[donchicago48]

I did a three-angle valve job on the first cylinder head today. The valve seats cleaned up nicely and do not need replacement.
I heated the head to 190 F in the oven and put the valve guides in the freezer. Previously, I carefully radiused the valve guide port ends so they would not shave metal off the valve guide bores.
The new valve guides drove into the heads easily using the improvised tool above and a Sioux Air Hammer with low air pressure. I used an Aluminum spacer and a washer to limit the travel of the guides into the head and set the valve guide height correctly.

 

[donchicago48]

 

[donchicago48]

I assembled the Cylinder Heads with all-new parts. The valve seats required minimal cleanup and none required replacement. I used a high-quality KwikWay valve seat cutter set to lightly renew the valve seats. The intake valves are back-cut in order to improve air flow.
It appears that later heads have better combustion chamber design with less valve shrouding than these 1991 heads. The 1994 - 1997 heads were the first improvement. Later heads used smaller valve stems and different valve sizes. Intake valves were larger and exhaust valves were smaller. Port shapes changed too.

 

[donchicago48]

I assembled the Cylinder Heads with all-new parts. The valve seats required minimal cleanup and none required replacement. I used a high-quality KwikWay valve seat cutter set to lightly renew the valve seats. The intake valves are back-cut in order to improve air flow.
It appears that later heads have better combustion chamber design with less valve shrouding than these 1991 heads. The 1994 - 1997 heads were the first improvement. Later heads used smaller valve stems and different valve sizes. Intake valves were larger and exhaust valves were smaller. Port shapes changed too.

I visited Victory Auto Wreckers yesterday and bought a pair of 1994 Cylinder Heads from a DGC 3.3 L V6. I also bought an Intake Manifold and Throttle Body from a 1999 Chrysler T & C 3.8 L V6. The heads had about 1/4" of caked on oil deposits from leaking valve covers. The internal oil passages were amazingly clean. It took quite a bit of Simple Green cleaning just to find the casting number that ends in 510. These heads have somewhat less squish area and Intake valves are unshrouded compared to the 015 casting number heads. The Intake ports are a bit larger than the earlier ones. It appears that the 1999 Intake will match these 510 heads with minimal grinding. Photos to follow after a few gallons of Simple Green and a lot of elbow grease.
The 1999 3.8 L throttle Body has a considerably larger Butterfly valve and discharge diameter than the 1991 3.3 L model. The Inlet diameters are the same on both Throttle Bodies.

The 1999 3.8 L Throttle Body (top) is about 5 mm larger than the 1991 TB.

Here is the 1999 3.8 L TB Gasket compared to the 1991 Intake Manifold Inlet.

Here is the same gasket on the 1999 3.8 L Intake Manifold Inlet. Note the black grunge from the EGR on the 1999 engine.

Here is the 1999 TB with the 1991 3.3 L Throttle Position sensor and Idle Air Motor installed.
I will block off the EGR Valve ports on the 1999 3.8 L Manifold and use a 1/4" male IPS to 3/8" Female IPS adapter to install the 1991 3.3 L MAP sensor on the 1991 Manifold.

 

[Mr. Minivan]

Fantastic Thread, following.

 

[donchicago48]

Thank you. My build is a work in progress. Today I disassembled and cleaned the 1994 510 cylinder heads. I will check the combustion chamber volume on both sets of heads. The '94 heads are definitely better designed with better ports, tuliped valves and less shrouding.
I should have the engine back from the machine shop before Christmas.

 

[donchicago48]

Here is the 1994 DGC donor vehicle at Victory Auto Wreckers in Bensenville, IL after I removed the cylinder heads.

 

[donchicago48]

Here are the 1999 3.8 L V6 Lower Intake Manifold casting #4694494AA (TOP) and the 1991 3.3 L V6 Lower Intake Manifold casting #4483602 (BOTTOM). There are not very significant differences between the port sizes or the runner sizes.

Below: There are significant differences in Plenum Size and Runner Length between the 1999 3.8 V6 Upper Intake Plenum casting #4694368C (TOP) and the 1991 3.3 L V6 Upper Intake Plenum casting #4536020 (BOTTOM). The 3.8 L Intake has longer runners and a larger Inlet bore to match its larger Throttle Body.

 

[donchicago48]

A word about Pistons for this build:
I am using flat-top 2007--2011 Chrysler 3.8 L V6 pistons for this build. The pistons are UEM Silvolite 3259HC.STD pistons. They are for a Standard 96.0 mm 3.8 L V6 Bore. That is 3.0 mm larger than the 3.3 L V6 Bore. This model piston is unique in that it has a Compression Height (distance from piston pin center to top of piston) of 1.261", nearly identical to 1.260", the standard Compression Height of Chrysler 3.3 L V6 pistons. Most Chrysler 3.8 L V6 Pistons have a Compression Height of 1.283" or so. They could not be used with a 96 mm Bore 3.3 L V6 that has 6.181" Connecting Rod and 3.189" Stroke Crankshaft. The pistons could protrude from the block too far.
Here is the calculation for determining how far the pistons will protrude from the block:

One-half of 3.3 L V6 Stroke. 1.595"
3.3 L Connecting Rod Length 6.181"
3259HC Piston Comp Height: 1.261"
------------
9.037"
minus Block Deck Height. - 9.016" = +.021" protrusion. Piston to cylinder head squish clearance about 0.049".

Silvolite HyperEutectic Piston w/ Mahle 1.2mm, 1.5mm, 3.0mm Rings. Moly-filled top ring.

 

[donchicago48]

1999 3.8 L V6 Intake Plenum with 1991 Intake Hose and Air Box Cover.

1991 3.3 L V6 Air Filter Box with modified Inlet. Restrictor Orifice removed and air path opened up and smoothed out.

 

[donchicago48]

Below: 1991 Chrysler 3.3 L V6 Air Filter compared to a 260 HP 2002 Acura 3.2 TL Type S Air Filter. I suspect a larger Air Filter would increase air flow and add some additional horsepower.
I will fabricate a cold air Inlet for the SBEC engine controller housing.

 

[donchicago48]

Combustion Chambers of early 1989 - 1993 X015 Cylinder Heads (Top) and later 1994 - 1997 X510 Cylinder Heads (Bottom).
About 1/3 of the Intake Valve is shrouded on the early chamber. The later design has much less Intake Valve shrouding and reduced Exhaust Valve shrouding.

 

[donchicago48]

At 56.2 cc, the Chamber Volume of the early X015 Cylinder Head is slightly larger than the AERA Engine Builders Association value range of 52.2-55.2 cc. This Cylinder Head was resurfaced .010" so it had even larger Chamber Volume from the factory.

 

[Road Ripper]

Just read the whole thread. Enjoy watching a build snowball to bigger/better things (more powar! ).

Should have just used the 4th gen heads, with bigger valves and 7 rocker shaft bosses instead of 4. Better design. Also, 4th gen cam has more lift.

I once fit a 4th gen lower intake manifold into a 3rd gen engine in a junkyard, so I know it will bolt up. When I was driving my 3rd gen, I was wondering if using the 4th gen intake and exhaust manifolds would boost power. The 4th gen exhaust manifolds flow the best. The shorter runner 4th gen intake plenum would have lost some low-end torque though.

The 3rd gen rear axle fit into a 2nd gen body? I kind of did the opposite; put a 2nd gen rear axle under a 4th gen van, and it was narrower by 1 1/2". I had to use ratchet straps to suck the leaf springs together to get the axle bolted to them. I did it so the body could roll onto a trailer and get hauled away, as I was keeping the original rear leaf springs/axle for spare parts for my other van. Since 3rd and 4th gen vans share the same rear axle/suspension parts (well, early 4th gen anyway), wouldn't that make the 3rd gen axle too wide for your van?

Cars are like big puzzles to me. It's amazing what you can take apart and fit together, from totally different vehicles.

 

[donchicago48]

I'm using the 4th Gen Cam with the '99 upper and lower manifold and bigger throttle body. I have 2.5" low restriction exhaust from the manifolds back.
I also am installing three wide band O2 sensors. Later I will install a different ecu. I will probably install a Megasquirt.

 

[donchicago48]

Comparison of 3rd Generation Chamber (Left) with 4th generation chamber (Right)

 

[donchicago48]

The 1994 X510 Cylinder Head Chamber measures about 56.4 Cc, almost identical to the earlier 1991 X015 Cylinder Head Chamber Volume above.

 

[donchicago48]

FedEx delivered a stocking stuffer to me yesterday. These are my new custom-made Stainless Front Brake Hoses from Crown Performance, Inc. of Vista, CA.
I recommend this company highly. They were helpful at every step of the ordering, fabrication, and delivery process. It was truly a pleasure doing business with Crown Performance.

 

[donchicago48]

After endless searching and disappointments I finally located 10 Pioneer CRB-700 Connecting Rod Bolts for my '91 DGC 3.3 L V6 engine

 

[donchicago48]

Just read the whole thread. Enjoy watching a build snowball to bigger/better things (more powar! ).

Should have just used the 4th gen heads, with bigger valves and 7 rocker shaft bosses instead of 4. Better design. Also, 4th gen cam has more lift.

I once fit a 4th gen lower intake manifold into a 3rd gen engine in a junkyard, so I know it will bolt up. When I was driving my 3rd gen, I was wondering if using the 4th gen intake and exhaust manifolds would boost power. The 4th gen exhaust manifolds flow the best. The shorter runner 4th gen intake plenum would have lost some low-end torque though.

The 3rd gen rear axle fit into a 2nd gen body? I kind of did the opposite; put a 2nd gen rear axle under a 4th gen van, and it was narrower by 1 1/2". I had to use ratchet straps to suck the leaf springs together to get the axle bolted to them. I did it so the body could roll onto a trailer and get hauled away, as I was keeping the original rear leaf springs/axle for spare parts for my other van. Since 3rd and 4th gen vans share the same rear axle/suspension parts (well, early 4th gen anyway), wouldn't that make the 3rd gen axle too wide for your van?

Cars are like big puzzles to me. It's amazing what you can take apart and fit together, from totally different vehicles.

I installed the 3rd gen axle so I could put 4th gen hubs, backing plates, Calipers, and rotors on the van. I removed the weight sensitive proportioning valve and installed an adjustable Wilwood proportioning valve.