Posts: 1,245
Wiki Edits: 0

Thanks: 5
Thanked 0 Times in 0 Posts
I'd go for the 270 Isky cam F-Bird suggested. I think you'll be happy with it. Popcorn machine idle, great midrange performance, and you'll be pretty close to the 400 marker.

I'd also possibly consider this Howards Max Torque camshaft.

220/220 @ .050, 284/284, .470/.470, 108 lsa. 1,700-5,700.
http://www.summitracing.com/parts/HRS-110991/
Reply With Quote Quick reply to this message
  #20 (permalink)  
Old 08-05-2010, 04:07 PM
Registered User
 
Last photo:
Join Date: Apr 2007
Location: Seattle, Wa
Posts: 7,095
Wiki Edits: 0

Thanks: 4
Thanked 541 Times in 457 Posts
Quote:
Originally Posted by Jr. Mechanic
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?
If I were you, I'd move to Texas. There isn't anything in your choice of components that's going to end up with a year around daily driver in Ohio that won't be downright miserable, if not impossible, for at least half the year. Or at least put a stick gear box in the thing so when it chokes up on icy air and unburnable fuel you can kick the clutch in to free up the crank then tinker with the throttle position to clean it out and get it running again for a few minutes.

Your selection of parts will make a great summer runner. You've among other things, hit the great hot rodder's/racer's conundrum that "what's good for the track, isn't good on the street", at least if you don't live in a place with a warm year around climate.

Your choices for parts would be great if you lived in LA, DFW, Houston, St Pete but for Cleveland, Chicago, Indy, etc. this just won't make a year around hot rod commuter car that's much fun, if not dangerous.

Bogie
Reply With Quote Quick reply to this message
  #21 (permalink)  
Old 08-05-2010, 04:28 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
Quote:
Originally Posted by oldbogie
If I were you, I'd move to Texas. There isn't anything in your choice of components that's going to end up with a year around daily driver in Ohio that won't be downright miserable, if not impossible, for at least half the year. Or at least put a stick gear box in the thing so when it chokes up on icy air and unburnable fuel you can kick the clutch in to free up the crank then tinker with the throttle position to clean it out and get it running again for a few minutes.

Your selection of parts will make a great summer runner. You've among other things, hit the great hot rodder's/racer's conundrum that "what's good for the track, isn't good on the street", at least if you don't live in a place with a warm year around climate.

Your choices for parts would be great if you lived in LA, DFW, Houston, St Pete but for Cleveland, Chicago, Indy, etc. this just won't make a year around hot rod commuter car that's much fun, if not dangerous.

Bogie
No sir, not worried about that. She gets driven up until early November when the lowest temperatures are in the 30's-40's. It's a warm weather DD, not to mention she's never seen snow. Although I did drive it right up until the first snow this last winter and she always fired right up with the choke set. I have a Jeep that gets driven in the winter and in bad weather.
Reply With Quote Quick reply to this message
  #22 (permalink)  
Old 08-05-2010, 04:47 PM
Hippie's Avatar
Analog man in a digital world.
 

Last journal entry: HEI comparison.
Last photo:
Join Date: May 2003
Posts: 2,253
Wiki Edits: 0

Thanks: 3
Thanked 5 Times in 5 Posts
When I was your age I turned my daily driver GTO into what you're looking for. By the next fall I had purchased a cheap beater car to drive back and forth to work. I did end up driving it year round but it wasn't near as much fun as I let on.

If you can't give up having to have the choppy idle and want to be able to cruise in OD then you better plan on sticking more gear in it. I'd put something on the order of a 4.56 in it, that gives you a FDR of 3.19 to 1 with the 700R4. Cruise RPM @ 55 with a tire having a true loaded rolling diameter of 25" will be about 2360. Here's a link to calculate tire loaded diameters....

Gear Ratio and Tire Dia. Calculators

You've been given some great advice from guys that have "been there done that" and have already made the same mistakes. None of us think you're dumb but you sure are stubborn.
Reply With Quote Quick reply to this message
  #23 (permalink)  
Old 08-05-2010, 07:19 PM
Registered User
 
Last photo:
Join Date: May 2008
Location: ohio
Posts: 1,613
Wiki Edits: 0

Thanks: 54
Thanked 67 Times in 64 Posts
Well I guess I will throw my 2 cents in here. First of all you don't want to over cam your engine. Yes we all love that lopey sound at idle but it does you no good if you plain on driving this thing every day. I went with to big of a cam in a couple several builds in the past and I had to learn the hard way and lose out on lots of money.

I am running a 350 sbc, crane 284/292 222/230 @50 with 509/527 lift, 9 to 1 compression, edelbrock rpm dual plane intake, world 2 sportsman heads, turbo 350 transmission with a 2200 rpm stall with 3.42 rear end gears.

I had this motor built last summer to put into my 96 chevy s10 and this is my truck I drive everyday back and forth to work and I had done everything to tune this thing and have various things over the last couple of months to get this thing to run efficient and have come to the conclusion that my cam is a little too big for everyday driving in my opinion for my setup.

Yes I like the lopey idle and I have plenty of vacuum with 15 inches but keeping the plugs clean and keeping the carburetor working really good and trying to get excellent street manners with stop and go traffic stops everyday has taken its toll on me. You can't have your cake and eat it too as the old expression goes. I would go with a smaller cam as to what was suggested by the guys who posted here.

In a couple of weeks I am going to a 260/270 212/218 @ 50 510/510 lift roller cam to replace the bigger crane cam in my motor. Yes I will lose some power on the very top end but I will have way much better torque and response on the bottom end and midrange where my rpms are the most. I cruise at 2200 rpm at 55 and my motor is decent wise but its still at the bottom end of the power band and it is kind of soggy with my current stall.

With this being your everyday ride you want something that will cruise around all day long and be withing a good rpm range for what you got. I did a bigger to smaller cam swap in my more decked out ride that I only drive on the occasion too cause of too many headaches and having over camed my engine.

You can do what you want but if you want to be honest with your self like I had to do then you will have to try to make the best decision on what will be best for your vehicle overall and what will make it run the best with what you have. I love the big racy cams but I won't ever go that radical of a route in any future builds ever again.

That type of setup requires a lot more maintenance over the long haul and is more and more in my experience not worth it just for the ultimate power and sound. I just want to have something nice and still be able to drive it around Good luck on your build I am sure you will make a good choice hopefully.

Eric
Reply With Quote Quick reply to this message
  #24 (permalink)  
Old 08-05-2010, 07:20 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
Well right now I'm leaning towards the XE274H. Seems to be the most aggressive cam I can run. Comp calls for a 2200+ stall converter, and says the operating range starts at 1800 RPM.

Thoughts?
Reply With Quote Quick reply to this message
  #25 (permalink)  
Old 08-05-2010, 07:37 PM
hemi joe's Avatar
loves ex cop cars
 
Last photo:
Join Date: Apr 2009
Location: west deptford nj
Age: 53
Posts: 366
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
this post has totally blown my mind on overdrive.i have a 700R4 in my caprice.if you don't put car in overdrive,how do you have a problem what cam is installed.please don't beat me up but i don't understand,i thought a 700R4 was great for a big cam????????????i do understand about torque converter,but the rest makes no sence.
Reply With Quote Quick reply to this message
  #26 (permalink)  
Old 08-06-2010, 07:26 AM
Overdriv's Avatar
Member
 
Last photo:
Join Date: May 2005
Location: IL
Age: 64
Posts: 740
Wiki Edits: 0

Thanks: 0
Thanked 2 Times in 2 Posts
Quote:
Originally Posted by hemi joe
this post has totally blown my mind on overdrive.i have a 700R4 in my caprice.if you don't put car in overdrive,how do you have a problem what cam is installed.please don't beat me up but i don't understand,i thought a 700R4 was great for a big cam????????????i do understand about torque converter,but the rest makes no sence.
I think the point is, why overdrive if you don't plan for it and use it. If you aren't going to use OD, there are probably better choices for a trans, like the THM400. Just my opinion of course.
Reply With Quote Quick reply to this message
  #27 (permalink)  
Old 08-06-2010, 07:51 AM
cobalt327's Avatar
WFO
 
Last wiki edit: Intake manifold
Last journal entry: 1980 Malibu Wagon
Last photo:
Join Date: Mar 2009
Location: Atlanta
Age: 60
Posts: 5,037
Wiki Edits: 1616

Thanks: 128
Thanked 598 Times in 547 Posts
Quote:
Originally Posted by hemi joe
this post has totally blown my mind on overdrive.i have a 700R4 in my caprice.if you don't put car in overdrive,how do you have a problem what cam is installed.please don't beat me up but i don't understand,i thought a 700R4 was great for a big cam????????????i do understand about torque converter,but the rest makes no sence.
It just goes to show, that there's no "free lunch".

HJ, because of the relatively big drop in RPM that OD gives, this brings the engine down in RPM so low, that the engine doesn't make enough horsepower/torque (with a 'big' cam) to allow the vehicle to smoothly drive down the highway.

So, there's a limit on things. Big cam = more rear gear. But then first gear (w/its 3.06:1 ratio) becomes a ~14:1 ratio joke when using the necessary 4.56:1 rear gear that's needed to get the OD RPM up to a place where the engine's making some real power.

Obviously, if OD isn't used, and the trans is used like a 3-speed AT, well, there's not so much of a 'problem', other than the added expense of the OD trans that isn't utilized, and the cost to bullet-proof it to begin with. But in that case, I agree w/Overdriv that there are better trannys to start w/from the beginning.
Reply With Quote Quick reply to this message
  #28 (permalink)  
Old 08-06-2010, 04:36 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
Okay guys, I've done A LOT of research on the XE274H and found numerous people running it with Vortec heads and overdrive. From my research, I've gathered that around 230 duration @.050 is where you start sacrificing driveability.

The XE274 has 230/236 duration @.050. The .490 lift should work out nicely with my valve train.

Apparently, Vortec heads seem to thrive on this cam, making 400+ hp at the crank.

Car Craft built a stock Vortec 350 with some head work and an XE274 cam and made 442hp and 452 ft/lbs of torque.

With the operating range coming it at 1800 RPM's, I haven't been able to find one person having trouble with this cam and overdrive, no matter the gearing.

I also decided I'm going to get a Summit Racing 2600 stall converter. I figure it will be a good balance for street and strip.

Speak now or forever hold your peace!
Reply With Quote Quick reply to this message
  #29 (permalink)  
Old 08-06-2010, 04:41 PM
Registered User
 
Last photo:
Join Date: May 2008
Location: ohio
Posts: 1,613
Wiki Edits: 0

Thanks: 54
Thanked 67 Times in 64 Posts
Well if it was my build with that setup I would go with the comp cam xe 256 h or at the very least the next one up at the most. I have the same rear end ratio as you do but I don't have overdrive like your 700r4 and I only have a 222/230 @ 50 cam and mine is barley acceptable going down the highway with a 2200 stall for my experience as to why I am putting in a smaller cam to give me better bottom end and midrange with out taking too much off the top.

I bet once I am done will have a nice night and day difference with street manners and performance and I will be much happier with how it will run. Bottom line it's up to you on what you want. That cam is still a little on the bigger side for street ability wise with good manners. My cam does not pick up till about 2500 rpm and it does not like it in town when the rpms are below 2000 most of the time. 1800 rpm is bare minimum and its best to be a little above the rpm band for bettor results.

My smaller cam will start to go at 1500 rpm and I am always above that going through town and mine will even work with a stock stall converter and with my 2200 rpm stall I should really wake up my bottom end some. Have fun I am sure you will get something worked out. At least your asking and taking advice to heart. Some just roll with it and don't care how it runs.
Eric
Reply With Quote Quick reply to this message
  #30 (permalink)  
Old 08-06-2010, 04:42 PM
techinspector1's Avatar
Senior Curmudgeon
 
Last wiki edit: DynoSim combinations Last photo:
Join Date: Oct 2005
Location: Hemet, California, USA
Age: 72
Posts: 13,327
Wiki Edits: 326

Thanks: 843
Thanked 1,157 Times in 955 Posts
Do what you want to Junior, you're going to anyway.
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:
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 11:17 PM
Cam Selection and Dynamic CR Arcuden Engine 8 03-23-2008 12:03 PM
I need cam help 355s10 Engine 5 03-16-2008 06:34 PM
Help Me Pick A Cam Canadian Charlie Engine 2 11-16-2005 02:11 PM
another cam ouestion...ie...cam timing VETTE GUY Engine 0 06-28-2003 12:29 PM


All times are GMT -6. The time now is 06:23 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.