My Crane cam lift numbers

[jeepinwi]

I took the time to check the amount of lift for my Crane cam. It's a Crane 753905 and has been run in my stroker for 17,300 miles. I broke in the engine with Rotella T oil and have run an SL rated oil since then. I've always had a rough idle and had a CEL for a "cylinder 6 misfire". The good news is that none of my lifters were collapsed...all had preload.

Here's how I checked the amount of lift:

I know it's not perfect, but It's a very close measurement. I measured each pushrod with the rocker arm loose and at maximum compression. I found the difference and multiplied by 1.6. The actual amount of lift is slightly lower since the pushrods are closer to the rocker arm pivots. Here's my results from front to back:
INTAKE: 1-.395:
2-.416"
3-..422"
4-.422"
5-.451"
6-.458"
EXHAUST: 1-.414"
2-.418"
3-.467"
4-.472"
5-.428"
6-.483"
The cam had .456/.484" valve lift when new. I was hoping these numbers would help explain my CEL, but I'm more confused now. I expected cylinder 6 to have the most wear. Apparently the cylinder 6 lobes are in the best condition. I guess these numbers just confirm that Crane cams really are pieces of junk . The next cam I'm going to try is an Isky 133125. It has a straight .450" lift, and is very similar in specs to the Mopar P4529230 Cam.

 

[j99xj]

If I were you I'd go back to a stock cam but with roller rockers.

 

[jeepinwi]

I know the stock cam is the most reliable choice, but I didn't build a stroker to get mediocre power. I'm also not going to pony up $300+ for roller rockers when my valvetrain is dead silent now. I haven't heard of anybody running an Isky cam, so I'll be the guinea pig for us.

 

[Flash]

I took the time to check the amount of lift for my Crane cam. It's a Crane 753905 and has been run in my stroker for 17,300 miles. I broke in the engine with Rotella T oil and have run an SL rated oil since then. I've always had a rough idle and had a CEL for a "cylinder 6 misfire". The good news is that none of my lifters were collapsed...all had preload.

Here's how I checked the amount of lift:

I know it's not perfect, but It's a very close measurement. I measured each pushrod with the rocker arm loose and at maximum compression. I found the difference and multiplied by 1.6. The actual amount of lift is slightly lower since the pushrods are closer to the rocker arm pivots. Here's my results from front to back:
INTAKE: 1-.395:
2-.416"
3-..422"
4-.422"
5-.451"
6-.458"
EXHAUST: 1-.414"
2-.418"
3-.467"
4-.472"
5-.428"
6-.483"
The cam had .456/.484" valve lift when new. I was hoping these numbers would help explain my CEL, but I'm more confused now. I expected cylinder 6 to have the most wear. Apparently the cylinder 6 lobes are in the best condition. I guess these numbers just confirm that Crane cams really are pieces of junk . The next cam I'm going to try is an Isky 133125. It has a straight .450" lift, and is very similar in specs to the Mopar P4529230 Cam.

Is it possible that the stamped steel rocker are not the same hight on the edge there.

I think scribe the pushrod at no lift and at full lift (Without the rocker arm on) would be more accurate.

Flash.

 

[alex22]

Hydrolic lifters can be causing the discrepencys. If i remember correctly the oil is fed from the back of the engine so the #6 lifters would be the first to recieve oil. You could take an old lifter and fill it with loctite and after leting it sit for atleast a day itl be a solid lifter.

~Alex

 

[Flash]

Hydrolic lifters can be causing the discrepencys. If i remember correctly the oil is fed from the back of the engine so the #6 lifters would be the first to recieve oil. You could take an old lifter and fill it with loctite and after leting it sit for atleast a day itl be a solid lifter.

~Alex

:jester:
The only problem with that, is that the head would have to be removed to remove the lifter.


flash.

 

[jeepinwi]

Flash-
It wouldn't matter if the rocker arms are the same height. I simply used them as a point to measure from. I measured them at their highest point(springs completely compressed), and at their lowest point(rocker arm loose). I think Alex may be onto something about oil being fed from the rear of the engine. Can anybody verify this? In the morning, I may try scribing the pushrods for a more accurate measurement.

 

[gradon]

I wanna hear about your results with the Isky. I'm half a step away from trying to get the Mopar P4529230 Cam. I'm also wondering how the 1.7 YTs would complement that cam.

 

[alex22]

:jester:
The only problem with that, is that the head would have to be removed to remove the lifter.


flash.

Ahhh yes, minor details.

:idea:

Another idea. This is a bit complicated and you will need a dial indicator, a magnetic base and a length of rod (1/8 to 1/4), a drill and tap for the threads in the indicator. Since the walls of the lifter are solid all the way to the top you could use the rod to make a long extention for the indicator and actually touch the side of the lifter. The only potential problem i can see with this method would be size and placement of the pushrod holes. you might need to do some trig to find the actual lift if you have to put the indicator at an angle.
The other problem is that not everybody has a magnetic base dial indicator and a drill and tap set for some tiny thread. The other option for the indicator extention is to just weld a longer pice of rod to the tip that comes with it.

~Alex

 

[CJR]

jeepinwi,

I just went through this on my 88XJ 4.0L. I rebuilt it with the same Crane cam you used and it ran fine initially and then the performance started to fall off. I pulled the engine at 10,000 miles, on the rebuild, and three or four lobes were worn. I talked to Crane about it and they replaced it and the Crane lifters. However, as others have found, the Crane lobe widths are 0.500 inch and the OEM lobe widths are 0.6649 inch. AMC made wide cam lobes for a good reason. So instead of installing the replacement Crane cam, I had Comp Cams regrind my OEM cam and I am very happy with it.

Best regards,

CJR

 

[seanyb505]

jeepinwi,
I had Comp Cams regrind my OEM cam and I am very happy with it.

How much did this cost and how much power do you think it gained as a result?
thanks

 

[JTwthaXJ]

This might be hi-jacking the thread, but can I ask how much did it cost to have Comp regrind your cam... I am kind of like you in the idea of building a stroker, I want one with more than mediocre power. I have built one before but it used the '91-'92 HO cam which was 270/270 I believe. My '97 is a little milder, I am aiming for the 270/270 with mine and if it takes regrinding a stock cam, then no problem... I was following the yahoo strokers group to get a hydraulic cam made, but the total cost would have been somewhere in the range of $2K for the entire valve train. I don't think that the regrind of a stock cam would be that much...

thanks

 

[MudDawg]

To get accurate gross lift, you need to pull the rockers and pushrods and read directly from the lifter....long probe on a dial indicator....and compare to manufacturer's lobe spec.

The narrow lobe profile I don't particularily like, it puts the edge of the lobe closer to the lifter centerline...the closer it is the harder it is to get the lifter to properly spin in the bore (very much required). I have heard reports of wear associated with lifter base wear from lach of lifter rotation that has been alternately blamed on excessive lubricity or lack of proper additive packages....bottom line....I think wider is better...or course remember the lobe is ground with built in camber...the lifter is not actually flat...together the lobe lifter interface rides on the edge of the lobe to generate the required rotation....having said that...the stock HO cam does quite well...but here's a cam name I havent seen thrown out that I used to use extensively in SBC engines with great reliability.....Erson.....and they do make a couple of grinds to fit the ole 4.0.

 

[streetpirate]

big x2 for erson, they also make my favorite profile, e710321.

 

[CJR]

Seanyb505,

It cost me a $100 to have Comp regrind my OEM cam. That price includes a thorough inspection and measurement of all the lobes by Comp Cams. Then Comp contacts you and tells you what regrinds can be done to your cam based on its condition. Then you tell Comp what regrind you want and they start the job. It doesn't take long and you've got the regrind back. Excellent turn around time!

The power band for the Crane cam I had was 1500-4500 rpm, the power band for the Comp cam is 800-4200 rpm. So when I started to accelerate with the Crane cam there would be a slight lack of power (i.e. 600-1500 rpm) until I got to 1500 rpm then it would come on strong. With the Comp cam, as I start to accelerate it only takes me 200 rpms (i.e. 600-800 rpm) before I'm in the power band and pulling strong with lot's of low-end torque. Likewise, for slow crawling I'm already operating in the power band generating max torque with the Comp cam.

Overall, I'm very pleased with the Comp cam. I used to use Crane cams exclusively in all my engine rebuilds but now I like Comp cams. I ran a lot of comparsions between the Crane and Comp cams with my Performance Trends software. As a result of those comparsions, I'm satisfied that I'm getting the highest average torque in the power band I want with the Comp cam.

Best regards,

CJR

 

[alex22]

For my build, I am going to use a Camcraft custom grind for a low to mid power band. My grind will depend on how the head flows and the valve train. I have not contacted them yet but my boss said he has done a few 4.0 cams for us in the past and atleast 100 cams for other engines.
He has a very good discription of why flat tappet cams are failing on his website, a coppy of this is in the shop's entry way.

~Alex

 

[Flash]

For my build, I am going to use a Camcraft custom grind for a low to mid power band. My grind will depend on how the head flows and the valve train. I have not contacted them yet but my boss said he has done a few 4.0 cams for us in the past and atleast 100 cams for other engines.
He has a very good discription of why flat tappet cams are failing on his website, a coppy of this is in the shop's entry way.

~Alex

now, your not going to leave us hanging like that are you :hang: ?

How about takeing a pic............even better, a link :thumbup:

Flash.

 

[5-90]

We've bashed around the problem with "modern" "Energy Saving" oils before - it's the lack of organometallics (Hell Flash - you've seen it gone into here and at Strokers, no?)

You can get a dial indicator, a set of extensions, and a magnetic base fairly cheap if you know where to look - start with Enco or MSC Direct (both have house brands that are adequate for the measurement involved, and the extensions are already threaded #4-40 for use with the dial indicator.) A 0-1" travel will suffice for just about any camshaft.

As long as you're turning the engine by hand, you can just indicate off of the backside of the rocker arm. Lifter pumping is really only an issue when there is oil pressure - which you don't get with the "socket on the screw" method you're using. While it won't get you numbers accurate enough for camshaft analysis or checking grind profile - for which you should remove the cam and have it on the bench anyhow - it will get you what you need to know, and is effective for comparing one lobe to another. Leave everything bolted up, and use the backside of the socket that the pushrod fits into on the rocker arm for your reading point.

Again, while this isn't a terribly analytical method, it will get you useful results to within about three thousandths (I've checked.) Turn the engine over slowly, and I'd suggest you turn it a couple times before you start taking measurements to get the lifters settled.

As for oils - do not buy oils billed as "energy saving." Flip the bottle over and make sure it still has a Diesel rating (should be "Sx/Cy" - "S" for "Spark Ignition" and "C" for "Compression Ignition,) as Diesels haven't caught on to the roller camshaft kick yet, and still need the organometallic anti-scuff additives used for flat tappets. Or, stock up on General Motors' Engine Oil Supplement (EOS) to add with each oil change.

I've been using Valvoline, Castrol, and Chevron engine oils with good results - again, make sure it has a Diesel rating! Don't bother with the oils that have the "Energy Saving" sunburst logo on the front, as that doesn't have what we need for flat tappets and cams!

Even accounting for wear, those lift numbers seem awfully scattered. It may be instructive to invest a few bucks in a dial indicator and a mag base and recheck - either off the back of the rocker, or off the tappet itself (if you set it up right, the angle should be almost negligible, but it would have to be measured accurately if you're going to account for it...)

 

[Flash]

We've bashed around the problem with "modern" "Energy Saving" oils before - it's the lack of organometallics (Hell Flash - you've seen it gone into here and at Strokers, no?) YUP BUT I'M ALLWAY INTERESTED IN YET ANOTHER CAM COMPANYS APPIOION

You can get a dial indicator, a set of extensions, and a magnetic base fairly cheap if you know where to look - start with Enco or MSC Direct (both have house brands that are adequate for the measurement involved, and the extensions are already threaded #4-40 for use with the dial indicator.) A 0-1" travel will suffice for just about any camshaft.

As long as you're turning the engine by hand, you can just indicate off of the backside of the rocker arm. Lifter pumping is really only an issue when there is oil pressure - which you don't get with the "socket on the screw" method you're using. While it won't get you numbers accurate enough for camshaft analysis or checking grind profile - for which you should remove the cam and have it on the bench anyhow - it will get you what you need to know, and is effective for comparing one lobe to another. Leave everything bolted up, and use the backside of the socket that the pushrod fits into on the rocker arm for your reading point.

Again, while this isn't a terribly analytical method, it will get you useful results to within about three thousandths (I've checked.) Turn the engine over slowly, and I'd suggest you turn it a couple times before you start taking measurements to get the lifters settled.

As for oils - do not buy oils billed as "energy saving." Flip the bottle over and make sure it still has a Diesel rating (should be "Sx/Cy" - "S" for "Spark Ignition" and "C" for "Compression Ignition,) as Diesels haven't caught on to the roller camshaft kick yet, and still need the organometallic anti-scuff additives used for flat tappets. Or, stock up on General Motors' Engine Oil Supplement (EOS) to add with each oil change.
I WISH I COULD!:rattle: .....GOT PULL OF THE SHELF ALLMOST 2 MOUTHS AGO............SUPOSIDLY IT GOING TO BE RE RELEASED AS GM PERFORMCE PRODUCE LINE.................BUT IT HASN'T YET AND I NEED TO GET THIS 15/40 OUT OF MY JEEP........ITS JUST TO THICK NOW.
IF THAY WOULD RELEASE EOS AGAIN I COULD RUN 5W30 COMPFERTABLLY

I've been using Valvoline, Castrol, and Chevron engine oils with good results - again, make sure it has a Diesel rating! Don't bother with the oils that have the "Energy Saving" sunburst logo on the front, as that doesn't have what we need for flat tappets and cams!

Even accounting for wear, those lift numbers seem awfully scattered. It may be instructive to invest a few bucks in a dial indicator and a mag base and recheck - either off the back of the rocker, or off the tappet itself (if you set it up right, the angle should be almost negligible, but it would have to be measured accurately if you're going to account for it...)

 

[alex22]

Here is CamCraft's main site. http://camcraftcams.com/index2.html in the side menu there is one called "Cam Failures" where he gives his opinions and his recomended break in procedures.
As for engine oil. I plan on using one of Brad Penn's oil, it is rated for street use with flat tappet cams. I am going to buy a few quarts (need to look in the book) and a filter tomorow. My price for it is $5 a quart. I have also heard that Joe Gibbs has a flat tappet cam oil intended for street use comeing out soon.

If I remember correctly a magnetic base dial indicator is about 20+ shipping from MSC, not sure about the attachment kit.

~Alex