Comp XE295HL cam and spring combination

[91r/t]

I have a 500" stroker using the Comp XE295HL cam and am curious if I have enough valve spring to control this high lift and duration cam. I have Edelbrock RPM performer heads which I belive have the standard springs with whatever they come with. Here are the cam specs and spring specs. Whats the concensus on what I am running? I want to make sure I have enough spring pressure to hold this cam. I am somewhat knowledgeable of this stuff but I like to have some of you better than me advise. Thanks!

 

[lewtot184]

i'd use the recommended comp 924 spring. just because edelbrock says their spring will "take" .600 " lift doesn't mean it will work with that cam. the 924 is designed to take the lift and should work well with those heads. also, keep in mind that an adjustable rocker will more likely than not be a higher ratio than advertised which will increase lift at the valve.

 

[91r/t]

Yea It is a done engine in the car so I was hoping it would work for a driver. I don't race the car or run it to a high RPM range. I just didn't want to have a detrimental issue if they were way off that's all. I fully understand what your getting at Lewtot184. I was also looking for some info on maybe spring pressure needed??? Does that sound correct?

 

[PRND21]

Along with what Lew said, the XE series cams have an extremely fast valve opening and closing rates that are pretty hard on generic or fits all type valve springs.

 

[91r/t]

Along with what Lew said, the XE series cams have an extremely fast valve opening and closing rates that are pretty hard on generic or fits all type valve springs.

That's exactly what I have heard. That is why I was kinda wondering the spring rates needed for that cam and then compare to what was installed on the RPM heads. Figured someone who was *** deep in cam info could give me a good idea whether or not that spring was worth a **** for that fast of a ramp on this cam and its lobes. Down the road, I would like to go with a roller cam setup. I was hoping I could get by with this stuff for a couple summers while I get the parts and funding in order to change cams, but I didn't wanna fubar something if it was that bad of a combo.

 

[not so famous bob]

That's exactly what I have heard. That is why I was kinda wondering the spring rates needed for that cam and then compare to what was installed on the RPM heads. Figured someone who was *** deep in cam info could give me a good idea whether or not that spring was worth a **** for that fast of a ramp on this cam and its lobes. Down the road, I would like to go with a roller cam setup. I was hoping I could get by with this stuff for a couple summers while I get the parts and funding in order to change cams, but I didn't wanna fubar something if it was that bad of a combo.

when in doubt, call the people that made the cam,

 

[lewtot184]

i just checked a new edelbrock spring and with the safe .060" between the coils I get 1.31". this would be .570" maximum safe lift with a 1.88" installed height. adjustable rockers should up the anti some, maybe as much as .600" at the valve. I tried to find more info on the 924's but couldn't find exactly what I was looking for. pretty sure the 924 uses a smaller diameter wire along with an inner spring to help with the higher lifts. the 924 doesn't have a high spring rate which is good for the cam. in my opinion your very much on the edge with the edelbrock spring.

 

[lewtot184]

That's exactly what I have heard. That is why I was kinda wondering the spring rates needed for that cam and then compare to what was installed on the RPM heads. Figured someone who was *** deep in cam info could give me a good idea whether or not that spring was worth a **** for that fast of a ramp on this cam and its lobes. Down the road, I would like to go with a roller cam setup. I was hoping I could get by with this stuff for a couple summers while I get the parts and funding in order to change cams, but I didn't wanna fubar something if it was that bad of a combo.

if you get into spring rates, and I do, the edelbrock may have the edge over the 924 but the high lift has to be a concern. rocker ratio increases usually require pressure increases too. unless you know exactly what your lift is at the valve i'd error on the side of caution. this is why I like those old fashion cams for driving. break a spring, drop a valve, game over.

 

[91r/t]

when in doubt, call the people that made the cam,

Yea just wanted to run it by some guys on here and see if anyone had the combo or any info. Will do if needed.

 

[wyrmrider]

First
The HL XE series cams does NOT "have an extremely fast valve opening and closing rates that are pretty hard on generic or fits all type valve springs."
The are based on a milder design than the more radical chevy grinds- they just use the larger lifter to appear to be more radical
They are not race only hyd profiles
I like dual springs
but what's the problem with putting an Edelbrock spring in a spring tester and plotting the profile?
That said I like dual springs
even with .305 cam lift
tell us about your ride trans, gears, compression, how much vacuum, etc

 

[91r/t]

First
The HL XE series cams does NOT "have an extremely fast valve opening and closing rates that are pretty hard on generic or fits all type valve springs."
The are based on a milder design than the more radical chevy grinds- they just use the larger lifter to appear to be more radical
They are not race only hyd profiles
I like dual springs
but what's the problem with putting an Edelbrock spring in a spring tester and plotting the profile?
That said I like dual springs
even with .305 cam lift
tell us about your ride trans, gears, compression, how much vacuum, etc

It is a 68 Charger with a 4 speed, 3.91 rear gears, and a 29" tall rear tire. 500 in Stroker motor but heres the deal.....it was my buddies car that passed away so I am unsure of the exact compression ratio in it. It has the stroker kit from 440 source and with flat top pistons and the 84cc performer heads it has on it, it makes anywhere from 10.8-10.98 depends on the bore. I am unsure of the bore as I have engine receipts but that section is cut off the form. The car makes 13in/mg. of vacuum which seems alot for this cam. I am told strokers eat up cam size and duration, but I was wondering if that makes it build more vacuum as well or not?I remember when he added the newer cam a few years back, he chose one that actually bound the valvetrain and had too much lift so a little part of me is unsure of wtf is in this motor. I know he bought a smaller cam at the time to fix that issue. In the folder I got with the car it has the cam card and paperwork for the XE295HL, but I was curious if maybe he threw a smaller cam in and never kept the info. Man its hard to figure this **** out when someone is gone ya know......

 

[91r/t]

Ok.......if I were to set up an indicator on a valve and turn the engine over, that would give me approximate valve lift of cam correct? I am just doubting the cam after listening to all the idles of big cams and this car and comparing.I wanna nip it in the bud and end my doubt. The cam has .564 of lift on both exhaust and intake so I should be able to do either. Sorry about the scatter brainness, but its hard not knowing every detail of it because I didn't build the slob myself. All my other motors I have no question, as I started them from scratch.

 

[66Satellite47]

Like lewto said, thr recommended spring is a Comp 924 which a 1,509 OD double spring. The EDE spring is 1.550 single. Don't have the EDE spring in front of me, but they checked just about the same as the Indy single spring I just checked. The Indy spring is real close to the Comp 924 on both 1.900 & 1.350 spring pressures. My slightly used EDE springs checked checked just a little lower than the new Indy springs. I also prefer the double spring. FYI I switched from the EDE spring to a Comp 930 for an antique .565 lift solid cam I put in my 500" motor. If you do go roller in the future, be REAL careful on getting the correct spring for the cam.

 

[91r/t]

Ok.....so I am pissed at myself for starting this thread before checking the cam out.....I just checked the valve spring lift with an indicator and stand and when rolling the motor over I got .430 lift total if I'm lucky. There is no way I am losing .135 lift roughly due to lifter pump correct? I even spun the motor over a few times to pump the lifters up a bit. I am thinking this cam is alot more mild then the cam card in the folder said. I got it close to parallel with the valve stem itself and zero'd it out on the spring retainer on top. It measured .425-.430 total lift on the #1 exhaust valve. So with the lifter bleed down factored in, I am thinking this cam is definitely different then I thought. This car makes 12-14 in/mg of vacuum and maybe that's why.....smaller cam then I thought was in it. Any thoughts on my findings?

 

[66Satellite47]

Check a few different valves to see if the lifts are consistent, or if you've got a worn lobe. A stock 383 low perf cam has .435 Ex lift and .425 In according to my '70 FSM. IMHO a silly choice for a 500" motor. Seems like the XE295HL would be a good choice, but if you want something tamer, go down to a smaller grind. If you want luxo smooth idle, stick with the "stock" style grind.

 

[BSB67]

Ok.....so I am pissed at myself for starting this thread before checking the cam out.....I just checked the valve spring lift with an indicator and stand and when rolling the motor over I got .430 lift total if I'm lucky. There is no way I am losing .135 lift roughly due to lifter pump correct? I even spun the motor over a few times to pump the lifters up a bit. I am thinking this cam is alot more mild then the cam card in the folder said. I got it close to parallel with the valve stem itself and zero'd it out on the spring retainer on top. It measured .425-.430 total lift on the #1 exhaust valve. So with the lifter bleed down factored in, I am thinking this cam is definitely different then I thought. This car makes 12-14 in/mg of vacuum and maybe that's why.....smaller cam then I thought was in it. Any thoughts on my findings?

Checking hydraulic cam timing the way you did will likely give incorrect results, as you implied. I agree with the notion that it's unlikely the 295 based on the limited info you have at this time. Kinda doubt it is a stock as well. A 0.060" lifter bleed down will be approximately 0.090" at the retainer.

 

[91r/t]

Checking hydraulic cam timing the way you did will likely give incorrect results, as you implied. I agree with the notion that it's unlikely the 295 based on the limited info you have at this time. Kinda doubt it is a stock as well. A 0.060" lifter bleed down will be approximately 0.090" at the retainer.

Agreed. Just seems like that much vacuum at idle, plus the fact it isn't very choppy at all, leads me to believe its somewhere in the low to mid .500's range of lift. I went down to his shop last night and looked through a couple cam boxes, but all I could find was the XE295HL box with another cam in it and another cam which I know is in the truck motor we built. I thought I knew the cam in the box isn't the XE295HL because it is a 3 bolt cam and the 295HL is advertised on the cam card as a one bolt. Now I see on Jeg's you can order that same cam with a 3 bolt. I was trying to see if I could match up stuff doing some detective work, but no such luck. SO I then crawled over to 440 source's website and discovered this cam is known for higher vacuum and smooth idle quality, so maybe it is the cam in the car. The 295HL cam they offer also is a 3 bolt design and that is where he bought it as I have the receipt from them. I don't know, but I am at the point of saying F it and just driving the thing and enjoying it. Thanks for the help everyone! So things are better just left alone and untouched.

 

[BSB67]

Maybe, but it's a little hard to think a cam with 82° overlap would idle at that vacuum level, even at +500 cu in. What is the idle rpm?

 

[91r/t]

It'll idle nice and likes between 850 and 900 RPM.

 

[lewtot184]

you can't check lift at the valve with a hydraulic tappet; especially with valve spring. it must be done with a solid tappet and checking spring. the more you rotate a hydraulic lifter with a valve spring the more it bleeds down. to stay pumped a hydraulic tappet must run in pressurized oil. even some checking springs can start to bleed a hydraulic tappet with multiple rotations of the engine.