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Discussion Starter #1
I just picked up 130hp, intercooled 4bt with a ppump and 180k original miles. It came out a wrecked fedex truck and sat for at least 5 years.

It’s going into a 76 F150, 4x4, short bed. Long story but I won’t have the truck until March, I’m not sure which transfer case is in it, but planning on NV4500 or ZF 5 speed.

For now I’m focused on building the motor, and started tearing it down today. I plan on stage 3 colt cam, new turbo, 4K gov springs, 60lb valve springs, 16* timing, and custom fuel plate. My goal is 250-300hp and 600ish ft/lbs , along with reliability and fuel efficiency

Now what I’m unsure about since this is my first 4bt build and I haven’t found everything thru google.

1. Should I replace head gasket? No obvious signs it is compromised but not sure how much boost the factory head can handle? Plus if I could benefit from larger valves I could take care of it at the same time. But guessing factory valves would allow 300hp

2. Would I benefit from new injectors? If so which ones?

3. Best turbo for my set up? HX30 or HX35. I know it’s discussed a lot but with the colt cam would the hx35 spool faster and reach the power I’m after with little lag?

Thanks for any help or suggestions. If I have missed this information posted somewhere else I apologize and please provide the sticky :)
 

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Welcome to the forum. On question #1, I'd probably say replace the head gasket. Gives you the opportunity to inspect the cylinders and head. I'd recommend you do head studs based on you power plans. Do new gaskets, bearings, and seals on the entire engine. New rod bolts also. No need for larger valves. You can do a 4K governor spring but 3K is normally high enough for gear changes. Question #2. Stock injectors are 5x.010 and can get near 250 HP. I'd probably change to a 5x.012 which would be plenty big. That's the injector size that came on the 250 HP 4bt marine engine. Just be sure the new injectors have the 145 deg spray angle for your P pump pistons. Marine pistons used 155 deg angle. Question #3. If you intend to stay with a single turbo, then the Super HX30W would be the best choice. An HX35W is too big. A better option might be twins. A regular HX30W being fed by an HX35W would be a better choice. Less stress on the turbos than trying to do it with a single. In combination with your power plan, might want to have the head O ring'd. Your boost level is going to be in the 40 PSI range and stock head gaskets get a bit iffy there. On your transmission choice, if you go with the ZF, use the one from the diesel. You will need the larger clutch and flywheel due to the high torque. Member Eggman can vouch for that. Adapting that transmission will take a special adapter, flywheel, and clutch. Also requires some slight mods to the block skirt for starter clearance. That transmission also has better gear ratios for the 4bt than the NV4500. The NV4500 will be cheaper to fit. Which fuel plate are you planning? A #10 would be highly recommended. Might also want to replace the P7100 overflow valve. If this thing has been sitting for 5 years there could be some fuel gum build up inside the injection pump.
 

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Discussion Starter #3
Char, thanks for your response and helpful information. Now I have a good idea of which direction to go. I will most likely use the hx30 super and recommended injectors.

If the #10 fuel plate is recommended, it’s what I will go with. Wasn’t sure which would work best for my application. Also, the 4K was just to have it if I ever needed it. Truck would rarely see over 3k I’m sure. Are 60lb springs still recommended with 40psi boost and 3k spring?

I am also going to pull the head (hopefully this weekend). I have researched the O-rings and ARP head studs. According ARP representative, they have 2 kits: 2000 set which is designed for mostly stock power output, and 625+ custom service for high hp applications. I’m wondering if O-rings are still recommended for the latter?

Thanks again for the help!
 

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HD valve springs are not very expensive and good insurance against floating a valve. The super HD head studs aren't needed unless you're planning a racing engine. Also, those things are quite expensive and require the holes in the block to be enlarged. Even with the better torque clamping of the studs, a stock gasket can only hold so much boost. 40 PSI is sort of the borderline. Member Eggman has his boost limit set there and so far the stock gasket with studs is holding. The O rings provide a better clamping force and provide cylinder sealing should your boost start to wander much higher. Don't confuse those with fire rings which you don't want to use on a street engine. Those are for those no holds barred racing applications. The #10 fuel plate has a good reputation for decent street manners and higher performance. Very popular with the Dodge P pump guys. If this were a no hold barred budget, you could install an adjustable pump gear so you could tinker with the timing. Kind of an expensive item. Requires a billet front cover as well. Another potential mod would be a HD harmonic balancer like Fluidampr. Cummins had one on the 250 HP marine engine and you could use that one as well but it ain't cheap. If you had decided on twin turbos you'd probably need to change to a higher volume oil pump and a 6bt oil cooler. Probably don't need that with a single but not sure a single can do 300 HP. We generally think of a single turbo boost going into the mid 30 PSI range. Also, make plans for a very good intercooler. Higher boost levels create a lot of heat which you want to get rid of. Air coming off the turbo can exceed 300 deg F. That's why those connecting hoses and boots are silicone rubber.
 

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In combination with your power plan, might want to have the head O ring'd. Your boost level is going to be in the 40 PSI range and stock head gaskets get a bit iffy there. On your transmission choice, if you go with the ZF, use the one from the diesel. You will need the larger clutch and flywheel due to the high torque. Member Eggman can vouch for that. 192.168.100.1 192.168.1.1 jpg to pdf
 

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In combination with your power plan, might want to have the head O ring'd. Your boost level is going to be in the 40 PSI range and stock head gaskets get a bit iffy there. On your transmission choice, if you go with the ZF, use the one from the diesel. You will need the larger clutch and flywheel due to the high torque. Member Eggman can vouch for that. 192.168.100.1 192.168.1.1 jpg to pdf
I've run my 4bt with a new head gasket and arp studs at 60 psi max for 100,000 kms with zero issues. It can't hurt but I don't think it's gonna be an issue.
If your want to run 300 hp that is a question of where are u measuring that 300 hp. 300 crank hp or 300 wheel hp is very different with big drivetrain components as the are lots of losses.
It's a hot topic but i'm just shy of 300 whp and there is no way you are getting 300 whp on a single turbo let alone that hx30 super. Your gonna need compounds to do that job.
 

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Discussion Starter #7
I've run my 4bt with a new head gasket and arp studs at 60 psi max for 100,000 kms with zero issues. It can't hurt but I don't think it's gonna be an issue.
If your want to run 300 hp that is a question of where are u measuring that 300 hp. 300 crank hp or 300 wheel hp is very different with big drivetrain components as the are lots of losses.
It's a hot topic but i'm just shy of 300 whp and there is no way you are getting 300 whp on a single turbo let alone that hx30 super. Your gonna need compounds to do that job.
I figured 300 at the crank would be fine, really 250 would prolly make me happy. Just seemed like a good number to shoot for.
Are you running a Cummins headgasket of aftermarket? Did you overtorque studs?
Also, which turbos are you running on your setup? I figured I would start with a single and get the truck finished, then figure out compound setup. This is my first full build so I still have a lot to learn, and a lot of cash to spend
 

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I figured 300 at the crank would be fine, really 250 would prolly make me happy. Just seemed like a good number to shoot for.
Are you running a Cummins headgasket of aftermarket? Did you overtorque studs?
Also, which turbos are you running on your setup? I figured I would start with a single and get the truck finished, then figure out compound setup. This is my first full build so I still have a lot to learn, and a lot of cash to spend
When I did my long block my engine machinist waited to see the actual head gasket I would run before he surfaced the block/head, he was adamite about that saying that in his experience the surface finish required was dependent on which style gasket would be used.
If I were you I'd build the long block for compounds when I did it, it's not a big cost difference and would serve you well in the long run even with a high HP single build.
Go with a high volume oil pump I used one for a 24 valve IIRC also the 6 cyl oil cooler another cheap item would be high flow piston cooling nozzles. The big oil pump will keep the oil pressure at normal levels when feeding two turbos and the bigger nozzles and more cooler will help with the added heat load from cooling the second turbo as well as the added heat from each piston when running it hard. another thing I had to upgrade was the boots on at a minimum the hot side of the intercooler Vibrant makes straight boots that have either Nomex or Kevlar reinforcement instead of polyester thus raising the working temp to *500 vs *400, I was having issues with hot side boots in the summer when the near *400 charge air temps and the *250 engine compartment temps were too much for the polyester to cope with the 40PSI boost the extra *100 of operating temp has made the difference and they have been reliable with 40PSI + this summer.
 
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When I did my long block my engine machinist waited to see the actual head gasket I would run before he surfaced the block/head, he was adamite about that saying that in his experience the surface finish required was dependent on which style gasket would be used.
If I were you I'd build the long block for compounds when I did it, it's not a big cost difference and would serve you well in the long run even with a high HP single build.
Go with a high volume oil pump I used one for a 24 valve IIRC also the 6 cyl oil cooler another cheap item would be high flow piston cooling nozzles. The big oil pump will keep the oil pressure at normal levels when feeding two turbos and the bigger nozzles and more cooler will help with the added heat load from cooling the second turbo as well as the added heat from each piston when running it hard. another thing I had to upgrade was the boots on at a minimum the hot side of the intercooler Vibrant makes straight boots that have either Nomex or Kevlar reinforcement instead of polyester thus raising the working temp to *500 vs *400, I was having issues with hot side boots in the summer when the near *400 charge air temps and the *250 engine compartment temps were too much for the polyester to cope with the 40PSI boost the extra *100 of operating temp has made the difference and they have been reliable with 40PSI + this summer.
Dang, I wasn’t aware of the high flowcooling nozzles! Now my crank and pistons are in and I would hate to go back and redo the work. Will the standard get the job done?

I appreciate the info! Tried to overbuild for future power goals but obviously don’t know everything that included.

Also, would you run an aftermarket cam? I have read everything I can find, but have not seen a dyno print. Just measured piston protrusion (.032”), and need to figure out cam/head gasket ASAP.
 

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My cam was in questionable condition so i did kick around that option, I decided to go with the factory cam my thinking after a little research was that since I really wanted to keep the torque curve where it was. With the compounds it just runs like a strong 6 cylinder and is still happiest between 1,500 and 2,000 and by 2,250 or so the torque curve has flattened out and is starting to drop.
 
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Also, would you run an aftermarket cam? I have read everything I can find, but have not seen a dyno print.
That's because the hp gain would be approx 6hp for a 4bt performance cam. We were the 1st company back in the day to supply to the masses a performance camshaft for the Cummins. For the 6bt the gain was 10hp on average & the 4bt was 6hp. As eggman says, unless you want to move your hp/torque curve to a different rpm, stick with the stock cam.
 

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That's because the hp gain would be approx 6hp for a 4bt performance cam. We were the 1st company back in the day to supply to the masses a performance camshaft for the Cummins. For the 6bt the gain was 10hp on average & the 4bt was 6hp. As eggman says, unless you want to move your hp/torque curve to a different rpm, stick with the stock cam.
Thanks! Factory cam is in great shape so I will stick with it. Would you happen to know if .032” piston protrusion will have clearance issues? I know factory max is .028” and I will have to check anyways, but I would rather have the right head gasket before I get that far
 

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Thanks! Factory cam is in great shape so I will stick with it. Would you happen to know if .032” piston protrusion will have clearance issues? I know factory max is .028” and I will have to check anyways, but I would rather have the right head gasket before I get that far
Clearance issues with standard gasket that is*
 

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The measurement you really need is between top of piston & the valves. Bare min of 60 thou.
Piston protrusion means squat if the cyl head has been re-surfaced & valves weren't recessed further into cyl head. Your dealing with a unknown ( used engine with no history data ) so check your clearance between pistons & valves to determine which gasket you use.
BTW, I personally wouldn't use any other gasket than a Genuine Cummins, but that's just me.
 

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The measurement you really need is between top of piston & the valves. Bare min of 60 thou.
Piston protrusion means squat if the cyl head has been re-surfaced & valves weren't recessed further into cyl head. Your dealing with a unknown ( used engine with no history data ) so check your clearance between pistons & valves to determine which gasket you use.
BTW, I personally wouldn't use any other gasket than a Genuine Cummins, but that's just me.
Cylinder head is new and valves are recessed .065”. I have a Cummins upper gasket set, But I only have so long to exchange it. Just curious if to tolerances were known to work, guess I need to hurry up
 

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I figured 300 at the crank would be fine, really 250 would prolly make me happy. Just seemed like a good number to shoot for.
Are you running a Cummins headgasket of aftermarket? Did you overtorque studs?
Also, which turbos are you running on your setup? I figured I would start with a single and get the truck finished, then figure out compound setup. This is my first full build so I still have a lot to learn, and a lot of cash to spend
Oem Cummins head gasket. Just torque everything to spec.
To start out, break your engine in with a small turbo and then go from there. If your not familiar with b series Cummins engines I wouldn't start out with a full out build. Get her running first with a basic set up and then start building
Do some reading on the forum here about turbo set ups but if you want 300 hp your gonna need compounds or it will be undriveable with the necessary fuel. Depending on how you build your engine you will want different turbos, it's not a cookie cutter set up for every engine when I comes to turbos.
I can't say I've run my engine without a stage 3 cam, but it spools an hx35 dam good and keeps the egts down. From what I've heard it keeps egts down as well as giving a bit more hp. With an hx35 and small injectors and basic pump mods I made 478 flt lbs and 208 hp, If that's not low end power I don't know what is.
 

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My suggestions:
1. Keep stock injectors. Rebuild them if you want, but keep em stock until you do compounds.
2. Run a HX30w, super or not. You will not want a HX35 as a single on the street, certainly not with a stock cam. I've been very happy with my Super HX30w.
3. Replace the head gasket if only to inspect the cylinder bores. Install with ARP studs if you intend to put compounds in at some point in the future.
4. Run a ~3800rpm governor spring. I don't go above 3200rpm often (3200rpm spring is the next lower one for a VE), but when I do, I'm sure glad I can.
5. Run 60# valve springs.
 
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