Dry Sump vs external pump vs wet with accusump + block choice

[Chris]

I know its been posted on here and i have read the other threads etc however i had some more questions and thought easier to start a fresh one vs reopening an old one.

So my current dilemma:

I have a couple of options for blocks to base my build on (11:1 9.2 deck SVO block, basically a nascar esque build with 3.45" crank and 6.3" rods running small port, small chamber Yates C3 restrictor plate heads). The car will be 95% road use car but will be spun to 8k rpm when i feel like it and can put the power down.

-One is a rare siamese wet sump A351 block, at 4.060 with large amount of meat left in it but one sleeve. 2.749 cleveland mains. (pre 85 casting date)
-The other are non siamese G351 dry sump blocks (handful of options varying between 302 mains converted block with 55mm cam bores to 2.749 mains with normal or 55mm cam bores.
All blocks are either .040 or .060 over but sonic checked and good for boring to 0.080). (post '85 but pre '92 casting dates). 302 mains is preferable due to crank/rod options and less rotational friction and heat etc at higher rpm, but that block is 0.066 over fully machined ready to go.

Obviously i know dry sump is the best but it costs more however there are a lot of v good used dry sump systems that you can get for a good price.
So what i've costed below doesn't actually come up hugely different price wise.

Wet sump setup :
Pan - $350-450 w/ windage tray, crank scraper (if bought new)
Pickup - $80
Pump - $150 (precision pump)
Possibly oil cooler set up - $250?
Shafts and ARP bolts etc - $60
Accusump - $600

So say $1250-1500 if everything bought new.

External pump wet sump:
Pan - $450 (if bought new)
Pump - $3-400 (used)
Belts/Crank pulley/Pipework - $300 +/-
Accusump - $600

So say maybe $1600.

Dry Sump:
Can get 4 stage kits complete from race team etc for $600-$2000 with pan if they have a suitable one for 4 stage system with tank. Would only purchase non failed engine kits.
Naturally would have to go through, check the pump and fully clean everything etc so budget for that.
Would allow lower mounting of engine if possible (will be using either ZF/quaife or 930 porsche box) to compensate for taller deck and exhaust port height.


Obviously the dry sump is the best hands down and it will pull crankcase vacuum, its just big and complicated and would be a used system. . . . .
Naturally the decision affects which block i go for and they have their advantages and disadvantages for each one. Bit of an essay but hopefully you can see my dilemma of which direction to go in.

Would love to know your educated thoughts.

 

[Terry Oxandale]

I was extremely fortunate to be in the right place at the right time to purchase a used Dailey Engineering outfit. I'm using the 930 T/A, so yes, the engine cannot utilize a wet sump if you really want to do it right (CG, half-shaft angles, etc). I have never regretted the dry sump even though it was my very first. It has been an extremely forgiving component, allows the engine height appearance to be aligned with what is expected for these kinds of cars, and I never worry about lubrication.
When I received my set-up, I dismantled the pump to inspect the lobes and walls, and even with some minor (my interpretation) galling (dressed these carefully), the assembly provides ample pressure and flow. With the dry-sump's complexity, you also get it's flexibility in choosing gear ratios for flow/pressure, adjusting what you want for vacuum, and of course, the larger capacity oil reserve.

 

[Chris]

I was extremely fortunate to be in the right place at the right time to purchase a used Dailey Engineering outfit. I'm using the 930 T/A, so yes, the engine cannot utilize a wet sump if you really want to do it right (CG, half-shaft angles, etc). I have never regretted the dry sump even though it was my very first. It has been an extremely forgiving component, allows the engine height appearance to be aligned with what is expected for these kinds of cars, and I never worry about lubrication.
When I received my set-up, I dismantled the pump to inspect the lobes and walls, and even with some minor (my interpretation) galling (dressed these carefully), the assembly provides ample pressure and flow. With the dry-sump's complexity, you also get it's flexibility in choosing gear ratios for flow/pressure, adjusting what you want for vacuum, and of course, the larger capacity oil reserve.

Ah you swine, did you get the billet sump direct pump Dailey setup? if so that is simply beautiful but way out of my price range even used!
Do you know if the inverted 930 box sits higher than ZF?

 

[Terry Oxandale]

Yes, direct bolt to pan. I do not know the ZF answer. I do know that with a short wet sump on my LS block (apples to orange comparison, I know), that with the half-shafts horizontal (but they are angled forward), the wet-sump pan actually lifted the rear of the car by 1/2" from the normal ride height (yes, the pan was contacting the floor, holding the car up slightly). The lowest portion of the car at this point is right at about the 930 bell-housing, and that is with about 1" of the adapter plate removed, leaving just enough to protect, per se, the bellhousing from anything on the road. So in essence, the transaxle ground clearance dictates the height of everything else at that point.

 

[Jac Mac]

If your even thinking of the Dailey dry sump Pan for your Ford engine, please spend an hour or so scrolling thru Russ Noble's build thread. Dailey might make good stuff for chev's etc, but Russ found he was being used as an experiment and the Pan was useless. From my own point of view I regard Accusumps as a buffer to allow you time to get your wallet out to pay for the dry sump you really need if your generating enough 'g'. cheers

 

[Chris]

If your even thinking of the Dailey dry sump Pan for your Ford engine, please spend an hour or so scrolling thru Russ Noble's build thread. Dailey might make good stuff for chev's etc, but Russ found he was being used as an experiment and the Pan was useless. From my own point of view I regard Accusumps as a buffer to allow you time to get your wallet out to pay for the dry sump you really need if your generating enough 'g'. cheers

i have to admit it’s not even on my radar due to price but I’ll have to have a read anyway as that sounds interesting!
The buffer quip made me chuckle I have to admit.

I severely doubt I’ll be pulling enough G to warrant a dry sump it just came down to being an option related to block choice.

Spoke to the gent again who has the 302 mains converted G351 block tonight and he believed it sonic’d to over .200 left at lowest point which surprised me greatly as the block is 0.066over! Is going to get me pics when he can of the results (the seller is a renowned pikes peak builder and racer so I’d like to think he wouldn’t be fibbing). That block is currently my no.1 choice so it would have to be dry or external pump if I buy it. Of which I may as well go dry for its advantages.

 

[Jac Mac]

i have to admit it’s not even on my radar due to price but I’ll have to have a read anyway as that sounds interesting!
The buffer quip made me chuckle I have to admit.

I severely doubt I’ll be pulling enough G to warrant a dry sump it just came down to being an option related to block choice.

Spoke to the gent again who has the 302 mains converted G351 block tonight and he believed it sonic’d to over .200 left at lowest point which surprised me greatly as the block is 0.066over! Is going to get me pics when he can of the results (the seller is a renowned pikes peak builder and racer so I’d like to think he wouldn’t be fibbing). That block is currently my no.1 choice so it would have to be dry or external pump if I buy it. Of which I may as well go dry for its advantages.

Hmm, sounds like one or both of the engines Jack Ondrack was thinking of buying, but that was several years ago. The PP racer wouldnt be Dennis ( cant remember how to spell the name) was Vashovitz or something like that?...0.066 would only be .033 on side of each bore

 

[Chris]

Hmm, sounds like one or both of the engines Jack Ondrack was thinking of buying, but that was several years ago. The PP racer wouldnt be Dennis ( cant remember how to spell the name) was Vashovitz or something like that?...0.066 would only be .033 on side of each bore

he’s had the blocks sat around for a while indeed and you’re not far off with the name!
he doesn’t advertise what he has so just sells it when people ask!

 

[DaveC]

To reiterate what was said above... As far as dropping the engine lower with the dry sump, on my LS/Porsche (g96) setup with the KEP adapter, the adapter and bellhousing sit significantly low enough that a dry sump pan would not allow me to drop the drivetrain any lower. Something to look into with your setup, as the gearbox is inverted.

 

[Randy V]

Never been a fan of oil accumulators for anything other than providing oil supply at start-up.
Why?
Because they discharge all that oil when called upon (high G maneuvers).
Once that event has concluded, the driver is generally hard on the throttle.
Meanwhile a good portion of the now available oil volume from the pump is being diverted from the engines bearings in order to refill the accumulator.
Better oil control through a properly designed sump and pickup would be the preferred low cost improvement.
Else - of course - there is the dry-sump system and its attendant complexity and expense..

 

[Chris]

Never been a fan of oil accumulators for anything other than providing oil supply at start-up.
Why?
Because they discharge all that oil when called upon (high G maneuvers).
Once that event has concluded, the driver is generally hard on the throttle.
Meanwhile a good portion of the now available oil volume from the pump is being diverted from the engines bearings in order to refill the accumulator.
Better oil control through a properly designed sump and pickup would be the preferred low cost improvement.
Else - of course - there is the dry-sump system and its attendant complexity and expense..

Is a valid point but I know they have different types of valves for refilling.
One for ‘race’ that refills quickly when pressure above 35psi and another that refills slower.