hybrid 2.8

[dusterbd13]

id like to mess arund and build a hybrid on the cheap for my autocross truck (2.8 s10). to stay classed where i am, i need to retain the 2.8, stock displacement. anything larger will get me ratcheted way too far up.

so, i was thinking hybrid. i know the 3500 setup on the 3.4 is the hot ticket, but what about the 2.8?

3100? 3400?

its gotta be streetable, as its a regualry dreiven truck. not a DD, but 3-4 days a week. that means reasonable compression ratio, etc.

thanks for any help you can throw my way.

Michael

[montess408]

if you want to do it on the cheap you should look at the small port 3100 top end. you can get them dirt cheap and will be a improvement on the 2.8 stuff

[bszopi]

Remember, that if you go with a 3x00 top end, you will have to swap to an EFI and DIS ECM, and all associated wiring.

[carbon]

what would be the benefit of using the small port stuff... would the large port swamp it due to the lower displacement?

Also I believe he is going to need different pistons for that as well unless he wants really low compression, correct?

[Canyonero]

Really high compression actually. The 3x00 uses dished pistons.

[no_doz]

im 99% positive i read somewhere on this site that the 3500 topend wont work because the combustion chambers are too large for the 2.8-can i get a confirmation on this?

[Canyonero]

Yeah, I read that too. 3100 is probably your best bet.

[no_doz]

what compression would the 3400 or 3100 heads give you with a late 80's 2.8 s10?

[dusterbd13]

no doz: exacly what i was just wondering.

also, with the hybrid, i realize that ill need to do a MPFI conversion to rid myself of the TBI.
what source and parts?

also, what is involved in the DIS changeover?

any idea what kind of power im looking at here? if its not a pretty good bump, it wont be worth it. and im open to cam changes to make it work right. also open to porting and polishing the heads, intake, TB, etc.

just tell me what i need to do here.

were working from a 87 s10, 2.8 five speed. mostly stock.

Michael

[bszopi]

Use the CR calc (http://60degreev6.com/content/CR_Calculator) to figure out what your CR will be. You'll probably have to run a stock CR for a couple different engines to get all the numbers you need, but it will allow you to see for yourself.

[lampy]

FWIW camero/firebird 2.8 had a multi port set up for rwd. Got intake, dist., wiring harness and computer cheap at the local pull and save. Just havent had time to bolt it up. I'll probably go with a Mega Squirt computer when I do get around to that project. Dont know what the gain in HP is tho.
checked the family tree TBI 125 HP 150 torque
MPFI 135 hp 160 torque

[2.8/3400 1985 Camaro]

CR is going to be really high, 14.6:1, I have a 2.8 block to 3400 upper in the works myself, I'm still hunting down info on whether or not that is a manageable CR, and how I can mount the crank sensor to convert to DIS, if you get the ignition module and coils off of the same donor engine as your top end, from what I've read your stock 2.8 ECM can run it, because it sends the same signal as it did to the dizzy, the hard part is figuring out how to rig a crank sensor for it, and thats where I'm held up atm(on research, build is still in tear-down phase). As for HP/torque gain, I read 40 hp for a run of the mill hybrid, but thats using your stock 2.8 cam.....I'd expect over 200 hp and torque with a big enough cam(I'm getting a big honking 3400 race cam....) and hope to hit 225 between the cam and hybrid swap, and later, aim to hit 300 hp/torque, with headers/exhaust and ported and polished heads/manifold/plenum and a 65 mm throttle body, these are the targets I hope to hit mind you.....
Btw from what I've read the DIS conversion is necessary....the lower intake manifold covers up the hole for the dizzy.

[85maro]

There's nowhere to mount the sensor, you'd have to drill through the block to use a fwd crank 7X sensor on the 2.8 which is why most people swap to a 3.4 block out of a '93-'95 f-body. You could however try making your own crank signal out of the 24X sensor off a 3.4. You'd need the timing cover (and pan if its a different style), the 24X sensor, the harmonic balancer, a welder and a whole lot of patience to stich weld all the holes you don't need closed. A degree wheel might help too. That's something I was considering experimenting with on my 2.8 before I rip it out. There's a few kits out there as well, just do some research. You can use dished pistons from a gen 2 2.8 for a useable c/r.

[2.8/3400 1985 Camaro]

Hmm, well I already know for a fact that I need the timing cover and power steering pump as my current ones won't fit with that upper, so I'll need a 24x sensor and harmonic balance from a 3400? and what holes need closed off?

As for CR I would actually like to go that high if its doable, do you know how high I can go without encountering detonation? Originally I had planned turbocharging down the road but at this point I think I just want to stay N/A and tune the hell out of it if I can get in the neighborhood of 300 hp I'll be happy. Also if 14.6:1 ratio isn't possible due to detonation/knock what is the highest possible, and or would a higher octane than 87 help allow me to get CR up there? And at very least I need 10.5:1 for the cam...Also the 14.6:1 CR is the calculated CR, I don't know what the dynamic CR is or which one I need to go by for that matter....

[2.8/3400 1985 Camaro]

Also the only sensor I need is crank right? (to setup DIS) meaning since it reads off crank and not cam, the sensor I need won't change with a new cam? also does the hole where the dizzy used to be need sealed off?
I found two crank sensors here:

http://shop.advanceautoparts.com/webapp/wcs/stores/servlet/PartSearchCmd?storeId=10151&catalogId=10051&langId=-1&pageId=partTypeList&searchTerm=crank+sensor

Which one would I want? And other than mounting it I just need to hook it up to the ICM and hook up the ICM with the ECM connectors that went to my dizzy right?