6.5 diesel lowering compression ratio

[DIESELDAVE]

It would be cool for somebody to do for sure, but my guess is, that they would spool really slowly / laggy.

ive seen several 6.5s with hx35ws's on them they sounded really good and wasnt slow to spool but that was only on turbo on one 6.5 wonder what 2 will do

 

[turbonator]

might want to check out NMB2s build over on PSN he's got a db2/db4 hybrid pump supposed to be putting out 300+cc

that is just hearsay about 300cc of fuel per stroke... it is out of the specs of these pumps... if he is using a "moose", pump, they max out at 90cc of fuel, or "super-moose pump" which gives 120cc maxed, to get 300cc he would have to have something like .450" plungers, and there is just barely enough meat there for that, let alone 4 of them, the .450" plungers were used in some old ford db pumps... the pump they are using is built by DPS, 4 plunger, but the life span on them can be measured in weeks....

 

[turbonator]

x2, you need to do some turbo map reading to understand a little about turbos, the 6.5l could not spool 2 hx-35, if you are thinking twins, go with 2 gm-4, running off of one bank will change everything with them.... and you will not have enough fuel with a db-2 to break the 210 rwhp mark, when most 6.5l including the optimizers, p-400 are barely doing it... maybe you will be better to build your first motor to just be reliable, and think about breaking 300rwhp when you have a better understanding of it...

 

[DIESELDAVE]

x2, you need to do some turbo map reading to understand a little about turbos, the 6.5l could not spool 2 hx-35, if you are thinking twins, go with 2 gm-4, running off of one bank will change everything with them.... and you will not have enough fuel with a db-2 to break the 210 rwhp mark, when most 6.5l including the optimizers, p-400 are barely doing it... maybe you will be better to build your first motor to just be reliable, and think about breaking 300rwhp when you have a better understanding of it...[/QUOT

its not my understanding sir,,i want to get away from uneven back pressure from only using one bank i want to run both banks ,,its either two turbos or a whipple super chrager which equals no back pressure.i do not know what stanndyne pump i have i know its is upgraded i dont know the model number if i have to i will use 2 injection pumps to fix fuel issues,,in ur statement above u make it look like i know nothing ,,i do not appreciate it sir.

 

[great white]

x2, you need to do some turbo map reading to understand a little about turbos, the 6.5l could not spool 2 hx-35, if you are thinking twins, go with 2 gm-4, running off of one bank will change everything with them.... and you will not have enough fuel with a db-2 to break the 210 rwhp mark, when most 6.5l including the optimizers, p-400 are barely doing it... maybe you will be better to build your first motor to just be reliable, and think about breaking 300rwhp when you have a better understanding of it...[/QUOT

its not my understanding sir,,i want to get away from uneven back pressure from only using one bank i want to run both banks ,,its either two turbos or a whipple super chrager which equals no back pressure.i do not know what stanndyne pump i have i know its is upgraded i dont know the model number if i have to i will use 2 injection pumps to fix fuel issues,,in ur statement above u make it look like i know nothing ,,i do not appreciate it sir.

If its a mechanical pump, it's a db2.

Running two db2's is not exactly an easy feat.

Been done before, but only once and on a tractor.

Db2 are good for about 30-ish hp per cylinder.

Just a question: if you don't know what pump you have, how do you know it's "upgraded"?

 

[DIESELDAVE]

If its a mechanical pump, it's a db2.

Running two db2's is not exactly an easy feat.

Been done before, but only once and on a tractor.

Db2 are good for about 30-ish hp per cylinder.

Just a question: if you don't know what pump you have, how do you know it's "upgraded"?

cause when dad had the truck it needed a injection pump ,it had a older version of the pump on it ,when we took it to the pump rebuilder (moutainneer diesel) he got us to read the model numbers of the pump and he give us a rebuilt upgraded pump i dont rember the numbers but i do know it was upgraded ,next time im home ill get the numbers off from it ,oh and the pump builder turned the pump up all the way with in gm limits the truck did run a lot stronger and had a slight trail of black smoke when going down the road

 

[turbonator]

A guy named Nicklas, from Norway (IIRC), was trying to do a supercharger build, using a 6-71 and 2 - DB2's. Have not had any news from him in more than a year now......

We been doing alot of measuring, calculating and reading recently, to the end of getting the most possible fuel out of a DB2 pump.....6.2turbo, (member here) has probably gotten the most fuel delivery out of one of these pumps. He used .500" plungers. The shoe width on a DB2 is under .470". That means that the shoe does not have a full surface to run on. IIRC, this pump seized and broke cam rings.

My calculations may be way off the mark, but I figure the absolute max that a DB2 pump with the largest plunger of .450" and a modified cam ring with the lobes increased from .073" to .125" (that is cutting it damn close), will still only give 190cc (190ml/1000 strokes). We have not been able to locate these plungers yet, but have a line on .330" and .350". Not sure which other mods John made to his .330" plunger pump, but he did 304hp at the wheels (no drugs).

As many here know, we are building to go over 300 rwhp this time out. Will be our 4th build now, increasing and strengthening each time. We will have a very modified DB2 pump this time, but we feel that to have better reliability and drivability (absolutes), if trying to further the search for hp/torque a change-over in pumps will be necessary.

 

[turbonator]

for starters dave, fill out your signature with the year and the things done to the truck, that way we have a better understanding what you have to work with... since i do not know what motor, year your truck is, i would have to guess that your motor was a pre 1985, and that the cam-ring went to coffee grinds, and that is what was upgraded in it... as for the unbalanced flow, that calls for a center mount or twin-turbo set-up... we have experience with center mount already, and can say it is a night and day difference.... but was purpose built for medium duty platform and would take MAJOR fire-wall mods to fit in a gmt-400.... your intentions seem good, so all i can say(again...LOL) is read,read,read... and just build yourself a good running, reliable motor your first time out, get experience and then build another.....

 

[DIESELDAVE]

for starters dave, fill out your signature with the year and the things done to the truck, that way we have a better understanding what you have to work with... since i do not know what motor, year your truck is, i would have to guess that your motor was a pre 1985, and that the cam-ring went to coffee grinds, and that is what was upgraded in it... as for the unbalanced flow, that calls for a center mount or twin-turbo set-up... we have experience with center mount already, and can say it is a night and day difference.... but was purpose built for medium duty platform and would take MAJOR fire-wall mods to fit in a gmt-400.... your intentions seem good, so all i can say(again...LOL) is read,read,read... and just build yourself a good running, reliable motor your first time out, get experience and then build another.....

well for starters its a 1991 j code 6.2 with a complete mechaical 6.5 top end on it.
its in a 1991 p;30 box van but my goal is to get rid of that ugly ass box and use the p30 frame because it is a 1 ton frame and set a extended cab 3500 down on it ,thats why i want to build a complete 6.5 because i already have the whole top half brand new