difference between 3B and 7a engine ?

[fluk3]

oki so I became wiser now, thanks.
I think I take a normal 3b engine. and build on is there anyone of you knows how much the original pistons may hold

and if an oil pump from an ABY in better was it a good idea to build it in the 3b block ?

if I can not find ABY engine for my project

or an RS2 engine but then it starts to become expensive. even before I bought tuna parts

[4WheelDrifter]

Original pistons take lots of power. ABY oil pump is no better than a 3B/7A, it is just missing the cambelt roller.
An RS2 engine just costs more, that's the main difference.

[fluk3]

oki thank you so much. but I have one more question.

The top of a 7A and 3B engine what is the difference exactly?

it is because I have a complete ABY top. which is defective it has a small crack to a water line. so I've have a complete exhaust valve set, can be used to 7A top?

There was one who said that the exhaust valves are not the same at the 7A and 3B but is that the material or size?. if it is size then I can not install the valves from my old ABY top

then I have more good reasons to buy the 7A engine. both cams, and I can assemble a top that i can use

[Jamo]

You'd have to drill and tap the block for the ABY cambelt tensioner if your used the ABY oil pump.

there is no need, use the 3B pump and cambelt setup

[Flat on my back]

You'd have to drill and tap the block for the ABY cambelt tensioner if your used the ABY oil pump.

On a 7A block THERE IS NOT ENOUGH METAL to add the ABY tensioner...btdt.

[GazzaG60]

my view is this

other than the extra cooling of the water rail on the long head i can see no reason why 7a cant make power. it is in principle a 16v with another pot and totally standard engine 16v's have done over 400whp. the advantage on the 16v is that you can get a steel gasket from the dealer from an abf.

i know of a guy who made 435whp on a 35r at 35psi on a stock 16v IIRC stacked gaskets.

as its less hp per cylinder i cant see who it wont hold out.

[4WheelDrifter]

oki thank you so much. but I have one more question.

The top of a 7A and 3B engine what is the difference exactly?

it is because I have a complete ABY top. which is defective it has a small crack to a water line. so I've have a complete exhaust valve set, can be used to 7A top?

There was one who said that the exhaust valves are not the same at the 7A and 3B but is that the material or size?. if it is size then I can not install the valves from my old ABY top

then I have more good reasons to buy the 7A engine. both cams, and I can assemble a top that i can use

I modified a 7A head by drilling the 3 extra holes and 3 extra threads for the water manifold. It's been done plenty of times by other forum members too. I then used all the internal parts from my 3B head.

The valves are the same size, but the 3B has sodium filled exhaust valves, the 7A does not in my experience. Although there is a mention of it in the workshop manual, so maybe there are some 7As out there with sodium valves. It's easy to tell if they are or not.

7A heads are generally in better condition than used 3B/ABY/AAN/AAN heads, so if you don't mind a little machine work there are benefits to using one.

[fluk3]

oki I can actually with good reasons, buy the 7A engine and use the old parts from ABY top except the cams and get a god top whit ABY valvs and 7A cams, that fits on a 3B engine

[fluk3]

so I had purchased the 7A engine. I think I was just lucky I got an complete engine which has been running around 170000 km with 01A gear box on. The engine is fitted with Brand new power distribution complete wiring and box. and has brand new oil on it: D and I bought it all for only 2500 Dkr = 330 Euro he he

many thanks for your help everyone.