'84thunder

just curious to know if someone out there has ever thought of or actually done an engine swap, by taking out the old V6 or V8 and using a Cadillac Northstar V8?

88FormulaKiller

iTrader: (8)

ive had quite a few caddys with the northstar and my only advice/input is this..

-its gonna be kinda difficult since most are FWD

-- and... WHY? Northstars are notorious for the dreaded oil seal in the block, usually showing up right on schedule around 100K miles, that or a blown head gasket.... not ALL of them have those issues but i really feel its a game of roulette.

jensen73110

iTrader: (4)

IMO, a better route for 32v would be the LT5. Sure, pricier, but way more awesome.

'84thunder

just curious. thats all. i know people have done some crazy stuff with cars/motors combos and was just wondering.

formulakiller: so your pretty much saying the caddy engine is as dumb as the 400SBC with the super thin cylinder walls that dont have a cooling jacket in between and therefore cause cylinder wall problems at high temps, vs. a normal 350 block that doesnt share the cylinder walls and has a jacket in between them so the walls can be bored out safely without concern of damaged cylinder walls? i get it

'84thunder

i like ur style

midias

mmmmmm LT5

88FormulaKiller

iTrader: (8)

Absolutely

Yes, the LT5 is a pretty sick engine, very costly though.

'84thunder

song that comes to mind as i look at this photo...Jizz in My Pants - by Lonely Island.

zenish

i seem to remember that people doing swaps with the northstar used a modified v6 700r4.google it.

Tibo

iTrader: (15)

Show me a 400 sbc with an adequate CR, cooling fans and aluminum heads that has problems in a normal street/drag race/autocross. Any engine built or driven incorrectly will have problems.Aftermarket engineers can fix almost any problem....well almost.

Nobody uses a Northstar because there are no advantages to it over a LT/LS or hopped up SBC.

'84thunder

easy guys....im just asking if it has been done and if it would be any fun.

Tibo...the 400sbc is notorious for internal engine problems. the problem lies within the cylinders and walls. unlike a 350 there is no space in between the cylinders ( usually called a jacket) where the coolant flows. its one solid piece. therefore when you bore the cylinders of a 400sbc you are making the walls super thin and chancing a wall or 2 blowing in or piston problems. there is no even balance with the walls of a 400 vs a 350 where there is a jacket and the walls are not being shared.

Tibo

iTrader: (15)

Again, if there is a reasonable compression ratio (this is the ratio of the volume between the piston and cylinder head before and after a compression stroke), Adequate cooling fans (this helps cool the engine) and Aluminum heads (Aluminum has a higher heat capacity) the engine will do fine.

'84thunder

uhhh...aluminum does not have higher heat capacity and will always melt, warp, break, stop being worth anything vs. iron block. i know this...i have trickflow aftermarket heads (ALUMINUM) and have warped them twice because aluminum sucks for heat. doesnt matter how big/great/expensive your radiator is(the cooling system main part) ask any dragster about a 400sbc and they will tell you...yes they are great for power but they suck when they break and they break constantly, they will probably even tell you they have a stockpile of bare 400 blocks because they are poopy.

god i wish i could swear on here...but i cant.

sofakingdom

iTrader: (1)

On what planet???

This is typical NON-400 OWNER BS. The stuff you always hear from people who HAVE NEVER HAD ONE and just repeat the same hot-rod mythology lore endlessly without ever learning anything. Some of it is driven by the "sour grapes" mentality besides ("I can't find one so I'm just going to convince myself they aren't any good anyway") which just makes it even MORE annoying. If that's all you can say about them, best to keep your mouth shut and not remove all doubt.

/rant mode off

That said, NOT ONLY have I had NUMEROUS 400s over the years, BUT ALSO a N* car.

When I bought the car in question it already had the "head gasket" problem, which is REALLY a "block" problem. What REALLY happens is, the fine thread on the 11mm head bolt holes experiences dissimilar-metal corrosion, leading to failure of THE BLOCK. The head bolts pull out of it, taking the last remaining remains of the threads with them. You can replace head gaskets every day, and twice on Sundays just for good measure, and they will STILL fail.

The cure is steel inserts; preferably NOT TimeSerts such as the factory uses (a large OD but the same way-too-fine threads) but rather something with MUCH larger and coarser threads so the corrosion takes longer to have its effect.

The next thing that will happen is, the metallurgy of the head bolts in replacement sets is different from OE ones. The way they work is, think of them as being "springs" instead of "bolts"; you tighten them to yield, and their tension allows them to move as the aluminum expands and contracts. If you under-tighten them, they will not be "springy", and instead they will exert too much force on the block, breaking it in half. I have 2 such N* blocks sitting on my driveway at this very moment, split right below the bottom of head bolt hole threads all the way from accessory mounts to bell housing flange. I was an idiot and failed to learn my lesson, namely use the torque specs that came with the replacement sets and NOT the ones in the FSM. Clearly one of those cases where not only does the factory not know "best", but also, the replacement parts aren't even the same as the OE and therefore have tobe handled differently. Those of you who have tried to build a trans using the FSM instead of the most current ATSG manual will know what I'm talking about.

However, when they run right, they RIP. They're AMAZINGLY powerful and light. They have the same bolt pattern as the 60° 6-cyl which makes transplanting them simpler. The hardest thing about them is, the water pupm is at the same end as the bell housing (therefore up against the firewall in a longitudinal mount situation), and the air intake faces rearwards as well. But if you're willing to deal with those 2 fitment issues, it might not be a bad idea.

Given that there are HUNDREDS OF THOUSANDS of them in existence, compared to ABOUT 10 LT5s, they are a VASTLY better swap candidate for most people. It's ALWAYS cheeeeeeeeeper and eeeeeeeeeeezier to do a swap with something that's CHEEEEP and PLENTIFUL than something rare, "Vette", and overpriced. The LT5 swap is pure monkey-spank and crazy-talk for the vast majority of the real world.

However, I personally will pass on the N* opportunity, having already had more than my fill of them. Their shortcomings are more of a turn-off than their strong points.

'84thunder

sofaking...thanks for the input. i will pass this along.

Tom 400 CFI

Educate yourself before "passing anything along". You've embarrased yourself above by posting innaccurate rhetoric that you apparently "heard from dragsters" somewhere...while having no actual first hand experience. Sofakingdom is totally right. Re-read his post a few times, then stop spreading midinformation. When you have first hand experience...THEN post about that.

89_RS

Guess these modern all-aluminum LS engines are just time bombs waiting to go off then. Aluminum has a higher heat transfer rate than cast iron which requires a cooling system that can remove heat from the coolant faster. A properly cooled engine will function just fine, be it an all aluminum LS engine, a cast iron block/aluminum top end 350, or an all cast 400 SBC.

If you've warped your heads, me thinks you have a cooling problem. And, FWIW, cast iron will warp or fracture depending on bad you abuse the heads thermally. You sure that your water pump or fan ain't dead?

1ADan

iTrader: (4)

if you've got money, feel like being original, and can fab, go for it.

but once everything's said and done, you'd probably dump less money for a 5.3 (or similar) swap, have as good or better power, and have lots of help from others if something acts up

'84thunder

i have a Be Cool radiator (6 months old) and a 6 month oldVictor series water pump. my cooling system is more than adequate for my engine set up. but thank you for the idea

89_RS

How many cores in the radiator? What flow is the water pump? What is the core construction in the radiator? Whats the flow profile of the radiator? How much air can your fan move over the radiator? Are there any obstructions of air flow to the radiator that would limit how well the fan worked? When was the coolant system last flushed? Is there the proper amount of coolant in the system? Are there any obstructions/leaks in the flow path of the coolant?

The name of the game in cooling is how fast & how much heat energy your cooling system can extract. Just because you have a brand name radiator & water pump doesn't mean that its an adequate system. Theres a mile long list of questions on the coolant system alone that need to be answered.

Also, I find it hard to believe that your heads were the only thing that got damaged. If your engine got that hot (roughly 750*-800* F) your engine bearings would have fallen apart (they are lead based alloys that are fluropolymer coated), pushrods would have buckled, and you'd probably be missing parts of your pistons not to mention all your gaskets would have melted and started to run away like eggs in a skillet. Heck, the block may have even warped and you not know it.

There is something clearly wrong with your engines cooling system. The only other thing I can think of that might even be remotely possible is that you're running the engine in a way that produces above normal combustion chamber temps that cause the coolant to flash to steam, but you'd have at the bare minimum piston & valve damage as well as missing parts of the combustion chamber.

You've either got a problem with your cooling system or your putting way more heat into the coolant system than it can handle. I've melted down an engine before on the dyno stand trying to run it leaner & leaner (for the FSAE endurance part of the competition) and the line between safe operation & total engine failure was a .01% change in the unburned O2 content in the fuel. So before you go thinking aluminum engines aren't worth it even in the scrap value, solve the problem before throwing an engine and more money away.

'84thunder

nothing stock remains in my engine, except the block. the block has been inspected after each cylinder head mishap and all was good. all engine internals have been replaced and upgraded, forged crank, forged pistons and rings, push rods and all head internals are top of the line. the first time i broke my heads was during a burnout contest at a show, they were spraying my radiator to keep it cool. however my radiator was stock. after that...i got me a brand new Be Cool radiator http://www.summitracing.com/parts/BCI-61015/ and i realized my water pump was shot as well. so i got me nice new Edelbrock http://www.summitracing.com/parts/EDL-8827/. my cooling system is great. just must have had bad heads and bad luck

89_RS

What heads were they? What size fan? You can have the worlds greatest radiator, but it aint worth jack if the fan isn't up to the task. Also, how does the air flow get to the radiator? Something isn't adding up. You've got a good pump & radiator, but you're still not getting the heat out. Either you're fan isn't good enough or getting enough air to do its job properly or you're engine is running way too hot for your cooling system to begin with.

Spraying the radiator, while good in theory, doesn't work well in practice. Unless they were standing there spraying it with a 2" firehose (thats about 1600gpm) or had a bank of about 4 48" shop fans blowing air over the entire car to simulate highway speed (thats what they do on the dyno), they weren't doing anything more than wasting their time and your money.

'84thunder

Trick Flow Super 23 175cc with 56cc combustion chamber. very good heads
only thing i can think of is that i have my timing set at 14deg and i know that plays a factor in how hot ur engine runs

dimented24x7

iTrader: (2)

I have these heads as well, and the main reason this is an issue is because of what sofa said. Ideally you need to use TTY bolts with alum. due to its porosity, expansion coefficient, and low yeild strength. With the stock head bolts, care is needed when torquing them. Initially they need to be torqued in several stages. Lastly, the aluminum will creep under load (compress down) and unload the bolts. They need to be retorqued after a few heat cycles. My head bolts where down to about 50%-60% of their initial torque after the first run. With a careful retorque, theyre good to go. I have not had any issues with them so far.

Aluminum is nice since it conducts heat much more rapidly than cast iron (no hot spots), and is light, but requires a little more care when installing things like head, accessory, intake, and other bolts. Its another case of automotive justice. If you reach for one thing (light weight performance), you will have to give up another (strength of cast iron).