2.8 TopEnd Swap Clarification Needed?

[blownarrow]

Hello,
I need a little clarification on an top end swap.
I have a 89 RWD 2.8 block with flat top pistons.
I want to drop on a set of Aluminum heads.
I want to run the RWD .040 head gasket and need to know If I will need
to cut valve relief's in the pistons and I also need to know what head
3100 most likely but wondering will the 3400 valves hit the cylinder walls of the 2.8?
I'm going to the yard this weekend and want to know what to grab...
Also what head should I "Not Grab" what head "will not work" with the older RWD block...
Oh and b4 i forget, headers I have custom set of headers on my Iron Heads will they fit the Aluminum heads port spacing? Distance between each other?
Or will I need new headers...ugh?

ummmm looks yummy!

[1988GTU]

The headers will need to be modified a little bit. Oblonging the bolt holes was enough from a previous install (iron head headers on a aluminum head) that I did, but I had to "ping" the headers on the side to clear certain things from the new alignment of the headers (was like 1/4") .

[jdv]

The 3400 heads will fit but you are going to find away to do the ignition because the dissy will not fit with 3400/3100 heads.AFIK the external crank trigger in store will not fit the rwd
pulleys since you don't have a trigger wheel on the rwd crank you will need a custom piece.Forcedfirebird is working on a rwd crank trigger but nothing yet.I am in the same boat so let me know how things work out.

[ForcedFirebird]

Well, I would gather that since the FWD pistons come .020" out of the bore, and the iron heads are about -.010" that you should be fine with the .040' gaskets and not worry about piston to valve clearance. Dave ran a set of .040" gaskets n his 3500 with long duration and made contact, but do the math on that one

You do realize your CR is going to be crazy with flat pistons and 3x00 heads?

[BillS]

The 3400 heads will fit but you are going to find away to do the ignition because the dissy will not fit with 3400/3100 heads.AFIK the external crank trigger in store will not fit the rwd
pulleys since you don't have a trigger wheel on the rwd crank you will need a custom piece.Forcedfirebird is working on a rwd crank trigger but nothing yet.I am in the same boat so let me know how things work out.

The RWD 3.4 used a crank trigger in the pulley AND a cam trigger (the latter to run the SFI), as well as the conventional trigger in the middle of the crank..

If he wants to switch to the OBD1.5, or use a late 80s ECM, he can run the centre crank trigger (the threaded hole exists at least in the later 2.8 blocks) and have DIS, which is a big move ahead from the distributor in terms of maintenance.

One thing no one has mentioned though - will he not end up with very high compression, running pistons from a cast iron head engine with alloy heads? As in way beyond the ability of pump gas?

[blownarrow]

ok so it sounds like the distributor is going to be my biggest obstacle?
now is this due to the heads or the manifold?

[BillS]

On the last cast iron heads, the intake interferes with the distributor, and I believe it is the same thing on the alloy heads (Have to take a look at my other engine). Not easy to solve. Like I said, best way is to convert to DIS.

[blownarrow]

On the last cast iron heads, the intake interferes with the distributor, and I believe it is the same thing on the alloy heads (Have to take a look at my other engine). Not easy to solve. Like I said, best way is to convert to DIS.

umm...
Bills I was meaning to ask a while back, but is that your motor you have for an advitar..

[jdv]

Only the newer 3.4 rwd blocks have the hole for the trigger.

[BillS]

umm...
Bills I was meaning to ask a while back, but is that your motor you have for an advitar..

Yes, one of them - I have a turbo Fiero, a 2004 3400 minivan and that motor, which is installed in an old MG with a body conversion.

See http://www.rhodo.citymax.com/i/non-rhodo/enginebayj.jpg



and

http://www.rhodo.citymax.com/i/non-rhodo/side1resize.jpg

[BillS]

Only the newer 3.4 rwd blocks have the hole for the trigger.

We are talking about the threaded hole on the side of the crankcase. They were on earlier engines as well, they just weren't used for that, and had a plug in them, as I recall.

I use that hole for a knock sensor on my turbo 3.2.

[blownarrow]

I was going to say, I've seen you beautiful car on the V8MG site...
Look like a fun car to drive...

[BillS]

2000 lbs. + 200 BHP = tons of fun!

[ForcedFirebird]

One thing no one has mentioned though - will he not end up with very high compression, running pistons from a cast iron head engine with alloy heads? As in way beyond the ability of pump gas?

I mentioned it in the post directly above yours

We are talking about the threaded hole on the side of the crankcase. They were on earlier engines as well, they just weren't used for that, and had a plug in them, as I recall.

I use that hole for a knock sensor on my turbo 3.2.

No, the ignition pickup uses a totally different boss than the ones found on the 2.8's and 3.1's, trust me

The 3.4 crank sensor looks and mounts very similar to the cam sensors found on later blocks. The mounting boss for it is a smooth drilled hole and the sensor itself has a tab on it to accept a bolt to keep it held in.

[geoffinbc]

Only FWD blocks has the boss cast in the block for a crank trigger. I don't ever recall seeing a RWD block with the boss for the crank trigger, except the 3.4L Camaro

My Isuzu block for instance has the boss without the hole machined into it. However my 2.8L S-10 block did not.

Your distributor problems arise with the use of the 3X00 intake, not the use of the aluminum heads. But unless you make a custom intake I guess your screwed.