Rpms??

[JET-O-VATOR]

Ok guys sorry im asking so many questions but anyways....
how high can i safely take my motor? its pretty much stock with an rv cam.. i havent taken it above 4000 but she feels like she wants to go more......

[riverbound]

Just floor it and keep aneye on your guages. You will never know until you try it.

[BrendellaJet]

Do you know who built it? If the bottom end on that olds is stock, Id be extra careful with it. You can take it higher than 4k, but without any mods to the motor you'll drain that pan in a hurry and fry your bottom end. Id say you can go up to 4500 safely. Keep an eye on those gauges and you should be fine. Monitor your oil pressure real close. Make sure your plumbing is up to snuff too, olds like to put a little water in the pan.

[Petrofied]

4500 is safe, If the motor has cast pistons (stock) they like to break at the wristpins on the Olds motor. With the Olds is all about torque not rpm so we use a AA impeller to hold rpms down a bit. :)

[Back Forty]

I can vouch for 4500 rpms all day. I will assume mine still has cast pistons. I think my oil return holes have been opened up after a visual inspection. Previous owner rebuild. Stock pan.

[CrdStang]

Since we're taking about Olds stuff, anyone care to venture a guess what this setup would turn an AA impeller?
455 .060 over (468ci)
Crower Compu-Pro cam 274/281 total, 210/220 @ .050", .461/.486" lift
GA heads, Stock intake, Quadra-Jet, Logs.
I'm told the Compression is around 10:1
Any ideas?

[Wally_Gator]

Originally posted by CrdStang
Since we're taking about Olds stuff, anyone care to venture a guess what this setup would turn an AA impeller?
455 .060 over (468ci)
Crower Compu-Pro cam 274/281 total, 210/220 @ .050", .461/.486" lift
GA heads, Stock intake, Quadra-Jet, Logs.
I'm told the Compression is around 10:1
Any ideas?
Just a guess, I would say around 4900 rpms.
But it sounds like you have good parts in the motor, but you left out one of the biggest restrictions of the olds motors. None of the Olds heads flowed very well, with all of the HP parts in the bottom end and the valve train, these heads did not like to flow very well.
Was the oil system addressed in the motor?

[GM Killer]

Take the motor as high as it will go and see what it is first. It might only go 4500 or so. If it is a low rpm like that, then not much to worry about.

[CrdStang]

The engine sat for 5+ years before I bought the boat. It'd just been rebuilt, but wasn't completely covered; got some water in, the cam, couple valve seats and cylinders rusted. What I thought would be a drop in ended up costing me a bunch in machine work, new bearings/gaskets/cam.
Still putting the engine together, so far it only has the oil restrictors behind the main bearings. I'm thinking I'll put restricted pushrods in it too. It has the high-volume oil pump so I'm deffinately concerned about all the oil ending up in the valve covers. I'm planning to modify the stock pan by extending the sump all the way forward, but that'll probably be about it for oiling fixes.

[stillgoin]

have same thing...455 stock as I know it except RV cam...typically getting around 4250-4300 rpms. hoping to get a season or two in before switching to BBC. I just hear too many hems and hahs when you say 455. Guys have me worried its gonna blow every time I go to lake.
Stillgoin

[Joe B]

Jet-O-Vator
I run my 455 4700 all day long but I am thinking about switching to an Aggressor "A" to lower the rpms a bit.
CrdStang,
I think with that set up you will be lucky to turn the AA 4000-4100.
I have:
455 .060 over
290/300 total with 499/512 lift-advanced 4 degrees
10:1
Edelbrock 750 marine with torker 455
C heads
I turn the Berkely A 4700, 4800 on a good day. Duane at HTP and Ted from CBM both told me I did not have enough engine for the Berkely AA.
joe

[Back Forty]

Mine is a AA according to the stamping on the impellor but I think the pump guy cut it to work with the engine. I'm not sure anyway.:confused:

[CrdStang]

Isn't an Aggressor A supposed to be about the same as a Berk AA? Mine's an Aggressor A.

[Joe B]

Crdstang,
I was told the Agressor A would lower my rpms around 200. I believe the Berkely AA would lower them 500.
joe