Olds 455 RPM questions?

[maxwedge]

Ok so since nobody, incuding myself, really believes that my POS Sidewinder really is hitting the 67MPH that we GPS'd it at the other day. I want to re-test this weekend with a different GPS (okay so mostly I just want to go drive around the lake really fast). But in the interest of science...
I'll admit I don't know jack about GPS's. I thought they were all pretty accurate, but now It's really bothering me more that thing was reading 80 when the the speedo in my truck said 75. I had chalked it up to crappy Ford f150 speedo calibration, but now I'm not so sure. Can anyone reccomend a good GPS in the $100-300 range? I think I need to buy one.
Anyway, I fixed my tach today (broken wire connector), so now I can actullly see how close I am to scattering Olds parts into the lake. Just wondering who can tell me what a "safe" RPM is to run this thing. I know it's bad to run WOT run extended periods, but just what is to long or too fast. Contrary to what the Previous owner claims, I think it's safe to assume that it's basically a mostly stock 1976 Hardin/Olds 455 with the exception of an oil cooler,dual remote filters, maybe a mild cam, and a recent half-ass rebuild. I have no reason to believe this guy knew enough to add oil restricers, or anything like that and it has the stock pan also, with no external drainback lines. Maybe he wanted a stealth look, but I doubt it with that Mr Gasket scoop. :smile:

[Red Horse]

5500 Tops and not for very long.
I have a 69 Weimann custom with a 455 Olds, eldebrock system matched carb, intake and cam, place diverter, and blueprinted pump my Marine performace designs and the best I have EVER run was 63. And that was on Mohave (river) below Hoover dam on a cool day in cold water going WITH the current. Most of the time is 55-60 MPH. So yeah 67 is a little hard to believe.

[Taylorman]

I keep my 455 below 5000. Best speed so far is 67.5 on GPs at 4900 rpms. My gps is a nordskog in dash gps speedometer.

[malcolm]

This year we tried two yellow Garmins in the same boat. Mine read around 1 mph slower than the other one. But it does read dead on with my car's speedo (98 Malibu).
I'll second the 5500 (but 5000 is safer), and I've heard many guys say as little as 30 seconds might be too long. It all depends on the build. I'd say you are better off then most having an oil cooler.

[HotDogz]

With a stock rebuild, would not recommend more than 5000 at all because of the stock rocker assembly (all aluminum) being a critical weak link as they are not designed for high revs. With no restrictors in my engine, I spun my main bearings in after 2 high speed 20-30 sec passes. Sucked all the oil out of a 10qt pan and pushed it out of my valve covers. Stock valve train showed wear variances .010 to .035 variance on each VALVE. Also would not recommend anything over 5000rpms unless your assembly has been internally balanced.

[HotDogz]

Also Garmin Rhino 120 kicks booty. Complete trip computer with GSMR radio.

[maxwedge]

5500RPM! Holy crap! I'd be suprised to see this thing crack 4500 RPM at all, let alone without coming apart. But then again, I have been judging engine RPMs by using my finely calibrated ass until now.
Also I've been researching various GPS's on the web and I can't believe how cheap these things have gotten in the few years since I looked last. Tons more features too. Kind of overwhelming. Now I just need to justify the expense to the w(Bit%$y today)ife. Did I spell that right?

[Taylorman]

5500RPM! Holy crap! I'd be suprised to see this thing crack 4500 RPM at all, let alone without coming apart. But then again, I have been judging engine RPMs by using my finely calibrated ass until now.
Also I've been researching various GPS's on the web and I can't believe how cheap these things have gotten in the few years since I looked last. Tons more features too. Kind of overwhelming. Now I just need to justify the expense to the w(Bit%$y today)ife. Did I spell that right?
If you cant get your wife to let you buy a GPS, i have some advice for you, sell your jet boat.

[maxwedge]

If you cant get your wife to let you buy a GPS, i have some advice for you, sell your jet boat.
I'd rather sell my wife (just kidding honey). Besides I'm heading to Best Buy now to see what they've got. All it took was some major BS about never getting lost on road trips again, and some...uh...well.. she seems happy now anyway.

[moneysucker]

I'd rather sell my wife (just kidding honey). Besides I'm heading to Best Buy now to see what they've got. All it took was some major BS about never getting lost on road trips again, and some...uh...well.. she seems happy now anyway.
I get lost on road trips with directions. I think it has something to do with I don't listen. I bought my GPS at target it is the garmin yellow one. I would get another one too especially since I found a billet GPS mount for it. One mounted in the boat to keep it from falling in the bildge and one on my quad so when our group leader gets too far off track I can tell him where we should be heading.

[Squirtcha?]

I've got the etrex (yellow one) too. Where'd ya find the billet mount MS? If I could find one of those mounts for the handheld, that'd be the ticket. Never can figure out a place to set it, tie it down, lean it, etc. etc.
Found out that Rex carries the Autometer Pro-Comp head end that'll match the rest of my gauges, and all you have to do is buy the receiver/antennae box to hook it up. I'm short of dash room though, and that would mean buying one of those Horn looking gauge pod dealies to mount on the deck.
http://shopping.rexmar.com/Merchant2/graphics/00000001/AUT200836-33.jpg
http://shopping.rexmar.com/Merchant2/graphics/00000001/391111.jpg
Incidently so we're not totally off topic here. My Etrex is dead on with my truck's speedometer. It's a $99 unit with the most basic of functions. It does have max speed memory which was the most important thing to me since I bought it just for a boat speedo.

[Taylorman]

Dan,
I just bought one of these and love it. It has a gps, tachometer, compass and voltmeter all on one gauge. Unchained also has one and likes it.
http://www.nordskogperformance.net/products/marine/gps/detail/hgd200.htm
http://www2.***boat.com/forums/showthread.php?t=74089&highlight=gps+speedometer
I replaced my tach with it and am about to remove my volt gauge and put in a fuel pressure gauge.
http://www2.***boat.com/image_center/data/500/161DCP_5623.JPG

[Squirtcha?]

I saw your post regarding the gps speedo a while back. On your boat, with the other white gauges, it looks great. On mine it wouldn't match at all. I've got all silver Autometer Procomp gauges in my dash. If they came out with a silver faced one, I'd definitely consider it. Hate to put it all on a "looks" thing, but I guess that's where I'm at.
http://www.jetheaven.us/photopost/data/500/19gauges_cropped_II.jpg
Yours has some really neat features that I like. The LCD seven segment readout, rather than trying to see the little lines between the numbers on the needle type gauge would be nice.
Not entirely sure how much I'd use the other features. I'd like to be able to see both speed and tach simultaneoulsy. Do you have to switch back n forth? As for the compass..........most the places I've boated, you couldn't get lost if you tried.

[Taylorman]

I hear you on the looks thing. They make them in white black and silver. Yes, they have a small toggle switch you have to press to switch from speed to tach to compass to volts.

[Squirtcha?]

What? They make em in silver? I might have to re-think this.....

[n8dawg]

I'm running a 455 olds with a tunnel ram set up and 2-450cfm holleys, jacuzzi jet wj NO PLACE DIVERTER in my miller. With a max speed of 65mph (magellan explorist gps reciever) and thats with 105 octane, no baffles,and running down river. I bought the boat with the intensions of building a chevy for it. So far this olds has held up to everything I can dish out. I didn't build the motor but have torn the top end off (blew out head gaskets after turning up the h20 pressure) come to find a nice set of forged flat top pistons, "K" heads port matched to intake, and roller tip rocker arms. My top speed is 65 @ 5100 rpms thats all she has in her. I let a friend of mine drive it with out telling him the do's and don't's and for about a good minute or so he ran flat out. I was building up the chevy motor in my mind the entire time he was driving! Didn't blow. I've been out at the river hanging out till sunset then realize how far I have to drive and I'll cruz at 3500-4000rpms for about 20 minutes. She still hasn't blown! But wouldn't mine tearing it down and freshning it up a bit. Winter projects: rebuild motor and add on a place diverter, with pump rebuild, if it need one.
thats my .02
late
nate

[1975sleekcraft]

I mashed my pedal down.I don't know top speed but I do know 5300 rpm's for
obout 10 minuts.this might be crazy but it was really fun! I am running just under 10-1 compresion,oil restrictors,arp bolts,slotted big end of my rods,and
a 10 qt oil pan.this winter i'm going to put in the oil cooler(someone told me too).the oil pressure never dropped.

[maxwedge]

Taylorman]Dan,
I just bought one of these and love it. It has a gps, tachometer, compass and voltmeter all on one gauge. Unchained also has one and likes it.
Yeah I like those too. I especially like the way that the one Unchained has makes that awesome twin turbo, rat motor sound. Does that sound come with the unit? Because if so, I'm getting one. Otherwise, I'm going to buy a portable one for now so I can use it elsewhere. I'm guessing it's a real pain in the ass to drag an old Sidewinder around, just for the GPS, when you are hiking in the woods.
I still haven't decided which one I want, but I'm going to do some more research tommorow. Also It's really damn cold here now (45), so now I'm not even sure I will go to the lake this weekend. GRRR :cry: It was 90 Mon-Wed, guess I got used to it. I hate IL weather. If nothing else, I'm going GPS shopping.

[moneysucker]

I've got the etrex (yellow one) too. Where'd ya find the billet mount MS? If I could find one of those mounts for the handheld, that'd be the ticket. Never can figure out a place to set it, tie it down, lean it, etc. etc.
Found out that Rex carries the Autometer Pro-Comp head end that'll match the rest of my gauges, and all you have to do is buy the receiver/antennae box to hook it up. I'm short of dash room though, and that would mean buying one of those Horn looking gauge pod dealies to mount on the deck.
http://shopping.rexmar.com/Merchant2/graphics/00000001/AUT200836-33.jpg
http://shopping.rexmar.com/Merchant2/graphics/00000001/391111.jpg
Incidently so we're not totally off topic here. My Etrex is dead on with my truck's speedometer. It's a $99 unit with the most basic of functions. It does have max speed memory which was the most important thing to me since I bought it just for a boat speedo.
I don't have a Pic of the Billet mount in my comp but will get one tomorrow. I got it from Fiber Tech a dune buggy place out here in santee, CA (San Diego) They have no web site but here is their contact info. I believe my mount was $48 or so.
Yellow Pages - Listings
Fibertech-Carquest
10809 Prospect Avenue, Santee, CA 92071
(619) 448-0221
If you don't remember the Moneysucker does 100 thread, they were busting my balls for having it zip tied to the steering wheel (That is right CS 19 with Blue zip ties)
As for the top RPM For an olds, I had one built and was running 6000 rpm for at least a minute or 2 (maybe longer it has been a long time) racing a friend with a chevy until there was a loud knocking. The top of #1 broke off from the wrist pin up. I would say a 5500 chip in the msd box is more than enough. More is not a good idea. Of course I do know a few people running NOS in 455s in jet boats and living. (OK, 1 and one that used to)

[jetbtkng]

my 74 tahitti 18ft did 100mph 6100 rpm 114octane 455 bored to 473 12to 1 compression joe madello built it for me

[kcsteck]

if you have so much $$ in this supposedly 100MPH Tahiti, youd think you could spell the guys name right. ITS Mondello bro not Madello the beer. LOL
100 mph Tahiti now thats funny! I have Tahiti and I know how heavy they are.
your killin me

[Wet Dream]

if you have so much $$ in this supposedly 100MPH Tahiti, youd think you could spell the guys name right. ITS Mondello bro
DING DING DING!!!!
There's the post of the day. If you spent anything close to the $15,000 that Mondello wants for a motor like that, you'd never forget his name. ;)

[maxwedge]

DING DING DING!!!!
There's the post of the day. If you spent anything close to the $15,000 that Mondello wants for a motor like that, you'd never forget his name. ;)
You guys just aren't listening right. This is Joe Madello. Totaly differnt guy. He works out of a thatched roof shed in Paraguay and does way better work than the the famous Joe Mondello, and it's way cheaper too. The reason you never heard of him is because his shop is really a top secret govenment facillity where they do research on old Tahiti jet boats that they use to transport alliens across the pacific ocean in the dead of night. You have to be a jedi knight to enter the secret sacred cylinder head forest....where you can buy 67mph Sidewinder motors and 100MPH Tahitis...TEEEHEHAHA. I would tell you but then it wouldn't be special anymore. :rollside:

[Wet Dream]

The natives are restless. :D :D