- Location
- Southern Maryland
My other car is an 85 FWD Cadillac DeVille. I'm swapping the stock 4.1L for a 4.9L engine from a later production
These are sideways pushrod V8 engines, with aluminum block and intake and cast heads. They are the engines that were used prior to the Northstar DOHC sideways V8 engines. The 4.1 TBI was the first in the series, then they had a 4.5 TBI that was bored out a little, then a 4.5 PFI, then finally a 4.9 PFI that was bored and stroked. They all use pretty much the same block and heads and intake (some of the gasket kits are the same), modulo the differences you'd expect (TBI vs PFI). There are also internal differences, not just for the larger bore and stroke, but also for fundamental improvements such as changing from flat tappet lifters to roller lifters, and that kind of thing. Most of the user-serviceable parts are the same (rockers, distributor, accessories, etc). The engine bay was also simplified in the later years, with the smog pump and vacuum pump deleted, which frees up a few more ponies. All told the 4.9 produces almost 50% more torque than the 4.1 with just 20% more displacement.
Since my starting platform is TBI, I can't use the PFI manifold easily, so I am swapping in the 4.9 long block and putting a 4.5 TBI intake and throttle body on top for better air flow. In order to get the air-fuel ratio right, I'm using TBI injectors from a 305 TBI setup (common in stuff like Camaros and trucks from the era). I'm not doing anything in terms of hot-rod parts, other than better ignition components. The 4.9 is a really reliable long-lasting engine so I'm hoping that this will get me another 20 years of use.
Here are some pics of the junkyard 4.9 as it is being stripped
In a few days I should have the last parts needed to begin reassembly
These are sideways pushrod V8 engines, with aluminum block and intake and cast heads. They are the engines that were used prior to the Northstar DOHC sideways V8 engines. The 4.1 TBI was the first in the series, then they had a 4.5 TBI that was bored out a little, then a 4.5 PFI, then finally a 4.9 PFI that was bored and stroked. They all use pretty much the same block and heads and intake (some of the gasket kits are the same), modulo the differences you'd expect (TBI vs PFI). There are also internal differences, not just for the larger bore and stroke, but also for fundamental improvements such as changing from flat tappet lifters to roller lifters, and that kind of thing. Most of the user-serviceable parts are the same (rockers, distributor, accessories, etc). The engine bay was also simplified in the later years, with the smog pump and vacuum pump deleted, which frees up a few more ponies. All told the 4.9 produces almost 50% more torque than the 4.1 with just 20% more displacement.
Since my starting platform is TBI, I can't use the PFI manifold easily, so I am swapping in the 4.9 long block and putting a 4.5 TBI intake and throttle body on top for better air flow. In order to get the air-fuel ratio right, I'm using TBI injectors from a 305 TBI setup (common in stuff like Camaros and trucks from the era). I'm not doing anything in terms of hot-rod parts, other than better ignition components. The 4.9 is a really reliable long-lasting engine so I'm hoping that this will get me another 20 years of use.
Here are some pics of the junkyard 4.9 as it is being stripped
In a few days I should have the last parts needed to begin reassembly
