Inliners International Forums General Discussion Ford Twin turbo 4.9L Ford swap into a '48 Chev.

This is an ongoing project that may be of some interest to someone out there. I chose a 300 six for my car as they can be found very cheap and I'm led to believe that they're quite reliable.

Mocking up the engine fit and dealing with a few issues. The Ford six is about 3" longer than the Chev 216 so at first I thought I would recess the firewall deeper, but after thinking about the loss of interior foot room I decided to move the rad forward instead. To move the rad I just turned the horse collar back to front and mounted the rad to the front instead of inside. Will have to modify the air director panel for clearance to the rad and condenser. Also the width of the accessory drive on the front is too wide for the Chev fenders and hood so I tucked in the steering pump and compressor bracket by milling 1.25" off the mount pads and shifted the motor 1" to the right of center. I noticed that both the Ford pickup and Crown Vic donors had the motors offset to the right, so I figure it must be okay. I also swapped the Ford steering pump which was noisy for a Saginaw pump which even Ford does on their vans as the pump is so close to the driver that the complaints of noise must have been overwhelming. Got the Saginaw pump with mount bracket at Pick-N-Pull. I still have to widen the firewall doghouse to clear the intake, but no deeper.











For motor mounts, I'm using the original ford mount to a perch I fabricated on the right frame rail. But on the left side the Ford mount would interfere with the steering shaft from the R&P, so I kodified an older ford mount by stipping the rubber off and adding a plate to use a common Chev mount.

For turbos I'm using two KKK series K14 units, which are T25 size and mounting them directly to the exhaust manifolds with homemade adapter plates. It's convenient that these engines come with Fenton like manifolds and with the Ford's port layout you can mount a front manifold on the rear 3 cylinders, so both outlets are parallel. A little modification is required to bolt the rear one up.











I drilled and tapped another hole in the head under E4 and used a stud with red high temp locktite as the hole goes into the water jacket.



And here's the turbo adapter plate.

To simplify the intake plumbing a bit, I modified the plenum and adapted a single throat throttle body off a 302 Mustang to replace the two throat T/B. The flow into the plenum is probably compromised a bit, but I figured the boost pressure will make-up for it.

A few little things on the engine mods. First a do-over of the thermactor plugs in the exhaust ports. I had earlier just cut off the AIR nozzle tubes and welded the old fittings shut. But that looked pretty ugly. So I made new plugs that drop into the port followed by threaded plugs to hold them in. The threads in the head are 9/16 – 18 NF so I went looking for that size set screws without any luck at reasonable price, so I wound up using #6 ORB hydraulic port plugs and cutting the heads down in the lathe so they would screw down into the port. A #6 JIC cap was used to hold the plugs in the lathe chuck. Looks much cleaner now.

Saga of a six (sometimes lady luck shines her light on you)

So, I bought a twenty year old $700 donor truck to get an engine for my project. As the truck was a runner, I could test drive and evaluate the engine before buying it. The seller admitted that the rad had a leak that he addressed with Bar's Leaks. Okay, so the test drive around the block went okay, but for the steering pump being so loud that you could hardly hear anything else. The plan was to drive it home 250 miles over the Hope Princeton Hwy. As I got up to Allison mountain pass it boiled over big time. I put more water in it and limped along a few miles, but it kept overheating so I called a tow truck to take it the rest of the way home (125 miles) as I would have had another climb over Sunday Summit. When home, I found that the coolant was not circulating at all. So when dismantling the truck I took the bottom tank off the rad to discover that the core was totally plugged with Bar's Leaks. The engine also was a replacement engine from, I assume, an auto wrecker, so I have no Idea how many miles it had on it.

Fast forward to last week, my engine guru friend, fellow Inliner Dick Knorr 1573, took the engine to go through it to see what it needed in anticipation of turbocharging it. I expect a relatively mild turbo job with a stock spec engine and 8 psi boost, give or take. Although Ford 300 sixes generally have a good reputation for durability, I also read on the internet that they are susceptible to cracks in the combustion chambers and piston skirts. So after the overheating, I'm expecting bad news, maybe a cracked head, needs a rebore and crank grind etc.. Well it turns out all the news is good. It's a standard bore only worn half a thou, the crank is standard and no damage, the cam and lifters good, the head did not show any cracks when checked with dye penetrant and the head has been worked on before as it has the valve guides sleeved. Looks like no machine work required, just a light hone to restore the cross hatch and it should be good. I'm a happy camper!

So to cope with the turbo we're going for new Speed Pro hypereutectic pistons, new timing set with aluminum cam gear, high volume oil pump, ARP rod bolts and head studs and new rod and main bearings. I'll also clean up the ports and combustion chambers to remove potential hot spots, unshroud the valves and lower the CR a bit.

So a change of plan. We were visiting our daughter in Australia and picked up an Aussie Speed intake while there as it would make the engine look more traditional for a hot rod. And I saved the shipping cost by bringing it home in the suitcase. And now that the intake is not covering the valve cover, I thought a GMC valve cover would be a fitting upgrade.







Aussie Speed wouldn't machine the intake for injectors, so I had to do it myself. Had to buy a 7/16 reamer and cut up an old fence post to mount the intake for drilling.

Here's the oil supply fitting for feeding the turbos.

Thanks, looks great.
The Aussie manifold should have much better response time to go on boost than the long runners.
Many decades ago, I described a turbo system for a Corvair 4 carburetor (140 hp) engine to a Corvair LSR owner, who warned me that high plenum and runner volume is just that much longer before pressure reaches the intake valves.

What did you intend to run for ring end gap?

As for ring gap, I'll have to ask Dick as he put it together. Hopefully he remembers or has notes.
For throttle response, I'm expecting the two small turbos to spool up quicker than a single large turbo.

KB says hypereutectic + boost for street use needs as much as .008" per inch or .032" for 4" bore. This is about double the normal gap for NA cast pitons.

I found Dick's assembly notes and the ring gaps are:
Top ring - 0.022 (0.0055/in.)
2nd - 0.020 (0.005/in.)
Oil - 0.028

Weisco says 0.0055/in. for street turbo application, but they want more than the top ring for the second ring. Dick's notes reference 0.0035 for the second ring, so will have to see where he got that. At running temperature I would think that the second ring will be much cooler than the top and thus the gap will be greater than the top ring during operation. Maybe need more study on this.
Another inliner here has an Atlas 4.2L running a turbo for about 4 years now with no issues. His engine was brand new from GM and I don't think it has been opened up at all.

This is really something! You must be a dedicated inliner because this was not the easy swap. Great work. I hope you can post some videos when it is running.

That should be a 17/32 reamer, not 7/16. Will post more as it progresses.