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2.8 heads
- Thread starter lillypad
- Start date
Mike Armstrong
Bronze Level Sponsor
Hi John, bummer. How did you find out?
I haven't seen my 85' 2.8 run yet. I bought it off the back of a flatbed truck. It looks ok but it very well could be a compression less, cracked, piece of junk. I'll be nervous during that first start attempt.
I'll keep an eye out for heads.
Regarding which pistons to use with a 2.9 crank; seems like the original 75 2.8 pistons are the ones to use. As I recall, the original engine had steel shim head gaskets, so the compression height of the pistons left the piston crown .050 down the hole. If you're stroking the engine with a 2.9 crankshaft and using composition head gaskets, use the 75 pistons.
MikeH
Diamond Level Sponsor
That's what I had read somewhere. And I plan to use the '74/'75 pistons with the higer pin placement.
socorob
Donation Time
It's a shame there's not much in terms of performance parts for these engines. Reading through old Capri forums these guys dropped a few grand stroking these engines with good high comp pistons and their dyno sheets would barely show 200 hp, if that. The ones that went all out with the 4.0 crank would get around 225 or so after spending about 5k.
Bigger isn´t always better.
One thing you need to remember, is that if they are using the 2.6 V6, it is very hard to get 200 h.p. from them. Almost all Capri guys tend to use the same cam specs for the 2.8 V6 as for the 2.6 V6, which is a very different animal. The 2.6 V6 has good breathing on the intake side and poor breathing on the exhaust side, because of the siamesed exhaust port. The 2.8 V6´s are totally the opposite, with better breathing on the exhaust side and not so good on the intake side. To get the most from a 2.8 V6, you need to tilt the duration timing toward the intake side. The 2.6 V6 needs the exact opposite.
I don´t know what a 2.9 stroker V6 will make, as far as power is concerned, but it will not run as well as unless it hads the specs for the 2.8 V6, with the cam timing tilted toward the intake.
Jose
One thing you need to remember, is that if they are using the 2.6 V6, it is very hard to get 200 h.p. from them. Almost all Capri guys tend to use the same cam specs for the 2.8 V6 as for the 2.6 V6, which is a very different animal. The 2.6 V6 has good breathing on the intake side and poor breathing on the exhaust side, because of the siamesed exhaust port. The 2.8 V6´s are totally the opposite, with better breathing on the exhaust side and not so good on the intake side. To get the most from a 2.8 V6, you need to tilt the duration timing toward the intake side. The 2.6 V6 needs the exact opposite.
I don´t know what a 2.9 stroker V6 will make, as far as power is concerned, but it will not run as well as unless it hads the specs for the 2.8 V6, with the cam timing tilted toward the intake.
Jose
I don't know if Jim Ellis ever had his 2.8 dyno'd, but it was scary fast. And, he never even got around to installing the NO system he had planned for it.
Hi Jim,
Jim Ellis´ Alpine is running the cam designed expressly for the 2.8 V6. I have had even the cam grinder at Delta tell me that those specs won´t work, but I have been using those specs for over thirty years and it works. Since you´ve ridden it it, you can testify to it´s effectiveness.
Jose
Jim Ellis´ Alpine is running the cam designed expressly for the 2.8 V6. I have had even the cam grinder at Delta tell me that those specs won´t work, but I have been using those specs for over thirty years and it works. Since you´ve ridden it it, you can testify to it´s effectiveness.
Jose
The underwear I had on at the time is probably the best testament!
Hi Nick,
The cam comes on about 3K and will pull to about 6.7K, but will safely go to 7K. It will putt putt around town like grannies grocery getter with no drivability problems, but when you mash the gas and it hits 3K, it will come alive like you can´t believe.
Any aftermarket high performance cam will give better performance than a stock cam will, but this cam will out perform any of those cams. Period. They may have a good lope to them when they idle, but this cam does that plus performs.
Jose
p.s. I didn´t come up with these cam specs, my head porter did because of the way the heads flow, so I can´t take any credit for it.
The cam comes on about 3K and will pull to about 6.7K, but will safely go to 7K. It will putt putt around town like grannies grocery getter with no drivability problems, but when you mash the gas and it hits 3K, it will come alive like you can´t believe.
Any aftermarket high performance cam will give better performance than a stock cam will, but this cam will out perform any of those cams. Period. They may have a good lope to them when they idle, but this cam does that plus performs.
Jose
p.s. I didn´t come up with these cam specs, my head porter did because of the way the heads flow, so I can´t take any credit for it.
RootesRich
Donation Time
Agreed. I had the pleasure of "driving" it at an Invasion years ago. Up until a few weeks ago, Jim's Alpine was the fastest Sunbeam I'd ever been in. Even faster than George Fallehy's 302 Tiger I rode in when I was a kid.
Hi Mike,
Jim used an after market cam billet, just to have enough meat to be able to get .518" of lift. A stock cam will only go to about .496-.498" of lift. The rest of the specs are exactly the same. He wanted as much as he could get, so went with a cam core that had enough material to get it. I don´t recommend going over .500" of lift, so you don´t run the risk of valve to piston interference.
Jose
Jim used an after market cam billet, just to have enough meat to be able to get .518" of lift. A stock cam will only go to about .496-.498" of lift. The rest of the specs are exactly the same. He wanted as much as he could get, so went with a cam core that had enough material to get it. I don´t recommend going over .500" of lift, so you don´t run the risk of valve to piston interference.
Jose
alsalp
Donation Time
Did Jim have to use a truck block for the bigger cam journals?
What exactly is the atvantage to the 2.9 crank? If I understand right it about increasing compression ratio with 2.9 rods and 2.8 pistons?
What does the cam card say on the delta cam?
Al