2.8 TopEnd Swap Clarification Needed?

[blownarrow]

So what I'm getting is my
2.8 Rwd with 3100 heads and .040 head gasket I'll be running 12.57:1 C.R.
And If I run the 3400 heads I'll be at 11.97:1 C.R.
But the Gen2 heads will give me the same C.R. but the performance of the head is down?
Compared to the 3x00 heads? right???

[bszopi]

I need to make a user's manual for the calc...

The best way to use it would be to do some "stock" calculations and write down values for heads, pistons, etc. Once you have a list of some of the components you want to use, then go to the "User Entered Values" and plug in different combinations to see what the final CR would be with various stock components mixed and matched.

[ForcedFirebird]

So what I'm seeing is the cc for both the 2.8Alm and 3.1alm and 3100 heads are the same 26.4cc...
Great the calculator works really well... Where's the button that tells me it's flow rate
or explains the difference between the two?
I don't want stock C.R.'s just to know what will work best on my 2.8 bottom end.. :-D
please

"Just remember the 3x00 pistons protrude from the block, the iron headed stuff is below deck. "
so will this lower any C.R. gain I should have got? or are you saying "don't get these"

It doesn't give flow numbers lol.

Did you use the "user entered values"? Just put in whatever pistons you want, or change the head/piston values for your motor to compression.

Late Gen3 pwns Gen2, and 3500 are awesome, but they won't fit the bore of a 2.8 or 3.1 (same size).

[blownarrow]

So what I'm seeing is the cc for both the 2.8Alm and 3.1alm and 3100 heads are the same 26.4cc...
Great the calculator works really well... Where's the button that tells me it's flow rate
or explains the difference between the two?
I don't want stock C.R.'s just to know what will work best on my 2.8 bottom end.. :-D
please

"Just remember the 3x00 pistons protrude from the block, the iron headed stuff is below deck. "
so will this lower any C.R. gain I should have got? or are you saying "don't get these"

[ForcedFirebird]

Looks like there are some inaccuracies - a 3.4 iron head motor is 9:1 but shows as 9.54 in the calculator. Am I missing something?

As far as I know all the dimensions in the calculator were measured by people here on this site.

[BillS]

If you want to play with compression ratios and view stock volumes of the heads/pistons you use, we have the CRcalculator...

http://60degreev6.com/content/CR_Calculator

Looks like there are some inaccuracies - a 3.4 iron head motor is 9:1 but shows as 9.54 in the calculator. Am I missing something?

[ForcedFirebird]

Ok so I want the 3rd gen Alum heads and manifold, not the 2nd gen Aluminum heads
Right?
Will i get the same Comp Ratio with the 2gen heads?
Whats the diff between 2gen vs.3gen sorry More Clarification Needed...

If you want to play with compression ratios and view stock volumes of the heads/pistons you use, we have the CRcalculator...

http://60degreev6.com/content/CR_Calculator

EDIT: Yes, you want late Gen3 '00 up in a cple words.

Just remember the 3x00 pistons protrude from the block, the iron headed stuff is below deck.

[blownarrow]

Ok so I want the 3rd gen Alum heads and manifold, not the 2nd gen Aluminum heads
Right?
Will i get the same Comp Ratio with the 2gen heads?
Whats the diff between 2gen vs.3gen sorry More Clarification Needed...

[blownarrow]

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.

Ah ha... There's what I'm looking for...

[BillS]

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.

Well my original 1988 Fiero block has the boss cast in it - I expect they were using the crank position sensor in some other application by that time?

John, sorry, I missed your reference to compression. As for sensors, the 3.4 Camaro engine has the one in the side of the block as I mentioned above, the special front crank pulley with a sesnor bolted to the fromt timing case, and also a cam position sensor at the top of the block, which we remove and plug if we don't want to bother with SFI.

As for distributor ignition, I like the DIS a heck of a lot better (maybe it is having to rebuild my distributor on the Fiero every few years, probably due to the heat near the turbo). In any case, some upper plenums will allow some modification - cutting in to them to clear the distibutor and welding a patch on them, without unduly interfering with flow. I have no idea if you can do this with alloy heads, but I have heard of people doing it with the Camaro 3.4 top plenum shown in my MG cobversion pics. Maybe such a solution might be possible on a 3400 as well?

[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.

[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.

[BillS]

2000 lbs. + 200 BHP = tons of fun!

[blownarrow]

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

[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.