Impulsive 3.8 swap.

[WarWagon]

I've been after this machine for a while and I finally was able to get it, This is a very old swap that has been done about 20 years ago.
Machine: 1984 Isuzu Impulse
Swap is: '79 turbo 3.8 block that has a lot of Kenne-Bell parts like a 1XB camshaft, valve locks retainers and valve springs even a KB #1 intake manifold with a Holley vac secondary 600cfm carb. Later turbo aluminum valve covers and custom ceramic coated really really long tube headers, 2.5" collectors into an H pipe that has two cat converters and a Ravin muffler with turn down by the rear axle.
Borg-Warner T50 5 speed transmission.
Narrowed 7.5" differential with stock axle tubes welded on, stock 4 lug axles.
Holley FPR and Summit electric fuel pump. Fuel system is a return style with a nice stock EFI baffled fuel tank.
Car has: A/C, power steering, cruise control, all power creature comforts stock.
This machine was in Ohio it's whole life with a quick stint in Indiana and now home in WV.
I'll have owned it for two weeks on July 7th.
This engine runs extremely well and I've had it to 7000 rpm a few times now already and it just rips. Idles like a stock camshaft around 900 rpm and lots of torque everywhere. The engine appears to only have a balancer on the crank not a damper, it's runs great as is and I plan on keeping it NA. I don't know exactly what is done to the engine, I only know what I have paper work for and can visually see and confirm. Some work is done to the heads but who knows to what extent, the block is black the heads are red. I do know this engine turns more rpm and runs better than any of my turbo engines ever did off boost.

 

[WarWagon]

Headers are huge! 30" from bends at the crossmember to the collector.

 

[WarWagon]

Video of me reversing it off the trailer

 

[WarWagon]

One more quick video coming into and up driveway.

 

[WarWagon]

I've loaded and now securing the Isuzu on the trailer for the trip back to WV, I'm under the car in the last pic.

 

[ek02]

Sounds really good. Nicely done swap in a tight engine compartment.

 

[needforspeed150]

I love Larger engine swaps in small body cars

 

[b4black]

Excellent!

 

[mikemcvaney]

Excellent!

Sounds fun

 

[ek02]

I watched the videos again. The 3.8 with a stock rotating assembly and the mods you have make for a fast revving engine when you free rev it. Reminds me of my 3.8. It had a wicked sound when free revved. After I went to the 4.1 with a forged stroker and a BHJ balancer it lost that fast free rev off idle due to the heavier rotating assembly I guess, but pulls way harder than the 3.8 under load. I ran a KB 1XB (great cam), then a KB MK2X, then a KB MK2R. The MK2R had really low vacuum in the 3.8 but is fine in my spare 4.1. I had my roller cam ground to the same specs as the MK2R for the 4.1 with GN1 heads in my truck now. A 100 shot of N2O would be fun in that car. More if you knew what pistons were in it and had a way to pull timing.

 

[WarWagon]

I need to get some more video captured of it soon it's getting better. I've thought about putting some N2o on it, perhaps later. I connected the Vaccum advance back up because it wasn't and I don't hear or notice any difference but I see it working so I'll need to view the timing. I really like that MK2R cam it sounds great and I agree the 1XB sure is good, it's somewhat similar to the Comp 206 roller cam in my turbo v6.
I just replaced the diff pinion seal on the lift and seen how the rear suspension is modified. A narrowed 3rd or 4th gen F body rear axle housing with the torque arm shortened, they have a poly bushing on the front of the torque arm working with a custom crossmember that mounts where the stock rear axle torque tube would have mounted. I'm waiting on an oil pan gasket then I'll put it back on the lift and take pictures while I do the oil pan job which might not be bad.

 

[WarWagon]

I'm doing the oil pan gasket job right now and the stock rotating assembly is modified, guessing it probably 9:1 comp with off the shelf pistons. The rest is all rebalanced turbo parts.
https://photos.app.goo.gl/1cwcSp7jsDeZa1XJ6

 

[WarWagon]

I'm not seeing any identifiers on the bottoms of the pistons and I think they are hyper style because of the slipper skirts. This engine has a double roller timing set, must be from Kenne Bell, it's tight.
I did find a socket stuck on the crankshaft bolt & now I have a spare.

 

[ek02]

Looks like you have a decent engine. Balanced and at least hyper pistons. Old school Kenne-Bell stuff was pretty decent. My first even fire was all Kenne-Bell. The second one was all Poston. Same exact parts. Cam grinder was the same company. I ran the KB double roller with a tensioner and never had a problem. It was pretty smooth. I never knew it was not a good idea. The undersize Rollmaster I am using now is also tight. Maybe too tight but it has many miles on it now with no cam bearing wear.

 

[WarWagon]

In car video of a couple quick revs, the tach is accurate I checked it myself twice.

 

[ek02]

That is a lot of rpm. Kenne Bell advertised their cams and Springs would rev to 7000. I set my rev limiter at 6500 to play it safe.

 

[WarWagon]

I never expected this engine to rpm like it does and I'm still blown away how well it runs. I do the same with rpm limit, I only take it to 5800-6000rpm on the street. This car is so light it can be short shifted no problems with the torque it makes. I have to pull the KB intake manifold pretty soon to re-seal the front and rear block valley that's the last oil leak. I'll be looking over the heads a bunch when I'm in there.

 

[WarWagon]

I've been daily driving my '65 Corvair turbo until last week, The corvair made bad noises and I parked it for now. So I'm bringing this Isuzu back up to daily driver status! I needed to take care of a few minor things so it would be worthy.
An oil leak was the last biggest job left, I learned and found out much more about this engine during this repair:
1= it was fully built
2= it's pretty fresh
3= it has higher compression ratio than I thought.
4= I see area's of improvement
This engine has a steel shim valley pan/intake gasket and no front or rear rubber valley rail gaskets and that was the oil leak cause(intake ports also leaked at the gasket).
I had always noticed the heads were a different color than the block and now I see they were also fully built. I seen aluminum poured in the EGR/heat riser passages and milled, light bowl/valve guide work and stock runners on the intake side, nice looking intake valves. Really nice and thick Kenne-Bell pushrods the lifters/camshaft look brand new.
I seen a stacked deck... two head gaskets per bank, a copper head gasket followed by a composite head gasket on top.
I seen an oil mod to get oil to the drivers side of the engine but it was done in the lifter valley and not in the rear on the block. The Kenne-Bell #1 intake manifold is for low or high port heads, well this particular one was never matched to the high port gasket/heads so the intake ports are smaller than the intake ports. Another thing I noticed on this intake: someone welded the EGR passages shut on the flange side then milled them flat, they added coolant ports to the EGR runners on the top side and plumbed it into the cooling system. So now it has a coolant fed intake warmer.

 

[ek02]

I ported two sets of iron heads and put bigger intake valves and filled the crossover and EGR passages with aluminum like Champion does. I sold one set and have the other set on my spare engine. The KB intakes came with smaller ports to fit early and late heads, and also to stop reversion in the intake tract according to the instructions I got when I bought a new one years ago. I ported my intakes to match the heads, so I have no idea if they help reversion. It still has plenty of low and mid range power. I ported the Weiand air gap the same way. It had ports just like the KB. That is an unusual way to get the oil to the drivers side. First time I ever saw that trick. If the compression is really high you should have cranking compression over 200 PSI, depending on the cam timing. My 4.1 is 10.5 and it cranks at 225 PSI. Glad to see another NA running.

 

[WarWagon]

I'll run a compression test on this at some point, what I seen has me curious. I'm guessing here but with the hyper pistons I see in this engine and the stacked deck of gaskets. This must be at or near 10.0:1 compression and the gaskets were stacked to help bring the static compression down to 9.5-9.0:1
I know it runs fine on 87 octane fuel.
I really enjoy this engine in its NA form, it's fun and has a sound like nothing else I have.