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 461 rebuild at 350,000 miles
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DanM
Cochise

230 Posts

Posted - 11 Nov 2019 :  1:49:01 PM  Show Profile  Reply with Quote
Let's do this again. It seems so much fun to talk about so I don't mind asking the same question everyone else has asked.

Let's help me select a cam for my rebuild. After 90,000 miles the #3 connecting rod is failing so I will upgrade my 400 to a 461. I would like a cam that will idle and drive somewhat similarly to a 218 degree intake duration at 0.050" would in my 400 such as the XE262 but with 112 LSA and 112 ICL. I believe I prefer the bigger numbers for LSA and ICL in order to improve idle vacuum.

Some specifics:
All the usual stuff: Qjet, Pontiac iron dual plane intake, HEI, Doug's headers, 3.55 rear gears, 4L60E trans with its low first gear, torque converter stall around 2000ish. #96 heads with sportsman porting which means about 240 cfm at .500 in intake and 90cc chambers, large valves,

I commute in this car so I need to be able to idle and drive in rush-hour traffic.

I'm thinking about getting the XE274H. That's 230 degrees and 0.490 lift on the intake. I wish it has more lift ~0.510 but oh well. Or I may get the Lunati Voodoo 703 but with LSA and ICL at 112. Again the lift (.489) is is little shy of what my heads can make use of.

If I use the Comp Cams 995 springs again, I could install 1.65 rockers and be ok vs coil bind if I'm careful to have the installed height perfect.

An option is to err on the small side of the cam (XE268H), use 1.5 rockers, and if I find I can tolerate more then install the 1.65 rockers to "grow" the profile by about 3 degrees. OR is a 230 degree cam ALREADY being cautious for a 9.5:1 compression 461?

So in summary here are some options listed in shorthand
XE268 - 224 degrees
Voodoo 703 - 227 degrees
XE275 - 230 degrees
Voodoo 704 - 233 degrees

Note: isn't that interesting how Lunati has set its cam lobes to be in between the Comp Cams? Almost as if they decided not to compete head to head but to be an alternate?

note v2: I would like a tad more oil pressure. Currently I get 40 psi at highway crusing around 2500 rpm. At idle is falls to 10 or less. In fact I purposely have my idle set a tiny bit high just to make sure the oil pressure doesn't get too low. I actually prefer the "about to stall" idle sound but the pressure was barely above 5. I think I would rather idle at 20 and cruise at 50 and max at 70. What say you?

71 LeMans Sport Convertible with 350,000 miles driven year round since 1994.

Corncob2061
Crazy Horse

USA
628 Posts

Posted - 11 Nov 2019 :  3:17:14 PM  Show Profile  Reply with Quote
Oil pressure does seem a little low. 90k, it served you well.

It does appear comp and Lunati have those cam series so one bridges a gap to the next. But keep something to keep in mind looking at advertise numbers, those XE profile put a rocket booster on the lifters acceleration compared to the Lunati voodoo series. The lunati 268/276 compared at the same lifts with an XE 274 looks like 273/281 227/233 versus 274/286 230/236. Comparatively the XE profile is an asymmetrical torque profile (XE intake and Magnum profile on the exhuast) and the Lunati is a fairly aggressive higher rpm asymmetrical profile. The 1.65 rockers make the XE 274 look more like 275/287 234/240 out at the valve. Even more acceleration. It should clean up and adsorb more cam using the XE series. But it comes at a cost. More valve noise and some lost valve terrain stability. My friend had mid to low 9s scr, 462 with fully ported 96s, RPM, q jet and RA manifolds. 5k it was done, and you could tell peak power was probably 4500. It sounded like a stock cam at idle even with the stock 110 lsa, it had a huge burst of mid range though. It was on the ragged edge for pump gas. I think Butler stocks the XE 274 on 112LSA. That would be friendlier on pump gas and be a tamer idle than the off the shelf 110 lsa. A XE268 on a 112 lsa in a 462 would idle like a stocker. I would probably look hard at the Lunati 703 and have Lunati widen the lsa out to 112 over the XE. But you can make the XE work too, but it will likely nose over sooner on power and rpm unless you pick a bigger profile. Jay
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DanM
Cochise

230 Posts

Posted - 11 Nov 2019 :  5:20:11 PM  Show Profile  Reply with Quote
I wonder if it is possible to get accurate estimates for idle vacuum as well as peak HP and/or 1/4 times for these cam options
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Corncob2061
Crazy Horse

USA
628 Posts

Posted - 11 Nov 2019 :  7:15:03 PM  Show Profile  Reply with Quote
What altitude and at what SCR are you shooting for? Jay
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DanM
Cochise

230 Posts

Posted - 12 Nov 2019 :  12:38:24 AM  Show Profile  Reply with Quote
9.5:1
Sea level
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DanM
Cochise

230 Posts

Posted - 12 Nov 2019 :  10:07:52 AM  Show Profile  Reply with Quote
As a reference, my current 400 measured 290 HP on the chassis dyno and runs 13.8 at 97 mph.

For this rebuild everything stays the same except
400 ci becomes 461
215 deg cam becomes 227-230
8.9:1 compr becomes 9.8:1
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Corncob2061
Crazy Horse

USA
628 Posts

Posted - 14 Nov 2019 :  01:27:51 AM  Show Profile  Reply with Quote
I will try to run some dyno sims and see what the hp and vacuum is estimated at. But overall looking at what your expectations are for the vacuum and running 9.8 SCR in a 462 the XE 268 will be to small, even with the 1.65s at the wider lsa separations, too much compression. The XE274 out on 112 lsa would be closer to working at 9.8. That is probably on the edge of not working on pump gas. Guessing about 16 for vacuum. The lunati 703 out on 114 with the 1.65s would probably make about as much power as the xe274 112 lsa combo and have about 18 inch of vacuum, but it is also close to not working at that the 9.8 scr. Rough guess anyway. I think the 9.5 scr on those in a 462 is a better target than 9.8, unless the cam profile is bigger. Jay

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DanM
Cochise

230 Posts

Posted - 14 Nov 2019 :  12:31:52 PM  Show Profile  Reply with Quote
Jay,

Thanks for the insight. I would be perfectly happy to use a bigger cam if that is what it takes to drive on 91 or 93 octane with 9.8:1 scr. In fact it's the other way around. BECAUSE I will be at 9.8 I will be ABLE to use a bigger cam and still commute in it.

So with that perspective let's try to pick the right cam.
XE274H (the next size up is probably too big a jump, XE284H)
or
Lunati 703
or
Lunati 704
or, here's a curveball,
XR276HR or XR282HR (roller cams).

Short question just to help bound the problem. Do we agree that the XE284H is simply too big for my uses?

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DanM
Cochise

230 Posts

Posted - 14 Nov 2019 :  12:43:52 PM  Show Profile  Reply with Quote
Jay,

Also, I would most likely have the ICL at 112 also. That would ease the problem with knocking with pump gas and also extend my power band up a few 100 rpm.
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tjs44
Crazy Horse

USA
659 Posts

Posted - 14 Nov 2019 :  2:26:29 PM  Show Profile  Reply with Quote
I just looked at the results of my friends 455 with 6X heads.Rod bearings down to copper on the upper shells,cam bearings all shot.Had a history of running hot.Too small of cam ground on a 110.Going to need a full ground up rebuild.Tom
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Corncob2061
Crazy Horse

USA
628 Posts

Posted - 14 Nov 2019 :  11:34:31 PM  Show Profile  Reply with Quote
Tom, out of curiosity, was the cam your friends 455 a hft or a hyd roller?

Dan the XR276HR is to small. The XR282HR is even really a bit to small with it out at 114lsa. At 9.8 scr in a 4.25 stroke engine the XR288HR with a 114 lsa is as small and I would look at. The XR288HR with a 112 lsa is probably a 9.5:1 cam in a 455.

Back to the hft cams. I do not think you would not be happy with the XE284 even on a 112 lsa, it is getting big. They do have a profile in between which is the XE278, could do that on a 112 lsa. I would need to do a bit of research for pairing a exhuast profile with it. I prefer some more seat duration for running high compression, which does not describe an XE profile. But we did do a 466 Pontiac with a compcam similar to an XE type profile that had 10.3 SCR compression and 96 heads. It was a solid cam, but in a hydrualic profile it would run similar to a 283/291 246/254 112 lsa hydrualic. It was pretty wicked sounding even at the 10.3 scr.

Over on the lunati side the 704 with a 112 lsa would be a good cam to look at.

I had Bullet grind an Ultradyne 280/288 232/240 on a 112 lsa with 1.65s, .550/.550 and 995 comp springs. It is a close cousin to the lunati 704, 704 cam card use to read 281/289 233/240 233/241, which is within 1 degree of the UD. Might be worth looking at too, talk to Tim at Bullet. I like the lift of the 280/288 UD cam, the 704 is a little high on the lift with 1.65s. Not real easy to find valve spring for that combo, 995s hit coil bind on the exhuast. Jay

Edited by - Corncob2061 on 14 Nov 2019 11:52:06 PM
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tjs44
Crazy Horse

USA
659 Posts

Posted - 15 Nov 2019 :  11:00:13 AM  Show Profile  Reply with Quote
It was a HFT cam.Tom
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DanM
Cochise

230 Posts

Posted - 15 Nov 2019 :  12:44:00 PM  Show Profile  Reply with Quote
Jay,

Thank you very much for your insight.

I see you are a fan of the bigger cams for good reasons. You make a strong case for them. Now, unfortunately, I am back in a decision mode of uncertainty.

Mr. Butler and I have been emailing about cam selection. He might not be as aware of my engine history as you are so that should be kept in mind. In the end he was advising me toward the milder cam side of things: XR276R. Now his reasons I believe have more to do with the power band working with my 2000 stall torque converter.

I can pick an ICL to be cautious against knocking (114), and I can pick an LSA to help me idle well (114). Those are details I will have to decide. But first I think we need to help me really choose "mild" XR276HR vs "medium" XR282HR vs "wild" XR288HR.

note: I've pretty much decided on a roller cam. I know it's more expensive but the entire rebuild is so much that I think I need to just do it and take advantage of the modern technology.

So one more thing to consider. 1/4 mile time vs ease of commuting all year round.

Here's my thinking:
"mild" cam: HP ~365, 1/4 mile time ~12.9, driveability: smooth
"medium cam": HP ~375, 1/4 mile time ~12.8; driveability: rough
"wild cam": HP ~385, 1/4 mile time ~12.7; drveability: very rough

Are these three summaries valid? Is 20 HP difference really what I'm looking at? And is it really only 2 tenths of a second difference (according to Wallace ET calculators)?
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tjs44
Crazy Horse

USA
659 Posts

Posted - 15 Nov 2019 :  1:12:59 PM  Show Profile  Reply with Quote
FWI on a 455 build
http://forums.maxperformanceinc.com/forums/showthread.php?t=804201
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Corncob2061
Crazy Horse

USA
628 Posts

Posted - 15 Nov 2019 :  1:58:03 PM  Show Profile  Reply with Quote
You have a low gear set in your trans. I would not be worried about the 2k stall with a 4.25 crank with any of the cams your looking at. Your likely going to be back peddling getting it to hook unless you have a 255-275/60 Drag radial.

Pump gas to me means 91 octane. At 9.8 with the 276 with the 1.65 rockers out at 114 might do ok on 93 octane. I still would not drop below the 282 comp roller at 9.8 scr. It would friendlier with and easier to tune. I can look closer at the xr276 114 lsa combo and make sure I am not overlooking something. My opinion though is that cam does not really gain much from the extra compression your thinking about running, were the bigger cams would. Plus those bigger cams out on 114 lsa make them pretty friendly for the street. I think your on the right track with the 114 lsa. Comparing those I need to look at the overlap and the valve event closer. Jay

Edited by - Corncob2061 on 15 Nov 2019 2:01:11 PM
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DanM
Cochise

230 Posts

Posted - 15 Nov 2019 :  3:46:54 PM  Show Profile  Reply with Quote
tjs, thank you for the link. That thread had some very relevant numbers.

Jay, thanks also. I think I'm now going to assume the XR282HR as my default and see how my subconscious thinks about it for a while. I would not have thought in terms of the bigger cam being easier to tune but I guess that's kind of the point with going the higher compression. And, it's more important a factor to me.

The more I think about this the more I want longevity and driveability to matter. I'd like to get 200,000 miles out of the engine this time. That means the oil pump will be a big deal.
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Brian R
Crazy Horse

USA
1734 Posts

Posted - 22 Nov 2019 :  12:26:42 PM  Show Profile  Reply with Quote
XE274H is a noisy ass highly annoying cam Go Lunatti. I absolutely hate the XE in my 461.
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DanM
Cochise

230 Posts

Posted - 16 Dec 2019 :  3:30:11 PM  Show Profile  Reply with Quote
Update:

One of my heads has a crack between the center two chambers. Upon close inspection one can see it was repaired in the past. So, that means I need to get a new pair of heads. I've decided to get a pair from SD Performance. #96 heads, the works.

Cam: going to be a roller cam designed by Dave Bisschop. We won't be as aggressive as he normally would because I hope to get 100,000 miles out of this engine. So 230 degrees at 0.050" for intake. He usually can get about 0.600" of lift but we will back of to about 0.550" to give more life to the springs.

Bottom end. The block is not cracked thank goodness. the cylinders were honed and cleaned and measure 0.045" overbore (4.195") After we get the status on the deck height we will see about Ross pistons and the lead time. We might need to overbore to 0.060" but I'd rather not. I need to leave some metal for my next rebuild (and the one after that...)

I'll get the 4.25" stroke forged crank, BB chevy rods. For bearings we will get the ones that are one step below race hard so that the softer bearings last longer. That's what my engine building suggested.

that's it for now.

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DanM
Cochise

230 Posts

Posted - 16 Dec 2019 :  3:34:05 PM  Show Profile  Reply with Quote
Oh! The XE cam 212/220, 116 LSA 112 ICL.

90,000 miles. Wow were those exhaust lobes trashed. It's a miracle that I still managed 13.8 in the quarter mile. Like, seriously. Those exhaust lobes were really beat. Says a lot for low lift flow. I wish I had a picture to post.

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Steve C.
Chief PONTIAC

2125 Posts

Posted - 17 Dec 2019 :  08:59:49 AM  Show Profile  Reply with Quote
Personally I'd be very wary about using Comp 995 valve springs, period ! But that's my .02 and based on lots of posted issues with their use over the years with different cams, not just XE lobes.

HINT.... as an observation I suggest you now take a few of those old 995 springs and have them tested at their installed height with their retainers used and see how much pressure they currently have !

And I'd be very interested in what Dave Bisschop says regarding the spring pressure in conjunction with his hyd roller cam suggestion. More often than not it's minimum 145+ on the seat, this AFTER run in.

.

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Corncob2061
Crazy Horse

USA
628 Posts

Posted - 17 Dec 2019 :  7:42:20 PM  Show Profile  Reply with Quote
90k is a good run for an XE.

It would be fun just to walk through Bisschops inventory of parts. He must have quite an inventory of Pontiac stuff.

You might want to drill out the block between the exhuast ports for some more cooling, engine must have gotten hot and caused that crack. That is the down side of having those to center exh ports close together. Jay
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Steve C.
Chief PONTIAC

2125 Posts

Posted - 17 Dec 2019 :  9:11:25 PM  Show Profile  Reply with Quote
Indy Cylinder Head is well noted for repair work. We have used them before on a very expensive set of race ported d-port heads.

http://www.indyheads.com/about.html


.
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DanM
Cochise

230 Posts

Posted - 20 Dec 2019 :  10:19:54 AM  Show Profile  Reply with Quote
Steve (et al.): We must think alike on this one. I had the shop measure the seat pressure and installed height on all the springs prior to disassembly of the heads. I have a Moroso spring pressure gauge and wanted to calibrate it. The results said two things.
1) my cheap Moroso gauge was accurate!
2) my 995s were soft. They were consistently at 90 pounds instead of spec 120 at the correct installed height. The cam had 90,000 miles but those springs only had 40,000.

Dave has selected a different set of springs. I don't remember the exact number at the moment. His design is based around higher lift (~0.550" - 0.600") so the springs need to handle that. We will use an installed height of 1.800 instead of 1.650 which is more common. He will have to either use longer valves or machine the head (most likely machine the pockets.) We are also going to use roller lifters thus the seated pressure will be 150 and open about 350.

Update on the hardware. My block deck is 10.215. We want to put on a fresh surface and allow for variability of the cylinder locations so I requested a rotating assembly that targets 10.205". The bore cleaned up nicely with just a little honing but is 0.045" over stock. We want to save as much metal as possible to allow for future rebuilds. Thus I've purchased custom Ross flat-top pistons for this setup.

For anyone who cares.
Scat forged crank 4.25" stroke, 2.2" rod journals
Scat H-beam BBC rods 6.800", 8740 bolts
Clevite 77, H series bearings
Total Seal rings
Ross forged flat top, 4.165 bore, 1.280" compression height
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tjs44
Crazy Horse

USA
659 Posts

Posted - 20 Dec 2019 :  10:52:22 AM  Show Profile  Reply with Quote
Dan,make sure you get the narrow rod bearing!Tom
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Steve C.
Chief PONTIAC

2125 Posts

Posted - 20 Dec 2019 :  4:21:02 PM  Show Profile  Reply with Quote
I've seen similar circumstances with the 995 spring.

Regarding a hyd roller lobe....

"...in most applications we use the Crane 99893 valve spring, installed at 1.790-1.810", I set the intakes on the tighter side of the tolerance, I test all the springs and always put the ones with the higher pressures on the intake valves, since the intake valves weigh more and also have the momentum of the charge pushing on the back side of the valve while the exhaust valve if anything has pressure pushing or drawing it closed and the valve is lighter. On my digital InterComp spring tester the seat pressures on a new set of springs will range from 147-157 lbs typically @ 1.800" and 380-390 lbs @ 1.200" open pressure."

Dave Bisschop

My comments ...

No matter what brand just remember never trust catalog stated pressures, they can and do vary. Test them at your intended installed height with the retainers you plan to use.

And very important springs can lose pressure after run in and over time.

Information provided in this post does not represent a product endorsement. And unless specified it is not based on personal experience and is offered for general interest only.




Edited by - Steve C. on 20 Dec 2019 4:40:03 PM
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DanM
Cochise

230 Posts

Posted - 27 Dec 2019 :  10:14:45 AM  Show Profile  Reply with Quote
Tom (et al.)

I'm getting the rotating assembly from Butler racing. I reviewed every component including the bearings. The person I spoke with (name written down elsewhere) said the crank is a race grind with larger radius fillets thus requiring the narrower bearings as you suggested.

1 Month lead time as of last week. $2500

I paid my machinist for his work so far: engine disassembly, cleaning, magnaflux and inspection, measuring, light cylinder honing. $900

Budget: $2500 rotating assembly; $2000 heads; $2000 machinist and assembly; $1000 cam, lifters, timing set; $1000 my own time remove and install.

If I get 100,000 miles out of this engine that will be about 8 cents a mile. That's very close to the 8 cents per mile my 2013 Dodge Charger is losing in trade-in value.

-Dan
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Corncob2061
Crazy Horse

USA
628 Posts

Posted - 27 Dec 2019 :  5:27:57 PM  Show Profile  Reply with Quote
Dan I see you budgeted $2k for heads. Did you end up going a different direction than heads from SD performance? Jay
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tjs44
Crazy Horse

USA
659 Posts

Posted - 27 Dec 2019 :  5:54:58 PM  Show Profile  Reply with Quote
Dan,have your machinist check the cam tunnel.Been hearing of quite a few bearing failures lately.The cam can spin super free with no spring pressure on it but it only takes 1 thou to loose a cam bearing.My shop has had 3 blocks in the last 90 days with that issue.One was mine.Tom
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DanM
Cochise

230 Posts

Posted - 03 Jan 2020 :  11:12:42 AM  Show Profile  Reply with Quote
Jay,

SD is doing the heads. #96, to be ported to 260 cfm at 0.600". Same porting, springs, valves, and everything he has already programmed in his CNC. Same ole' same ole' (260 cfm at 0.600" and 1.800" installed height springs.)

Tom, what specifically should I have him check? He has already checked the cam tunnel and said it looks good. Same with the crank bearing saddles.
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tjs44
Crazy Horse

USA
659 Posts

Posted - 03 Jan 2020 :  7:32:54 PM  Show Profile  Reply with Quote
Have him blue the bearing tunnel and run his boring bar through it.I saw my tunnel,it had a tight spot in one number 1 and number 4.Also get a set of grooved cam bearings from Luhn performance.You wont regret it.My cam when when put in the fresh block would spin free with 2 fingers,when the load got on it from the springs it must have lost a touch of clearance.We found some trash in the filter,my machine shop and myself did not like it and took the engine down and found a issue with the #4 bearing.Saw NO sign with any of the 29 pulls on the dyno.I think part of it was the builder want 20-50 breakin oil.I think the low RPM starting(2000) pulls on the dyno did not have enough oil flo.NEVER had a pressure issue.I wont be using 20-50 again!Tom
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Steve C.
Chief PONTIAC

2125 Posts

Posted - 04 Jan 2020 :  05:19:14 AM  Show Profile  Reply with Quote
When I was dealing with Mark at Luhn Performance he told me that he had conversations with both Mahle and Dura-Bond engineers and he mentioned they tend to shy away from 20W-50 oil in street cars. They would prefer 10W30 or 10W40. At the time I did not ask Mark and he did not offer a specific reason why, and I don't remember if it was related to bearing clearances or piston rings, or both. I was going to tear down my engine and replace both bearings and rings and mentioned that to Mark in conversation, thus the specific companies he mentioned. It was just a passing comment when he asked me what weight oil I was using. For the most part I've always used 10W30 oil.

A link if interested in his bearings:
http://www.luhnperformance.com/pontiac.html
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DanM
Cochise

230 Posts

Posted - 17 Jan 2020 :  10:37:46 AM  Show Profile  Reply with Quote
Well it appears SD Performance is out of business or something. They don't answer the phone anymore. It's been a week of messages. The web site is dead.

I'm in for $1000 deposit.

My previous machinist, Jim Lehart, is retired and his shop closed down recently.

My plan B is to get my head repaired by Indy. I just spoke to them. $500 for the work. Plus shipping. 10 day turn around.

If that works then I'll use Dave Bisschop's recipe and have my local shop do the rest of the work on the heads. Probably cheaper anyway since I already paid Jim Lehart to port them years ago.

sigh.
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Corncob2061
Crazy Horse

USA
628 Posts

Posted - 17 Jan 2020 :  4:41:22 PM  Show Profile  Reply with Quote
SD performance is mostly a one man show these days. You almost need a spare engine to run while they work on stuff at a lot of these popular shops. If you can stand too wait I have no doubt that Dave will come through. I have heard of some pretty long waits.

A 10 day turn around to fix a cracked heads for 500 does not sound bad either. Jay

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DanM
Cochise

230 Posts

Posted - 21 Jan 2020 :  10:13:44 AM  Show Profile  Reply with Quote
I emailed Dave. He replied the same day. All is well. Indeed it's a one man shop and half a part-time gal in the office.
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