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#1
03-10-2010, 11:25 AM
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Quote:
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"XE cam basher" 
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#2
03-10-2010, 01:16 AM
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Quote:
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Carburetor building & modification services Servicing the Pontiac community over 25 years |
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#3
03-10-2010, 12:41 AM
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It would be nice to know the engine specifics, true static compression ratio, headers or stock iron manifolds, intake used and if it was ported, etc, etc, etc?
Peak torque is good for the combination of parts, and is occuring EXACTLY where it has with every XE274 cammed 455 dyno test I've seen, which is about 400rpm earlier in the rpm range than either the Crower 60919 cam or our "custom" HR cam of similiar specs. What was the torque number at 4900rpm's? Same thing with peak HP, 4900 is EXACTLY where every single 455 quit that used that cam, even with very good flowing heads on them. FWIW, we built a stock 455 SD engine here couple of years ago. No grinder or sanding roll touched anything. It was zero decked, and aftermarket forged rods and pistons were used, but the owner insisted on all stock components otherwise without any "mods". We were able to convince them to upgrade to a small HR camshaft, which I chose from Comp Cams. 230/242/112 with .361" lobes. That engine cranked out over 440hp and 550ft lbs torque. Peak HP at 5400rpms, and peak torque at 3900rpm's.....FWIW.....Cliff
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If you can read this, thank a teacher. If you can read this in English, thank a Veteran! https://cliffshighperformance.com/ 73 Ventura, SOLD 455, 3740lbs, 11.30's at 120mph, 1977 Pontiac Q-jet, HO intake, HEI, 10" converter, 3.42 gears, DOT's, 7.20's at 96mph and still WAY under the roll bar rule. Best ET to date 7.18 at 97MPH (1/8th mile), |
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#4
03-10-2010, 01:12 AM
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SD Clone recieved Specs:
Jets 75 Pri Rods .049" I-tubes .035" I-Chan .049 U&L AB's .069" By-air .109" (factory passage plugged & plates drilled) N&S .122" Sec Rods "CR" .055" short tip "R" Hanger Recal: Jets 75 Pri Rods .041" tip (Resized w/ 1.50 degree taper) I-chan .052" N&S .136" ( resized w/ .136 reamer & deburred, pres tested) Sec Rods "CR" .030" (Machined, taper blended)
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Carburetor building & modification services Servicing the Pontiac community over 25 years |
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#5
03-10-2010, 08:17 AM
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"It would be nice to know the engine specifics, true static compression ratio, headers or stock iron manifolds, intake used and if it was ported, etc, etc, etc?"
In addition, what was the torque production at 4900rpm's?.....Cliff
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If you can read this, thank a teacher. If you can read this in English, thank a Veteran! https://cliffshighperformance.com/ 73 Ventura, SOLD 455, 3740lbs, 11.30's at 120mph, 1977 Pontiac Q-jet, HO intake, HEI, 10" converter, 3.42 gears, DOT's, 7.20's at 96mph and still WAY under the roll bar rule. Best ET to date 7.18 at 97MPH (1/8th mile), |
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#6
03-10-2010, 09:54 AM
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The engine was run on headers (my manifolds are cracked), compression must be close to stock, it has flat top pistons, heads are untouched, stock sd intake no port matching or anything, pretty much stock except for cam.
Now I'm sure there are better cams that make more power, but that wasn't what I was going for. It's not a pure stock engine or anything, just a show car. It was put on the dyno to basically break in the cam, check for leaks and make sure the bugs are were worked out BEFORE it went into the car and there were some. Like the brand new crane xr-i points conversion module not working out of the box! We got another one yesterday and it worked great. Hp/Tq numbers were just a bonus. Jeff and Lenny are great guys! I tried to scan the dyno sheet, but my scanner isn't working? Rpm Hp Tq 2800 269.1 502.0 2900 270.7 490.5 3000 292.0 510.3 3100 309.0 523.8 3200 318.8 523.4 3300 333.9 530.5 3400 345.5 534.8 3500 352.2 528.3 3600 363.7 530.4 3700 369.5 524.7 3800 378.3 522.5 3900 385.0 518.3 4000 391.2 513.9 4100 397.7 509.4 4200 401.8 502.6 4300 408.5 498.2 4400 403.9 482.6 4500 399.4 466.2 4600 398.4 455.1 4700 402.7 449.8 4800 410.7 449.3 4900 412.9 442.5 5000 415.1 436.1 5100 409.1 421.4 5200 408.4 412.3 5300 408.2 403.6
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1972 Trans Am white with blue deluxe interior 1974 SD Trans Am white with tuxedo interior, earliest known 74 SD vin# 1976 50th Anniversary Trans Am 1970 Judge ra3 4 speed pepper green 
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#7
03-10-2010, 10:45 AM
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Thanks for the numbers. As I suspected the upper mid-range and top end power is WAY down for the size of the cam. Not to bust on your engine in any way, but we continue to hear how good the XE274 camshaft is, and again it didn't deliver anything but a decent peak torque number, and once again quits at the magic 4800-5000rpm number, if anyone is paying attention?
FWIW, a couple of years ago KRE unintentionally ported a set of 4X heads and they had the HUGE chambers. Since they had so much work into them, they installed them on a 455 with flat top pistons. On the dyno the engine made just shy of 1hp per cid, and the torque curve was as flat as Kansas, with over 500ft lbs on tap clear across the useable rpm range. It was even making 500ft lbs at 5000rpm's (499)!!! The cam was the Crower 60919 (231/240/113), with .470" lift. Basically a near duplicate of the factory RAIV camshaft........Cliff
__________________
If you can read this, thank a teacher. If you can read this in English, thank a Veteran! https://cliffshighperformance.com/ 73 Ventura, SOLD 455, 3740lbs, 11.30's at 120mph, 1977 Pontiac Q-jet, HO intake, HEI, 10" converter, 3.42 gears, DOT's, 7.20's at 96mph and still WAY under the roll bar rule. Best ET to date 7.18 at 97MPH (1/8th mile), |
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#8
03-10-2010, 10:55 AM
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Again, this is a show car! I wasn't out to make the most power possible. It doesn't matter to me that it would make more power in the upper rpm range when it will never go there. I have too much into this car to be irresponsible with it. We are building another 455 with another set of sd heads I have. That one will be a different story!
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1972 Trans Am white with blue deluxe interior 1974 SD Trans Am white with tuxedo interior, earliest known 74 SD vin# 1976 50th Anniversary Trans Am 1970 Judge ra3 4 speed pepper green
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#9
03-10-2010, 11:18 AM
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Jeff, how'd you get the boosters to stay in place? Also, what mods to the '71 HO Q-jet?
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#10
03-10-2010, 06:32 PM
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Quote:
The venturi was machined to accecpt a press fit and booter rings were machined to fit into place in the same manner I made some machined parts to repair three rare Qjet castings for Cliff. Maybe he can post some pics? The 71' HO has standard mods to the idle & primary circuits that GTO Carl posted years ago....runs nice!
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Carburetor building & modification services Servicing the Pontiac community over 25 years Last edited by shaker455; 03-10-2010 at 07:22 PM. |
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#11
03-10-2010, 07:45 PM
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Cliff FWIW your XE274 mantra is getting old, you need to let go and find something else to complain about. I'm not impressed with the cam either but I don't go around telling people how they built their engines wrong because they used it. I think he already expressed his goals and that he's happy. Leave it alone.
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#12
03-10-2010, 01:57 PM
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"It doesn't matter to me that it would make more power in the upper rpm range when it will never go there."
What should be important to you is the spike in cylinder pressure at peak torque and relatively low in the rpm range, followed by a sharp drop of power (torque) to where peak HP is produced. In any case, just pointing out that the XE274 cam, once again came up WAY short on power production for the advertised specifications. We see this again and again, and still folks defend these parts to the death. What is really important here is that you are happy. What is equally as important is that the readers see how much power is left on the table using these particular parts. On a personal note. I would be quite disappointed that an engine with the potential of the Super Duty came up so short on upper mid-range and top end power, as it sports the some of the best flowing heads the Pontiac engineers ever developed (and we gave it a "modern" whiz-bang cam profile to bring out the very best of them). They were clearly intended to make power well beyond 4900rpms, you could have made equally as much power running a stone stock set of 4X large chamber heads on that engine...FWIW....Cliff
__________________
If you can read this, thank a teacher. If you can read this in English, thank a Veteran! https://cliffshighperformance.com/ 73 Ventura, SOLD 455, 3740lbs, 11.30's at 120mph, 1977 Pontiac Q-jet, HO intake, HEI, 10" converter, 3.42 gears, DOT's, 7.20's at 96mph and still WAY under the roll bar rule. Best ET to date 7.18 at 97MPH (1/8th mile), |
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#13
03-10-2010, 07:40 PM
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Jeff, the castings are long gone from here as folks needed them. The fuel inlet seat repairs work perfect. However the float fulcrum repairs didn't pan out so well. Although the intricate machining was fantastic, they were simply too wide at the power piston tower, requiring the float arms be bent out excessively. This caused too much tension and the floats hung up in actual use.
I was able to obtain some near identical stamped steel peices to make the repairs. The stamped steel parts, being a lot thinner, did not interfere with the pivot action of the floats...FWIW....Cliff
__________________
If you can read this, thank a teacher. If you can read this in English, thank a Veteran! https://cliffshighperformance.com/ 73 Ventura, SOLD 455, 3740lbs, 11.30's at 120mph, 1977 Pontiac Q-jet, HO intake, HEI, 10" converter, 3.42 gears, DOT's, 7.20's at 96mph and still WAY under the roll bar rule. Best ET to date 7.18 at 97MPH (1/8th mile), |
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#14
03-10-2010, 08:34 PM
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Quote:
Little bit of clock work.
__________________
Carburetor building & modification services Servicing the Pontiac community over 25 years |
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#15
03-10-2010, 08:02 PM
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Good point. An because a lot of folks bought into the BS about those cams being so great, we have a LOT of customers very unhappy with their VERY EXPENSIVE engines. Keep in mind that a LOT of enthusiasts aren't simply happy with OK power, they want the best power they can produce from the combination of parts on modern pump gas.
My goals here are to help folks, unfortunate at times we have to point out the reality of the situation(s). I'd rather point out the shortcomings of certain parts, than to have to spend hours on the phone with someone who installed the parts and is quite disappointed with the results. In any case, you are correct that it is time to move on to something else. I have been waiting for a dyno test like this one, from a reputable source, and the results as expected, duplicated EXACTLY what we have seen many, many times before. Hard to argue another test clearly showing us the very same thing. I don't consider this good news, and take no pleasure in having to point out the shortcomings, etc, but facts are facts, and folks need to have this information available to them when selecting parts, etc.....LOL....Cliff
__________________
If you can read this, thank a teacher. If you can read this in English, thank a Veteran! https://cliffshighperformance.com/ 73 Ventura, SOLD 455, 3740lbs, 11.30's at 120mph, 1977 Pontiac Q-jet, HO intake, HEI, 10" converter, 3.42 gears, DOT's, 7.20's at 96mph and still WAY under the roll bar rule. Best ET to date 7.18 at 97MPH (1/8th mile), |
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#16
03-10-2010, 08:22 PM
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Listen guys, my post was not meant to prove or disprove anyones theories about a particular cam. This is the cam I used because I wanted to use it, period! No one talked me into or out of it. This post was just to give the Pontiac community info on my results from my sd455. I'm sorry I posted my numbers. I find it hard to believe someone would be "disappointed" with those numbers on a STREET driven, Sunday driver! I know I won't be.
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1972 Trans Am white with blue deluxe interior 1974 SD Trans Am white with tuxedo interior, earliest known 74 SD vin# 1976 50th Anniversary Trans Am 1970 Judge ra3 4 speed pepper green
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#17
03-10-2010, 08:40 PM
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As I posted eariler not a fan either of XE that's why we have Lenny Caverly's Jeckle & Hyde cams in our own stuff! 
__________________
Carburetor building & modification services Servicing the Pontiac community over 25 years |
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#18
03-10-2010, 09:30 PM
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Quote:
 I have a feeling the dyno numbers will look a bit different on that one! 
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1972 Trans Am white with blue deluxe interior 1974 SD Trans Am white with tuxedo interior, earliest known 74 SD vin# 1976 50th Anniversary Trans Am 1970 Judge ra3 4 speed pepper green
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#19
03-10-2010, 11:24 PM
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"And that's why he's designing the cam for the monster you are building for my 76t/a"
I heard he was going to use the XE284 grind, because it will pull to 6000rpm's and make at least 600hp!!! Seriously, stick with Len, he knows his way around the power production deal with these engines, you will NOT be disappointed anyplace......Cliff
__________________
If you can read this, thank a teacher. If you can read this in English, thank a Veteran! https://cliffshighperformance.com/ 73 Ventura, SOLD 455, 3740lbs, 11.30's at 120mph, 1977 Pontiac Q-jet, HO intake, HEI, 10" converter, 3.42 gears, DOT's, 7.20's at 96mph and still WAY under the roll bar rule. Best ET to date 7.18 at 97MPH (1/8th mile), |
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#20
03-10-2010, 11:35 PM
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It's a damn shame what happen to him at Engine Masters though!!!
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1972 Trans Am white with blue deluxe interior 1974 SD Trans Am white with tuxedo interior, earliest known 74 SD vin# 1976 50th Anniversary Trans Am 1970 Judge ra3 4 speed pepper green
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