1958 GMC 100 Truck

[adnick]

Have quite a bit of history with BBC engines, not up to date by any means but there’s probably still some useful stuff….besides common intake, carb, FI , cam, piston bore and stroke kind of stuff, common stuff, here’s a couple of my recommendations:

The way the stock BB oiling system works it’s easy to “pool” the oil in hard corners and/or hard braking, which can cause a momentary drop in oil pressure, adding an oil accumulator is a great idea and not that costly, plus they prevent “dry”starts, when plumbing one in I’d add a remote oil filter.

Probably the biggest performance gain I ever achieved was having my heads professionally flowed, of course one has to provide the extra fuel for such, but hey

Also extra HP always equals extra heat so don’t skimp on the cooling 👍

 

[gortnipper]

1955-59 GMC Chevrolet Truck Radio Chevy Apache Pickup Stereo AUX AM FM | eBay Pardon Our Interruption...

 

[MrEd]

Andy is correct, a lot of motors die from oiling issues.
If you're spending on nice internal parts and doing a proper build, factor in the correct oil pan for the application along with well designed windage control. If done correctly no need for the added complexity of the acusump. No offence but they are just a bandaid for a poor oil sump configuration.
A well designed windage tray and crank scraper is also some free horse power on the top end because the crankshaft no longer has a mass of oil spinning with it.

 

[adnick]

Won’t argue with a well designed oil pan, scrapper, and oil pump that doesn’t drop its sump

For BBC’s I’ve just found accumulators and easy extra insurance policy…few extra quarts of oil and constant oil pressure (even before starting)

 

[Dr Morbius]

I’m looking for the truck of my dreams, the 1937 Studebaker Coupe Express by Designer Raymond Loewy………….now that’s a truck!

 

[GuyK]

Andy is correct, a lot of motors die from oiling issues.
If you're spending on nice internal parts and doing a proper build, factor in the correct oil pan for the application along with well designed windage control. If done correctly no need for the added complexity of the acusump. No offence but they are just a bandaid for a poor oil sump configuration.
A well designed windage tray and crank scraper is also some free horse power on the top end because the crankshaft no longer has a mass of oil spinning with it.

I always thought the reason for using an oil accumulator was to pre-oil the motor before cranking it to eliminate dry starts. If it's to band-aid oiling for hard cornering and braking, then one is better off with a dry sump system, and one would still have to use the accumulator. Then you can drop the motor in the chassis to get CG lower also. But these ALSO require windage trays and crank scrapers and knife-edged cranks, and are very complex and veeery expensive. Special baffled shallow pan. multi-stage scavenge pump and lines (from each section of the pan) to large remote oil tank, then another pressure pump and lines to lubricate the motor... TOTALLY overkill for even spirited street use. Totally overkill for just about anything less than Nascar Cup series or something like vintage Can-Am racing. There are a few benefits to them besides lower CG as well. Here's a decent explanation:

 

[MrEd]

Dry sump is way overkill for a street car.
I have dealt them and they have a lot of headaches that come with them not to mention the expense. They do have some cool factor.

 

[GuyK]

Dry sump is way overkill for a street car.
I have dealt them and they have a lot of headaches that come with them not to mention the expense. They do have some cool factor.

TOTALLY agree. But they have been used from the factory for production cars on occasion. IIRC, Porsche used them on all their air-cooled flat 6 engines, I think Chevy used one on the LS-7 Z-06 Corvettes for awhile, and there are a number of others I can't think of off top of my head.

 

[adnick]

I always thought the reason for using an oil accumulator was to pre-oil the motor before cranking it to eliminate dry starts. If it's to band-aid oiling for hard cornering and braking, then one is better off with a dry sump system, and one would still have to use the accumulator. Then you can drop the motor in the chassis to get CG lower also. But these ALSO require windage trays and crank scrapers and knife-edged cranks, and are very complex and veeery expensive. Special baffled shallow pan. multi-stage scavenge pump and lines (from each section of the pan) to large remote oil tank, then another pressure pump and lines to lubricate the motor... TOTALLY overkill for even spirited street use. Totally overkill for just about anything less than Nascar Cup series or something like vintage Can-Am racing. There are a few benefits to them besides lower CG as well. Here's a decent explanation:

The drop in oil pressure in those situations is extremely momentary so the accumulator just maintains, but under a load momentary can be catastrophic

Ed obviously has a lifetime of experience and is up to date, so I’d listen to him

My last serious BBC build was back in the days when “Big Red” dominated the Silver State Classic …..

 

[GuyK]

The drop in oil pressure in those situations is extremely momentary so the accumulator just maintains, but under a load momentary can be catastrophic

Ed obviously has a lifetime of experience and is up to date, so I’d listen to him

My last serious BBC build was back in the days when “Big Red” dominated the Silver State Classic …..

Yeah, MrEd has a LOT more experience, and is up to date. I've just never heard of an accumulator being used in this manner. I've built a couple motors myself, but they've only been mostly-streetable LA series Mopars.

I remember Big Red back then. They were using a Lingenfelter built Donovan(?) aluminum big block Chev. One Bad Ass car.

 

[MrEd]

The issue with accumulators or Acusump is that right after they dump you have a too much oil in crankcase.
Then you get it pushed to all the places it doesn't need to be. Fills the heads and often blows out valve cover vents, or pushes past the rings which in turn causes a lot of smoke 🙂.
Worst part is those amounts of oil in the combustion process causes detonation.
Sorry for the technical rambling 😔

And late 60's early 70's Mopars... got love em 😎

 

[GuyK]

Mine's mid 60's. 1965 Barracuda. Originally a 273 auto that I converted to 4 speed. Currently a 0.030 (maybe 0.040, I don't remember for certain) over 318 with a forged crank, big cam and some compression, T/A casting heads with a little bit of porting done to them, and a 340-6bbl intake. Yes, it's way too much carb, and yes it looks great.

 

[MrEd]

Mine's mid 60's. 1965 Barracuda. Originally a 273 auto that I converted to 4 speed. Currently a 0.030 (maybe 0.040, I don't remember for certain) over 318 with a forged crank, big cam and some compression, T/A casting heads with a little bit of porting done to them, and a 340-6bbl intake. Yes, it's way too much carb, and yes it looks great.

Post some photos in the garage section.
Sadly all my pre 2011 photos are lost.
No photos of 340 shakerhood Cuda, or any other cool cars and racing stuff.
A friend had a 67 Baracuda S model when were 18 or 19.

 

[analogadikt]

With the BHP of 500 or 700, would this truck be having hydrodynamic or electromagnetic retarders ?

Regards,

 

[adnick]

The issue with accumulators or Acusump is that right after they dump you have a too much oil in crankcase.
Then you get it pushed to all the places it doesn't need to be. Fills the heads and often blows out valve cover vents, or pushes past the rings which in turn causes a lot of smoke 🙂.
Worst part is those amounts of oil in the combustion process causes detonation.
Sorry for the technical rambling 😔

And late 60's early 70's Mopars... got

Never experienced that, but a fixing some oil leaks is much better than picking up motor parts

 

[Audionut]

A few updates; the front grill was put back in, but that has raised a question as to the originality of it (more on that later). The frame shortening has commenced, and I also picked up a short bed (which I’ll not post for now, due to the wonderful clown car paint job).

When deciphering the series number, it told me that I have a 1/2 ton, V8, from the Oakland plant. Model S, which covered the ‘58-‘59 year. Mine was title as a ‘58 so I adjusted the thread title accordingly. Flip kit is next, then onto suspension/breaks.

 

[MrEd]

Very interested in your frame shortening methods 🙂
Do you plan to smooth the welds on outside so the don't show and are reinforcing in any way?

 

[Audionut]

Very interested in your frame shortening methods 🙂
Do you plan to smooth the welds on outside so the don't show and are reinforcing in any way?

Yes indeed; smooth out the outside and stitch plate the insides.

Doing the C-notch too but a little unimpressed with the kit.
Also doing the flip kit.

 

[MrEd]

Not familiar with a flip kit.

 

[mhardy6647]

(which I’ll not post for now, due to the wonderful clown car paint job).

Dang. With that description, now I really want to see it! 🤦‍♂️