run 2.9 heads on a 2.8

[kshen66]

I am trying to dig up the past. I know a long time back (probably 2 years ago I read a article about using 2.9 heads on a 2.8. I know the valve arrangement is different and the cam will spin the same direction as the crank unlike the 2.8. I know I will need to have a cam made, and I have somebody that can make me a adapter to run my 604cfm holley 2bbl on the 2.9 lower intake. I already am running the duraspark dist and MSD coil and ignition box. So my question is did anybody out there do this swap or was it just theory. My questions I am wondering are since I am already running a 2.9 crank in my 2.8. I know I had to have the snout of the crank machined down. I cant remember if that was so the 2.8 gear would work on the 2.9 crank or just so the crank would fit the seal in the front cover. I am thinking I can use the 2.9 timing gears and chain, put would prefer to keep it gear to gear like the 2.8. I am thinking if I tell comp cams what i am planning on doing the can gring the cam so if it is spinning the opposite direction than normal it will have the duration I want. I guess my question is does anybody know if there is any work that needs done as far as water passages are concerned. I seem to rember something about needing to drill the heads for water flow? Please dont reply back if you are just going to suggest running a 4.0 or small block. I have been down that road before. I am running the 2.8 so I can stay in the class I am in. Swapping to a bigger engine is not a option for me. This motor is balanced and stroked I just need to get better air flow thru it and the 2.8 heads dont have it.

 

[dangerranger83]

That is one modifiied 2.8 liter you have. Whats the h.p. and torque on it? Never heard of a 2.9 crank in a 2.8. thats something that should be put in the tech library so that others can do.

As for keeping the gears, that is something I agree on. Glad to see that you are keeping the 2.8 and not going to a bigger engine, nomatter what your doing with it.

 

[kshen66]

thanks dangeranger83, I really dont know the numbers it is putting out. I never ran it on a dyno. The machine shop that did the work is estimating 175HP. We are thinking we can get at least another 20 hp out of it with better heads. I talked to one guy that got 15 hp just porting and putting bigger valves in his 2.8 heads. Put everyone I talked to thinks the stock 2.9 heads would flow better than worked 2.8 heads. I got the article for the 2.9 crank deal from this site a couple years ago. there was a guy doing one and there was a link for a web site with all the details on it. It is a fairly simple swap but it is not real practical for street use, unless you want to run 100 octane fuel all the time and dont care about mileage.

 

[dangerranger83]

Never mind on that then!!!!!!!! I think I'll stick with my "stock" 2.8.