53 series Detroit

[VicS]

Have any of you guys changed from your high lift cam to the newer low lift cam. And if you did, does it make more power?. Has anybody changed to a 4 valve head and kept the old high lift cam? If you don't want to post on here, call me 618 838 2225. Thanks Vic
 

[4010 puller]

Isnt there one style cam they offered that was used when the 53 series engines were turning higher rpm"s(like 3800rpm, Naturally aspirated)?
 

[buickanddeere]

Only a high lift/high velocity cam on the 2-53 and two valve heads.
Now I just may know of a 2-53 with a four valve head crafted on and the high lift/high velocity cam. Equipped with the updated cam follower and valve springs. The springs don't bind but there is no flow advantage and over 2600rpm may float the valves. A waste of time and money vs the two valve head as is. If the cam had been reground then a different issue.
If in a rpm limited class use the two valve heads and high lift/high velocity cam with the last spring update.
Four valve engines first used a low lift/high velocity cam. Then the factory revised to a low lift/low velocity cam.
If no rpm limit then regrind the 2-53 cam to low lift/low velocity and use either two or four valve heads. With lots of spring pressure above factory pressure.
Try as one may, it's tough to beat a bored and stroked H.
 

[ChadS]

he did that all ready! now hes chasing Ms! lol. chads
 

[4010 puller]

Vic:

Earlier (awhile back) you were asking about having blower work done. I think you were installing the new seal kit and teflon coating the rotor tips? Did you find anyone else that does this work other than Team Diesel?
 

[bob7337]

How can a Detroit be a naturaly spreated motor? I thought all 53 71 and 92 series Detroits had a blower on them.
 

[bob7337]

If you want more power,check into gearing up the blower and going to bigger injectors. I know for a fact it can be done with factory parts
 

[PopinJohn]

Naturally aspirated refers to the action of atmospheric pressure filling the cylinder of a four cycle engine when the piston moves to the bottom of the cylinder on the intake stroke causing a low pressure situation in the cylinder. People refer to this as vacuum, but it really isn't, it's simply pressure lower than atmospheric, 14.7 psi.
This doesn't happen on a Detroit two-cycle because when the piston reaches the bottom both the ports in the bottom of the cylinder and the exhaust valves are open at the same time.
A blower is required, not to pressurize the cylinder like a turbo charger does, but is required to scavenge the spent exhaust gases from the cylinder and introduce fresh air for the next combustion event. Without a blower, atmospheric pressure in the air box and the exhaust manifold remain the same at 14.7, so no cylinder filling can occur. In other words, a Detroit won't run without a blower supplying pressure to the air box.
For lack of better wording, Detroit simply designates the two-cycle engines as NA (naturally aspirated).
 

[buickanddeere]

It's written in black and white inside the DD service manuals. A non turbo two stroke is natural aspirated and a turbo'd two stroke is forced induction.
 

[VicS]

No I never found anyone else that does it. But I think he farms out part of the work. I have a blower there right now getting ready for Princeton and Tunica.
 

[VicS]

Thanks for the information. I have a 4 valve head I would really like to try, but thought I should get the cam ground to the newest specs. My diesel guy says there is free horsepower there. I don't know. He admits no big difference in the flow on a bench. Just says they scavage better. I don't want to go over 2600. I have a boat motor dyno now. I am going to know what makes a difference, when I get it figured out.
 

[VicS]

My detroit guy, says the standard cam that came in my 2-53 is good for 2800 rated speed and will turn 3500 with no trouble.
 

[VicS]

Chad bring that H to Tunica along about the end of November. It-ill be a hoot. Vic
 

[ChadS]

vic, you got any use for a 420? freind of mine has one. block looks like it been worked on yrs ago, belive its stuck from sitting. i belive he wants around 1000 for it. i got a green tractor in here now. : )
 

[buickanddeere]

Your DD guy has mixed up four valve 3,4,6,8 and 12 cylinder engines with the 2-53. Four valve engines were rated for 2800 but no two valve head engine was ever rated past 2400rpm. Have that in black and white in the DD manuals too.
Have to go with the low lift, low velocity cam and heavy springs to reliably keep the valves from hitting the piston. And to keep the valve train from floating.
Some guys over rev them for a while but but expect a wham, bang and , silence and smoke/ steam.