Complete re-build of head questions

[punkzdriver]

I am looking at purchasing a used S13 SR20DET head to use for a custom build. I am looking to build the head with the following components:
BC +1 intake and BC +1 exhaust valves
BC spring retainers
BC valve guides for the +1 valves
Supertech valve seals
Tomei Type-A springs
Tomei Poncams
Tomei rocker keepers
All other parts OEM...cam gears, HLAs, rocker arms etc.

I am also looking to have the head sent to a machine shop to be cleaned, measured, and have a valve job done to fit/install the valve guides and valves.

My question is regarding the re-assembly using all new components. I know typically all parts, nuts, bolts, caps, shims, etc. are carefully recorded so that they can be placed in the same location. But, if I am starting with almost all new parts, how do I go about shimming everything?

[Prok0]

You would want a skilled machine shop to install valves, measure and cut tip height so they are all more or less the same height, install your valves/springs/retainers/etc and then with specialty tools you would need to measure the valve tip height and order/install shims accordingly.

We had made a piece back in the day out of some billet aluminum that was placed on the top of the head, and had holes machined at the same angle as the valves and you would drop two dial gauges in it to determine tip height of both valves on one side of the camber

[jr_ss]

IMO, dumping that kind of money into a DET head is just silly. Why spend thousands of dollars to polish a turd? A VE head is much more capable than the DET head, even in stock form and only costs a couple Gs more to get up and running. Invest in future growth.

[KAT-PWR]

If you're doing cams you should have recieved a cam card that specifies the tolerances. I'm not familiar with the SR but in KA heads there is a shim on top of the bucket, you slide feeler gauges to check tolerance and record for all valves. Then you measure your shims and based on the clearance order the shim from Nissan of the proper thickness to give you your target clearance. This is very tedious work
Although you can just drop cams in and see benefit you will really benefit most from a set of adjustable cam gears and degreeing them in properly for maximum benefit.

[punkzdriver]

IMO, dumping that kind of money into a DET head is just silly. Why spend thousands of dollars to polish a turd? A VE head is much more capable than the DET head, even in stock form and only costs a couple Gs more to get up and running. Invest in future growth.

Engine is going in a Datsun Roadster. To make the VE head work, there is additional body modifcation required. Also, I want to use the Tomei 4throttle ITBs because I like what they provide from both a performance standpoint AND how they complete the old school look. From people that have used them on a VE head, the tuning is much more than I want to do.

Call me silly, and spending money on a DET head...but I am also going to use the DET head and block (stroking it) in a Naturally Aspirated set up. So I am beyond silly...but those my plans

[punkzdriver]

If you're doing cams you should have recieved a cam card that specifies the tolerances. I'm not familiar with the SR but in KA heads there is a shim on top of the bucket, you slide feeler gauges to check tolerance and record for all valves. Then you measure your shims and based on the clearance order the shim from Nissan of the proper thickness to give you your target clearance. This is very tedious work
Although you can just drop cams in and see benefit you will really benefit most from a set of adjustable cam gears and degreeing them in properly for maximum benefit.

Using poncams for a relatively drop-in set up. Im not looking for high hp numbers. This is going in a Datsun Roadster. With the car being as light as it is, I dont need that much horsepower. And with the car being as thin as it is, I dont want that much hp. But looking to get the most I can out of an NA set-up.

[KAT-PWR]

Using poncams for a relatively drop-in set up. Im not looking for high hp numbers. This is going in a Datsun Roadster. With the car being as light as it is, I dont need that much horsepower. And with the car being as thin as it is, I dont want that much hp. But looking to get the most I can out of an NA set-up.

If you're N/A you especially want cam gears because there are less gains on the table.

[Kingtal0n]

I never recommend adj cam gears on engines that have oil soaked gears (like the sr20). It simply takes too long to get under the valve cover, make adjustments, run the engine again, rinse and repeat.

There is also a chance they could come loose.

If the engine is open face, like an RB or something, then you could get away with it. But its still a huge PITA to tune them (gota be done on a dyno. Run the car, make adjustment, run the car, repeat. Puts alot of wear and tear on the engine too).

I just never liked that about them. If you need to squeeze every last drop of power out of something... you really have no choice but to use every available option. But there are at least 20 better uses of $$ and 20 other easier ways to increase power out put as well.

[punkzdriver]

If you're N/A you especially want cam gears because there are less gains on the table.

Understood, but again, Im not looking to make freakish numbers. I am under the impression that the poncams are good with stock cam gears. Im not sure if I like all of the extra (possible) moving parts with the adjustable cam gears for what I would get out of them. The solid JWT cam gears on the other hand might be appealing

[vipergtsr1000hp]

If you are going for a N/A setup, I highly recommend converting to the VE head. Most preferably the P12 as it has the CAS and a single solenoid. This allows it so you don't have to buy a solenoid relocation block. IDK how the motor would sit in your car, but I think it would work. You would save a ton of money going VE than building your head i.e. won't have to go to a machine shop that might fuck shit up, labor, etc. Just keep the head stock and you will definitely make more power. P12 cams are 280 stock, more than what you can get from a DE head. A complete P12 motor w/ trans can be had from ebay for $1500-2000. You can use the same oil pump from the motor as the P12 pump is stronger than the older P11 (different part number and hard to find). Just bring your block to a well reputable machine shop to block the oil drain port, shave the block with the pump, and your block is good to go for the VE head. Do some research on VE head swaps and decide. You won't have to worry about spitting shims or breaking rocker arms with the VE!

[Kingtal0n]

Naturally aspirated 4-cylinders are not "performance engines" or should not be used for performance related acitivity... unless you simply desire it for a personal reason... there is nothing really high performance about them except the additional difficulty and maintenance troubles associated with aftermarket parts in general.

Consider a 350 horsepower V8 engine will run you $500 to $1000 and it will also go 150,000 miles reliably.

You may spend five to twenty times more cash generating a "performance" 4-cylinder with less than half the output... $$ to HP ratio is the worst, just awful.

[jr_ss]

Naturally aspirated 4-cylinders are not "performance engines" or should not be used for performance related acitivity... unless you simply desire it for a personal reason... there is nothing really high performance about them except the additional difficulty and maintenance troubles associated with aftermarket parts in general.

Consider a 350 horsepower V8 engine will run you $500 to $1000 and it will also go 150,000 miles reliably.

You may spend five to twenty times more cash generating a "performance" 4-cylinder with less than half the output... $$ to HP ratio is the worst, just awful.

Dude, STFU. He obviously has a goal in mind. You preach this bullshit all the time, no one cares what you think. There are hundreds of performance oriented 4 cylinder engines racing all across the country.

I think a 1.6, 1.8, 2.0 or any modern 4cyl engine producing 250+ hp naturally aspirated is doing something right. What does you V8 produce NA hp/liter? Not nearly what these 4cyl engines are. Sure reliability plays a part, but racing an NA V8 in an unlimited class (the class you'd be in because it's not a factory engine) isn't going to get you anywhere.

[Kingtal0n]

Dude, STFU. He obviously has a goal in mind. You preach this bullshit all the time, no one cares what you think. There are hundreds of performance oriented 4 cylinder engines racing all across the country.

I think a 1.6, 1.8, 2.0 or any modern 4cyl engine producing 250+ hp naturally aspirated is doing something right. What does you V8 produce NA hp/liter? Not nearly what these 4cyl engines are. Sure reliability plays a part, but racing an NA V8 in an unlimited class (the class you'd be in because it's not a factory engine) isn't going to get you anywhere.

Thats a personal reason. Also, the sr is not a factory engine. So... yeah not sure what you meant.

$$ per horsepower was my only point/issue. And its true...

[jr_ss]

Thats a personal reason. Also, the sr is not a factory engine. So... yeah not sure what you meant.

$$ per horsepower was my only point/issue. And its true...

The SR is a factory engine, sure we didn't get it, but many other countries did. However, I wasn't specifically talking about S-chassis and SRs, I was including the gamut of 4cyl vehicles.

[punkzdriver]

If you're N/A you especially want cam gears because there are less gains on the table.

If going with adjustable cam gears, does the drive gear from the exhaust cam sprocket get removed and used on the new cam gear? I wasnt sure if that part was removable

[punkzdriver]

Naturally aspirated 4-cylinders are not "performance engines" or should not be used for performance related acitivity... unless you simply desire it for a personal reason... there is nothing really high performance about them except the additional difficulty and maintenance troubles associated with aftermarket parts in general.

Consider a 350 horsepower V8 engine will run you $500 to $1000 and it will also go 150,000 miles reliably.

You may spend five to twenty times more cash generating a "performance" 4-cylinder with less than half the output... $$ to HP ratio is the worst, just awful.

There are a number of reasons why I have plans to stay NA and not use the VE head. I have explained it in other posts, but since I am new to this engine, trying to learn, I appreciate any and all feedback.

The engine is going in a 1967.5 Datsun Roadster. SR20 swaps in this platform have become quite common and there are many parts made specifically for the swap as are LS1 swap parts for the 240sx.

The car weights under 2000lbs, so I dont need a lot of power to make the car do what I want. Also, the car is from the sixties, and very thin. Having gobs of power could be stupid. Running a turbo requires additional body modification to make fit. That isnt the biggest deal as a KA is relatively straight drop in, while the SR does take some frame modification. Also, the VE head requires additional body to make fit as well. My goal is also to use the Tomei ITB set-up for both the look, fits the classic look, and provides NA performance. That part is designed for the S13 head. So yeah the $$ - hp ratio isnt ideal for what I am looking for. But its my build, I will do what I want. But I do want to get as much out of the engine as possible (also going BC stroker kit) and is why I am re-doing the head. More fuel from stroker, more air from ITBs, want the head to make it all work.

[jr_ss]

If you haven't bought the stroker or ITB setup yet, don't. You can save yourself so much money by doing a VE head swap. You can still use the Tomei ITBs but you'll make more power with a stock bottom end, which will be more reliable and parts are easier to come by.

I'm not trying to sway your interest, but a Stroker kit is a waste for NA power goals. You want the "most" from your setup, take a step back and do some research. Stock VE motors are known to push out 2-225whp with cams exhaust and some tuning.. You'll be lucky to break 200whp with all the money your getting ready to dump into a DET motor setup.

[Kingtal0n]

More fuel from stroker, more air from ITBs, want the head to make it all work.

Ok I want to help you with your personal reason for staying naturally aspirated.

1. no stroker (reliability issue with cylinder walls for starters, plus machine work nobody will do right)
2. no ITB (better ways to spend money)
3. no fancy head swaps (better ways to spend money... to make more power, which you claim you do not want)

The stroker kit would do the same thing as a turbo kit, minus about 100-400 worth of head room of power. You say power isn't an issue yet you are trying to stroke the motor etc... it doesn't make sense. Decide if you want power or economy. If you want power, you MAKE a turbo fit (rear mount if you have to), and use a mostly stock engine up to the OEM piston limit. If you want reliability you do the same thing without a turbo. And if you want more than the OEM piston limit you upgrade the displacement (its cheaper to go to a larger engine than to build an sr20det to withstand what a larger engine with OEM pistons will make)


And last to tie this up with a neat little bow,
If you keep the OEM engine reliable and do not open it (ideal for N/A setup) and want a little more power that it can handle, install a progressive 30-80 shot of nitrous.

[Kingtal0n]

this
but since I am new to this engine, trying to learn,

plus this,

But I do want to get as much out of the engine as possible (also going BC stroker kit) and is why I am re-doing the head. More fuel from stroker, more air from ITBs, want the head to make it all work.

Is a recipe for this:
the car will sit for month(s) while you build everything up, then finally when the machine shop is finished and you get it installed, you will have 8 different issues crop up from strange noises to weird leaking spots on the engine, the machine shop will shrug their shoulders at you, and a couple weeks/months later the motor will fail, and we will never see you again.


Instead, using my 15 years of experience with these situations, I recommend this:
Install a mostly stock engine, mostly stock. keep a spare on the side (using the money you saved), and it is also stock. use nitrous to make up for it's shortcomings, since it is cheap, and effective.

[punkzdriver]

I appreciate everyone's thoughts, opinions, and mostly advice. I agree, I am new to the engine, but I am not new to cars, modding, or my platform.

Im not sure if anyone who had provided advice has experience with the SR20 swap into a Datsun Roadster. There are particular issues that have to be dealt with, I am well aware of, and have discussed with two of the most experienced shops when it comes to this swap. I have also discussed my plans with a prominent shop here on the east coast that builds 240s and has also complete SR20 into Datsun Roadster swaps. I have discussed many common issues with these shops, and have tossed around different build ideas. One idea was to source an Autech engine and be done with it. Problems there are is that they are rare, the exhaust manifold hits the Roadster's steering column, and the 6 speed tranny requires additional tranny tunnel removal. Another idea was to go with the VE head on an S14 long block. Thats one of the best options, but tuning the ITBs on the VE can be a PITA. There is a Roadster owner in the southwest that has that set-up now and it took a long time to get there. The cheapest/easiest option is to just throw a plain jane SR20DE motor in there (and even easier a KA), but I know I would want more out of it. This is a build I want to do ONCE. I have plenty of time, so dont mind waiting for it to be completed. I turn 40 in 2 years, and the swap is going to be a gift to myself. The shop/builder here on the east coast I am very confident and comfortable with, and will have them do a lot of the engine work and build. I just feel knowing as much as I can, and being able to do as much as I can will help me and the process along the way.
And again...I dont want to go turbo, even though its best bang for the buck, for a few reasons. Nitrous isnt my cup of tea either.

I appreciate all of the advice, its why I am here.

[Kingtal0n]

The sr20 is not easy to assemble correctly

SRs that built and failed quick

http://zilvia.net/f/showthread.php?t=535520
http://zilvia.net/f/showthread.php?t=569861
http://zilvia.net/f/showthread.php?p=5765974
http://zilvia.net/f/showthread.php?t=579996
http://zilvia.net/f/showthread.php?t=586960
http://zilvia.net/f/showthread.php?t=415523&page=2
http://zilvia.net/f/showthread.php?p=5951668#post5951668

I am trying to save you the heartache of machine work gone wrong, which not only ruins the engine, it wastes all the time and parts you brought together for it, and for nothing. An OEM bottom end on an sr20det engine will hold 300rwhp, far more than you could even hope to produce with an N/A engine. you could use an OEM sr20det bottom end and go N/A with the top, however at just 8.5:1 that would be silly and I am not sure how much more you can get out of it with just a chamber mod, I never tried. On an N/A engine your best friend is compression and high octane; you will want E85, NO QUESTION about that, a single walbro will be fine since you are sub 250rwhp, and 11 or 12:1 compression would be ideal, I never tried this so I don't know where you want to stop, I just know the more you can get away with the better (compression).

machine work is an enormous hassle and feels like rolling the dice. I avoid machine work if at ALL possible, and if I can have 550rwhp from an OEM engine for 150,000 miles without ANY machine work in my application, you should be able to make baby power without it in yours. Wouldn't you feel silly if it falls apart in 3 years / 17,000 miles with a $5000 bottom end, when a $500 bottom end is still going for 12+ years with twice the power? Im not trying to save you hundreds, I am trying to save you thousands of dollars and minutes. There are V8 engines that weigh about the same as the sr20 with rock solid OEM bottom ends. You could always put a bolt under the gas pedal if the extra power bothers you!