worship79

Who's running the XE-274H-10 and in what kind of engine (350/383/larger)? Also: what convertor are you using? 64 or larger cc heads?

Building a 383 and looking into the top-end.

Thanks!

cooper9811

I'm intertested in this thread - I just finished my first build (mild 350). Now I'm looking to follow it up it with a 383 - was considering a similar duration cam (retrofit roller XR-276HR) with 65CC AFR 195 heads. Short block is my original L-48 already reworked with splayed 4 bolt mains, scat internaly balanced rotating assembly, line bored and zero decked (I had the block, why not use it?).

Thinking about something like a 2400 to 2600 stall converter, Currntly have a 700r4 and 3.55 gears

FRSTR90

nay... I'd personally steer clear from flat tappet cams... Especially from Comp Cams. I have heard so many horror stories about the flat tapper cams from CC. I'd take a look at their roller cams and have it ground on a billet core with a pressed on iron dizzy gear. Other than that, what do you have (trans and gears) and what do you want?

73, Dark Blue 454

Another 'nay' here as well. Do a search on this site and others, " XE cam wiped lobe" and you'll be reading for weeks.

Go roller,..more money, but more HP and more peace of mind.

1972warship

If you get a comp roller, I would go with a billet core. The standard roller cams are some kind of tempered core. I believe anything with a -8 on the end of the part number is the iron tempered core. The -9 seems to be a billet core, which you would need for them to custom grind for you.

worship79

Thanks for the replies so far

The reason I left out my own specs is that I'm looking for how others apply this cam. When users post their engine specs, they tend to get advice for that specific setup

What I'm looking for is a lot of torque in the lower RPM range, but also good throttle response and power in the mid-rpm range. My TH350 limits operation to 5500, 6000 rpm. And the speed limit... of course...

Desktop Dyno predicts 407 lbs/ft at 2000rpm with 437 peak hp at 5000 rpm. Only simulations versus the real world tends to be different, so any more experiences/opinions are welcome!

Imo Apita

Cooper 9811, just started my 383 build.
Block is at the machine shop as we speak.
My plans are to go with a 700R4 and at some point, to be determined by finances switch to 3.55 rear gears.

Also to the OP; this is the cam that is currently #1 on my list

Howards Max torque series, think Summit sells them.

cboyd

Worship79
I built a 383 last fall using the XE274H. I combined it with Edelbrock Vortec heads with 64cc chambers, Edelbrock RPM Air gap intake designed for the vortec heads, the deck was machined to achieve 10:1 cr. I topped it of with a holly 770 duel feed carb. I am using a 2004r transmission which we built with Red eagle bands, a big servo and transgo shift kit, mated it to the engine with a 2400 stall from B&M.
I was also cautious of the reputation that CC has with their flat tappet cams and did some research and found that our oils of today does not have the wear protection that the oils of the past did. I used JG Breakin oil to run the cam in and then I refilled the engine with JG Hot Rod Oil.
I have only taken a few short runs up the driveway so far because the car is being restored. I must say with the hooker SS side pipes, spiral baffles, the 274 cam the engine has a nice lumpy idle and very good throttle response. I cannot testify to the longivity of the cam as we haven't had it on the road yet.
C

bobs77vet

i have one step down from that with an xe268h and it is lopey lots of power and sounds sweet, i have a 700r4, 355 cid 350hp 425 ft lbs, 2500 stall speed headers true duals and an h pipe. original fuelie heads (small valve) edelbrock performer. it has lots of umph. i personnally think most of the wiped cam lobes were from guys not knowing what they were doing, using used lifters, not letting the cam break in at a high rpm, not using oil with ZDDP in it and not using a break in oil supplement......since the industry has aggressively started educating people about this the number of "failures" has reduced substantially and it was not limited to comp cams.

having said that i think roller lifters are the way to go if you have the $$$

painterman52

I have that cam. It`s been 2 years now. I use the good oil and a supplement. I like the cam, I have edelbrock rpm heads and rpm intake, It`s a 383. I think it`s a real nice street motor. 4 speed with 3.70 rear

63mako

Comp XE series flat tappet cams have aggressive almost roller profile ramps. That said all flat tappet cams have higher failure rates as many competitors have increased the ramp rates of their lobes to stay competitive on the dyno. Comp sells more XE cams than all the others combined so you hear about more failures.
That combined with all the comments from Bobs77vet leads to these failures. They design these with steep ramps to get the most power for the $ but it is a roll of the dice as far as longevity goes. It is cheaper to buy 1 roller cam than have a failure with a flat tappet cam and then have to buy a new roller and possibly incure further engine damage that needs repaired due to a prematurely wiped lobe.

73, Dark Blue 454

Flat tappet cams are quickly becoming a thing of the past. It's interesting that in the new GMPP (GM Performance) catalog, it lists only two flat tappet cams for SBC's. None are listed for BBC's.

With the hundreds or thousands of reports of wiped lobes with the XE line of cams and others, I think it would be wise to go roller. Do a search on this site and others, "wiped XE lobe" and you'll be reading for weeks.

Here's some good reading:

http://www.reginaantiqueauto.ca/Oil/aeratb2333.pdf

http://blog.motorists.org/warning-if...oil-carefully/

http://www.performancejet.com/ttengineolialert.html

http://www.economist.com/blogs/babba...ibology?page=1

http://www.compcams.com/Technical/In.../Files/255.pdf
(see page 2 of the above)

http://www.kirks-auto.com/Oil_101_byRobertKirk.html

http://www.vscda.org/cars/pdfs/Bulletin4.pdf

http://www.ohiomotorpool.oldmv.com/h...oration-tv.htm

http://www.britishmotoring.net/curre...901_How-To.pdf

http://www.aera.org/ep/downloads/ep1/EP012008_8-16.pdf

http://www.synmaxperformancelubrican...n_MotorOil.pdf

http://www.highperformancepontiac.co...oil/index.html

http://www.reginaantiqueauto.ca/Oil/oils.htm

http://www.reginaantiqueauto.ca/Oil/keith_ansell.htm

http://www.enginebuildermag.com/Arti..._got_zinc.aspx

http://www.widman.biz/uploads/Corvair_oil.pdf

http://www.laidbackboatersboard.com/...lert-t173.html

http://www.hotrod.com/techarticles/e...l_summary.html

http://www.mobiloil.com/USA-English/...t_Engines.aspx

worship79

Thanks for the input! Personally I think going roller is as much a risk for me as choosing a (too) steep flat tappet pattern. My block isn't a roller and most conversion techniques I read about are out of my league of expertise. The requierd expertise is available in The Netherlands, but only at great expense.

Unless there is a bolt on roller conversion kit?

I agree with both users saying the XE series are great bang for the $ and that an agressive profile brings concerns. So I decided looking into using the same cam Bob's using (XE268H) and the simulator actually gives me better tq/hp numbers. Also this cam seems to like the stock convertor better, which is a plus.

Where do I find a price tag for a CompCam billet core? I tried their search engine, but only see prices for accessories (timing covers and such) or LS cams. I'll send them an e-mail too of course.

I'll also give the Howards Max Torque a run, but haven't had the time for that. Should get to that this weekend. And I'd like to thank "73, Dark Blue 454" for filling the rest of my spare time with yet more reading material

Imo Apita

Roller conversion is not that hard and I sent you a PM.

SteveG75

OK. Here is my story.

Had a Comp XE-262. Wiped lobe within 2000 miles. Replaced with XE-274. Wiped within 200 miles.

Personally, I think the ramps are way to aggressive on the Comp XE flat tappets.

Got a Crane roller and it works great. Got their full kit with retrofit roller lifters that dropped right in and correct length pushrods. For a button, I used the Cloyes timing chain cover with adjustable button. Slick piece.

Overall, it was an expensive conversion (about $800 total) but the peace of mind is worth it and I have many miles with no issues. One of the nice side benefits is that I can now swap cams with changing lifters so the biggest expense is a one-time cost.

63mako

Here you go. Hydraulic intensity is one of the main contributing factors to cam failures today. This hasn't been addressed on this post. We want the most power for the least $. All the cam companies want to be competitive. They want great dyno numbers at low cost and the most recent favorable write up in the high performance magazine. This has resulted increasingly steeper ramps in the performance flat tappet cams across the board. This higher hydraulic intensity increases the load at the lobe-lifter interface drastically. Combine this with decreased ZDDP and you have a recipe for disaster. It will make great power at a cheap price but for how long?
http://www.enginebuildermag.com/Arti...r_failure.aspx

worship79

Interesting. But how about just forking say $100,- (guestimate) extra and use a billet hyd. flat tappet cam? More reliable, yet cheaper than the conversion.

Perhaps I should explain my reluctance to go roller: My shortblock is just about done. Bored, honed, decked, crank is in, pistons as well.

Also I don't have the budget for an $800 conversion. Considering other purchases yet to be made I'm around $300 - $400 for cam and lifters.

LB66383

I have the XE268H in a 383 with 64cc aluminum heads, 195cc intake ports, an airgap manifold, and headers. I don't know the horsepower/torque, but I can get the car sideways in first and second gear, and chirp the tires going into third (Muncie 4-speed). It'd probably do more, but I haven't pushed it any harder than that, I have yet to put the pedal all the way to the floor. So your engine should have more than enough to entertain you and anyone else on the street.

gkull

I actually had a 274 cam in a hot rodded 355 engine in my Vette with a 3500 stall 9.5 inch convertor (700R4) with 4.11 year end. 750 carb weiand single plain, 200 cc heads, flat tops with 64 cc chambers, and headers.

First of all I would not buy a junk prone to failure pot metal cam from comp cams in the first place!

I would buy a like cam from another vendor. IMO - With my setup and only 355 ci it was pretty lazy sub 3000 rpm and then it cam on pretty good to over 6000 and tapered off by shift time of 7000 rpm

It would be better suited to 383 class motors with an auto tranny or 350's with smaller cc heads and a dual plane setup

worship79

@gkull Allright, which vendors would you prefer? Crane, Crower, Edelbrock, Lunati?

I hear and read positive remarks about the voodoo cams.

@LB66383 I have the XE268H in a 350, good to hear it actually does perform well in a 383. Your specs resemble mine, except for the airgap and muncie.