320 Horse 304

[82wagonlimtd]

There is a guy here in town that has a CJ-7 with a 320 horse 304...at the wheels...he is a friend of a guy who works for me, who is a car guy.....so he kinda knows what he talks about, on the dyno he has 320 at the wheels!! He did alot of head work...I wonder how much can be attained out of a 360?

[Midnightwagon]

dayamm!! thats a gutsy 304 he's got. but question one why a 304? but anyways thats still cool enough.

[porchpiggy]

That is impressive, but I wonder what RPM it's turning to get that number, and what is the low end tourque like.

[82wagonlimtd]

I will try to get the dyno sheets, it is the original 304 that came with it.

[AMX factor]

exactly 304 is kind of a waste. I would have done at least a 360. My lil bro's Jav is hitting 300 hp's with a .030 over 401. Hitting 1/4 mile in mid 12's. He shifts at about 6300 rpm.

[Cliff]

Hey Factor - a 6300 RPM shift point sounds pretty high for a 300 horse motor. And pushing the bottom end too. What is the cam profile? I shift mine below 5500, and I have a RADICAL cam (563" lift 312 duration).

I wouldn't say a 304 is a waste. Remember what Mark Donohue did on the race tracks in the early 1970's with a 304. And look at the Boss 302!

[Wesdog]

I just posted this in another thread but you guys might be interested:

Just to stir the pot a little here's an email I got a couple years ago from Dick Dotson after buying his AMC books and asking him some questions:

************************************
Wes,

Thanks for the positive comments on ebay. I can appreciate your surprise at
seeing the material. It is different in more ways than is immediately
apparent. I should point out that I edited AMC and Jeep newsletters for
nearly 2 decades though I am originally a Studebaker racer/mechanic and
editor. I'm also a long time outdoor/Jeep man and subscribe to several Jeep
groups though I don't follow them very close for obvious reasons. After
watching my own AMC/Jeep letters section and various articles for this long
with my peculiar background, I would never use an AMC 390/401 in any extreme
duty circumstances.

The problems lie in the extremely thin 390/401 cylinder walls with a standard
bore. The situation gets worse as the bore size increases--which is
unavoidable due to ever higher miles and wear. This in turn produces a lot of
wall flexing if higher compressions or super/turbocharger boosts are used,
and of course gasket blowing (note the article on adding head bolts to AMC
V-8s) and cylinder cracking that goes with these conditions. The next time
you build a motor I would suggest that you find a 360 AMC block and install
your 401 crank in it. That's an unusually good motor for its size. (About 385
cid). My favorite among the AMCs is using the 401 crank in the 304 block
(about 325 cid) which gives bearing areas and wall thickness specs few motors
have ever had. We Studebaker people have always been extremely reliability
conscience, which is why we do so well in record breaking at Bonneville and
are able to run such high boosts. Few outside our circle are as keen on the
subject or reliability (no complaint from us).

Low boost supercharging will produce more horsepower from a 360/385 AMC than
anyone could hope for in the most expensive built 401s -- and live to a ripe
old age even in the harshest of circumstances. Unfortunately no such
supercharger is currently available from the industry (less desirable for
off-road turbos do our testing of course). That is what you see us developing
and is the reason you are receiving our technical newsletter. By the end of
this year we'll have at least several larger superchargers in operation to
demonstrate. This is about increasing low rpm torque rather than high rpm
horsepower. 830 lb.ft of torque from a record setting 300 cid Bonneville
Studebaker proves that reliability and low rpm performance can go together.
No current Studebaker drag or top speed car operates over 6000 rpm. That
would get us laughed off most newsgroups now wouldn't it? A very old rule in
racing I learned the hard way in my first serious motorcycle race 50 years
ago -- "you have to finish to win". The same goes for any serious outback
venture. Dick
**************************************

Wesdog

http://www.fullsizejeeps.com/jeeps/files/Misc-Pictures/wesdog_avitar1.jpg

[Stuka]

A short stroke engine is far better for creating hp then a big stroke engine. Large stroke is great for low end, but wont rev as well.

If you look at race prep ford 289's used in the cobra, cobra coupe, GT40, GT350R, they made 392hp at would run at 7500-8000rpm all day long. The 289 can now make around 430hp NA with some new advancments.

Yes the 427SO made more total power, but it was at a much lower rpm.

For a light car (like a Mk1 mustang) the 289 is a sweet engine, because it revs high and fast.

Same goes for the 304, the 304 has a larger stroke, but still is considered a smaller stroke. So in a light car its a great engine.