CA18DET rebuild opinions

Hi Guys

So it turns out I do not in fat have a noisy lifter, after changing all 16 it seems the sound is still there. So it is either a piston slap or small end bearing, not sure which as it still bloody sounds like a lifter. But engine the engine must come out and be opened.

For you guys that don't know, it is running stock bottom end with bolt ons and was making 200RwKw with Meth and controlled by Wolf 3D ECU. Now since I am opening the motor I will be fitting Cometic head gasket, ARP studs and CP pistons. Bearings will obviously be replaced as well.

Now I have a 20 year plan for the SX, it need to be reliable as possible. My original goal for the car was to build the car Nissan should have, so it must have smooth power delivery and drive like any OEM car, huge strong boost is out of the question. Current TD04 turbo is probably almost maxing out at the current flow levels but that is fine because I have 1 Bar from 2800rpm (OEM like see...). No fancy fuels or octane boosters can be used.

Question is should I go 9:1 or 9.5:1 compression ratio, considering I won't be running over a bar?? Also while the motor is open should I go Forged rods as well? Or should I just fit new ARP rod bolts? I know at the power levels I will be running the stock rods will be more than ample but the motor must run for 20 years and head rood is a wonderful thing (read up, reliability). How effective is shot peening 20 year old rods, is it worth it? How much does it cost, considering ARP rod bolts are $60 and new rods are $360.

Just throw around your opinions guys and lets see if I can make my mind up.

PS: I love my car (no really I do, don't laugh) so reusing as many of my original parts is important to me. No SR20 swap ideas please DriftZ, if I wanted a tractor engine I would a Massey Fergusen ride on lawn mower.

Cheers Guys
Gary

i think you might have a knock on your door mine sounded like a lifter but was a knock. if you going forged why not boost a bit higher 1.4 or so?

Doesn't act like a big end bearing knock. If you talking about DET nope certainly not that. Possibly a small end or the start of piston slap.

I am not after silly power figures, and 1.4bar would require bigger turbo and in turn more lag etc, not what I want.

I don't mind boosting to what current turbo can take as it give a good linear drive so has the right characteristics I am looking for. I was think 1-1.1bar with a 9:1 CR should be plenty of power. Should be a fair bit over 200 at the wheels.

Hi Gary

My motor had that exact problem with the small end, hence the reason why i rebuilt my motor.

Stock is around 8:5, if you want to be safe 9:1 would be a good choice, but if you are going to run 1 bar and the meth the 9.5:1 would make is much more responsive especially at the lower revs. You may be able to turn down the boost for the same Hp figures you are running now on 1 bar. I am personally planning to run at 9.0:1.

The Arais pistons, arent to bad. I bought 2 sets before. Just ensure the engineering firm has the tolerances to spec should they rebore. They are around R5500- R5800 a set. The ones i received has a dish of -6 cc's, which seems they are made to either be able to support hugh lifting cams or be "free running" in case the cam belt snaps. :200sx_2guns:

Shot peening is expensive; I don’t really think it’s worth it. I replaced my rods with some of the Mr Turbo rods, i was skeptical at first but there are a couple of high powered turbo cars running around sporting the Mr turbo rods, the stock rods aren’t to bad either and should also be able to handle the power. I know of guys who ran Ca18det's on over 1.5 bar boost and 400whp with the stock rods. If you do get the Mr Turbo rods, they do not have sprays in them as per the stock rods, so make sure your DET oil sprays aren’t clogged or it will seize the rings in the sleeves.

With regards to your bottom end, I found there is a scarcity on the bearings!!! i would take the crank to be measured and ask the engineering firm to supply the bearings, this would ensure you have good oil pressure. Make sure to get lead copper bearings, if not get some ACL bearings, (I used the regulars ACL bearings on my big ends and the racing bearings on the rods). If you use a good engineering shop they will be able to make sure your tolerances are good within spec and ready to go. Also maybe consider asking them to check the balancing of the crank. My CA18det crank came right out of a new import and they needed to correct it by quite a bunch ( Requested to be low speed balanced and high speed to 10 000rpms @ Fullrace)

If you are going to work on the bottom end, then just keep in mind the front timing gear on the crank is a @#$#@$ to get off!!!! Try to source one beforehand in case, Nissan asks around R350 i think for a new one.

Also make sure to check your head, make sure the valve guides are still fine and the valve seats arent leaking. I found some of mine to be leaking and the guides to be faulty (after i did the head over at Cylinder head services about a year ago, with the car running less than 3000kms the last year.

On the head side, I also replaced my studs with ARP, but to be honest for your goals they might be over kill. Just get a gooood quality head gasket like a cometic. On the exhaust gasket side, have a look at the cometic steel exhaust gaskets. The material gaskets tend to leak because they set as they seat it seems you need to retighten the bolts now and again.

I also chose to replace the oil pump +- R1400, GMB water pump R350, Tensioner bearings +- R550 ans)

Keep the CA18, there have been heavy pointless debates, most based on internet rantings, personal feelings, heresay and speculating thoughts, at the end of the day both motors are old and needs a refresh if you are planning on gunning it, The Sr20s are also prone to throw a bearing if you do not take very good care of it, both of these motors are expensive to replace, i know this because i have had both. The ca18 lacks the cc’s which is esspecially noticeable at the bottom end due to the head design, but the power delivery is up there with the sr20det on higher rev’s. Most people do ridiculous comparing equations, like to compare the motors stock for stock (Different turbo sizes, management differences ans), In the end they are designed to be different, the ca is a motor which is built to rev hence the big 4 ports, unless you would like more bottom end power then the 8 port would suit you. With EXACTLY the same mods the CA18’s seem to be effective and punchy, for the price of the conversion to a sr20 the monies rather spent on a proper ca18 is worth it, saw a vid of a Jap running almost 9 flats with a ca18 the other day and there have been a couple of local guys running powerful ca18dets which include cars running in the 10’s on the ¼ mile @ over 200km/h and 240km/h+ on the 800!!! (at reef)

Check out my thread.... Or you can just buy my motor R45 000 (Will throw in gasket maker for assembly and oil, and a double racing clutch and custom flywheel. Prce is excluding turbo ans... 😁 :domo: :200sx_ban:

double post

Grobblere wrote:

Hi Gary

My motor had that exact problem with the small end, hence the reason why i rebuilt my motor.

Stock is around 8:5, if you want to be safe 9:1 would be a good choice, but if you are going to run 1 bar and the meth the 9.5:1 would make is much more responsive especially at the lower revs. You may be able to turn down the boost for the same Hp figures you are running now on 1 bar. I am personally planning to run at 9.0:1.

The Arais pistons, arent to bad. I bought 2 sets before. Just ensure the engineering firm has the tolerances to spec should they rebore. They are around R5500- R5800 a set. The ones i received has a dish of -6 cc's, which seems they are made to either be able to support hugh lifting cams or be "free running" in case the cam belt snaps. :200sx_2guns:

Shot peening is expensive; I don’t really think it’s worth it. I replaced my rods with some of the Mr Turbo rods, i was skeptical at first but there are a couple of high powered turbo cars running around sporting the Mr turbo rods, the stock rods aren’t to bad either and should also be able to handle the power. I know of guys who ran Ca18det's on over 1.5 bar boost and 400whp with the stock rods. If you do get the Mr Turbo rods, they do not have sprays in them as per the stock rods, so make sure your DET oil sprays aren’t clogged or it will seize the rings in the sleeves.

With regards to your bottom end, I found there is a scarcity on the bearings!!! i would take the crank to be measured and ask the engineering firm to supply the bearings, this would ensure you have good oil pressure. Make sure to get lead copper bearings, if not get some ACL bearings, (I used the regulars ACL bearings on my big ends and the racing bearings on the rods). If you use a good engineering shop they will be able to make sure your tolerances are good within spec and ready to go. Also maybe consider asking them to check the balancing of the crank. My CA18det crank came right out of a new import and they needed to correct it by quite a bunch ( Requested to be low speed balanced and high speed to 10 000rpms @ Fullrace)

If you are going to work on the bottom end, then just keep in mind the front timing gear on the crank is a @#$#@$ to get off!!!! Try to source one beforehand in case, Nissan asks around R350 i think for a new one.

Also make sure to check your head, make sure the valve guides are still fine and the valve seats arent leaking. I found some of mine to be leaking and the guides to be faulty (after i did the head over at Cylinder head services about a year ago, with the car running less than 3000kms the last year.

On the head side, I also replaced my studs with ARP, but to be honest for your goals they might be over kill. Just get a gooood quality head gasket like a cometic. On the exhaust gasket side, have a look at the cometic steel exhaust gaskets. The material gaskets tend to leak because they set as they seat it seems you need to retighten the bolts now and again.

I also chose to replace the oil pump +- R1400, GMB water pump R350, Tensioner bearings +- R550 ans)

Keep the CA18, there have been heavy pointless debates, most based on internet rantings, personal feelings, heresay and speculating thoughts, at the end of the day both motors are old and needs a refresh if you are planning on gunning it, The Sr20s are also prone to throw a bearing if you do not take very good care of it, both of these motors are expensive to replace, i know this because i have had both. The ca18 lacks the cc’s which is esspecially noticeable at the bottom end due to the head design, but the power delivery is up there with the sr20det on higher rev’s. Most people do ridiculous comparing equations, like to compare the motors stock for stock (Different turbo sizes, management differences ans), In the end they are designed to be different, the ca is a motor which is built to rev hence the big 4 ports, unless you would like more bottom end power then the 8 port would suit you. With EXACTLY the same mods the CA18’s seem to be effective and punchy, for the price of the conversion to a sr20 the monies rather spent on a proper ca18 is worth it, saw a vid of a Jap running almost 9 flats with a ca18 the other day and there have been a couple of local guys running powerful ca18dets which include cars running in the 10’s on the ¼ mile @ over 200km/h and 240km/h+ on the 800!!! (at reef)

Check out my thread.... Or you can just buy my motor R45 000 (Will throw in gasket maker for assembly and oil, and a double racing clutch and custom flywheel. Prce is excluding turbo ans... 😁 :domo: :200sx_ban:

Hi Grobblere

Thanks for your vey detailed post.

Do you not think 9.5:1 will be very prone to DET, I know modern cars are high CR boosted units but I think they have a better detailed head to combat the DET?! What CR did you opt for?

I am going to go for CP pistons as I want it to be quiet when cold, they aren't badly priced at $520. I assume to get 9:1 the CPs must be domed. What did you pay for the Mr Turbo rods? Do you know the weight of the stock rods vs Mr Turbo rods?

The bearings, I will run is OEM if the crank is still in spec, these have lasted 140 000km since last rebuild, if not the I will use ACL, probably not Race series as it needs to run for 20 more years and that is not what the Race series is designed for.

At the last rebuild it was dynamically balanced and the fly wheel lightened extensively so I should be good in that department.

Sad thing about this is the engine has just been put back in to change the oil pump, this is why I am so bummed. Anyway I fitted a new OEM oil pump, as well as 6 out if the 16 new lifters are new OEM as well. I will change 2 more to OEM now with he rebuild and the oth 8 when I the funds allow,no rush for them as long I have them on my shelf I happy.

I will definitely replace head bolts to ARP,I have retorqued he head numerous times,stock gaskets and bolts just aren't up to the task for the power I was running.

Will inspect water pump as well, might replace with OEM if needed. Won't go pirate parts at all as I am dead Serious about 20 years of driving.

I think the CA is a brilliant engine, far better head design than the SR20, only reason SR is "better" is parts are cheaper and more readily available and the 200 odd more CCs help with power.

As I said I love my car so using as many original parts is important, thanks for the offer but no I will rather build my own engine.

Grobblere wrote:

Hi Gary

My motor had that exact problem with the small end, hence the reason why i rebuilt my motor.

Stock is around 8:5, if you want to be safe 9:1 would be a good choice, but if you are going to run 1 bar and the meth the 9.5:1 would make is much more responsive especially at the lower revs. You may be able to turn down the boost for the same Hp figures you are running now on 1 bar. I am personally planning to run at 9.0:1.

The Arais pistons, arent to bad. I bought 2 sets before. Just ensure the engineering firm has the tolerances to spec should they rebore. They are around R5500- R5800 a set. The ones i received has a dish of -6 cc's, which seems they are made to either be able to support hugh lifting cams or be "free running" in case the cam belt snaps. :200sx_2guns:

Shot peening is expensive; I don’t really think it’s worth it. I replaced my rods with some of the Mr Turbo rods, i was skeptical at first but there are a couple of high powered turbo cars running around sporting the Mr turbo rods, the stock rods aren’t to bad either and should also be able to handle the power. I know of guys who ran Ca18det's on over 1.5 bar boost and 400whp with the stock rods. If you do get the Mr Turbo rods, they do not have sprays in them as per the stock rods, so make sure your DET oil sprays aren’t clogged or it will seize the rings in the sleeves.

With regards to your bottom end, I found there is a scarcity on the bearings!!! i would take the crank to be measured and ask the engineering firm to supply the bearings, this would ensure you have good oil pressure. Make sure to get lead copper bearings, if not get some ACL bearings, (I used the regulars ACL bearings on my big ends and the racing bearings on the rods). If you use a good engineering shop they will be able to make sure your tolerances are good within spec and ready to go. Also maybe consider asking them to check the balancing of the crank. My CA18det crank came right out of a new import and they needed to correct it by quite a bunch ( Requested to be low speed balanced and high speed to 10 000rpms @ Fullrace)

If you are going to work on the bottom end, then just keep in mind the front timing gear on the crank is a @#$#@$ to get off!!!! Try to source one beforehand in case, Nissan asks around R350 i think for a new one.

Also make sure to check your head, make sure the valve guides are still fine and the valve seats arent leaking. I found some of mine to be leaking and the guides to be faulty (after i did the head over at Cylinder head services about a year ago, with the car running less than 3000kms the last year.

On the head side, I also replaced my studs with ARP, but to be honest for your goals they might be over kill. Just get a gooood quality head gasket like a cometic. On the exhaust gasket side, have a look at the cometic steel exhaust gaskets. The material gaskets tend to leak because they set as they seat it seems you need to retighten the bolts now and again.

I also chose to replace the oil pump +- R1400, GMB water pump R350, Tensioner bearings +- R550 ans)

Keep the CA18, there have been heavy pointless debates, most based on internet rantings, personal feelings, heresay and speculating thoughts, at the end of the day both motors are old and needs a refresh if you are planning on gunning it, The Sr20s are also prone to throw a bearing if you do not take very good care of it, both of these motors are expensive to replace, i know this because i have had both. The ca18 lacks the cc’s which is esspecially noticeable at the bottom end due to the head design, but the power delivery is up there with the sr20det on higher rev’s. Most people do ridiculous comparing equations, like to compare the motors stock for stock (Different turbo sizes, management differences ans), In the end they are designed to be different, the ca is a motor which is built to rev hence the big 4 ports, unless you would like more bottom end power then the 8 port would suit you. With EXACTLY the same mods the CA18’s seem to be effective and punchy, for the price of the conversion to a sr20 the monies rather spent on a proper ca18 is worth it, saw a vid of a Jap running almost 9 flats with a ca18 the other day and there have been a couple of local guys running powerful ca18dets which include cars running in the 10’s on the ¼ mile @ over 200km/h and 240km/h+ on the 800!!! (at reef)

Check out my thread.... Or you can just buy my motor R45 000 (Will throw in gasket maker for assembly and oil, and a double racing clutch and custom flywheel. Prce is excluding turbo ans... 😁 :domo: :200sx_ban:

Hi Grobblere

Thanks for your vey detailed post.

Do you not think 9.5:1 will be very prone to DET, I know modern cars are high CR boosted units but I think they have a better detailed head to combat the DET?! What CR did you opt for?

I am going to go for CP pistons as I want it to be quiet when cold, they aren't badly priced at $520. I assume to get 9:1 the CPs must be domed. What did you pay for the Mr Turbo rods? Do you know the weight of the stock rods vs Mr Turbo rods?

The bearings, I will run is OEM if the crank is still in spec, these have lasted 140 000km since last rebuild, if not the I will use ACL, probably not Race series as it needs to run for 20 more years and that is not what the Race series is designed for.

At the last rebuild it was dynamically balanced and the fly wheel lightened extensively so I should be good in that department.

Sad thing about this is the engine has just been put back in to change the oil pump, this is why I am so bummed. Anyway I fitted a new OEM oil pump, as well as 6 out if the 16 new lifters are new OEM as well. I will change 2 more to OEM now with he rebuild and the oth 8 when I the funds allow,no rush for them as long I have them on my shelf I happy.

I will definitely replace head bolts to ARP,I have retorqued he head numerous times,stock gaskets and bolts just aren't up to the task for the power I was running.

Will inspect water pump as well, might replace with OEM if needed. Won't go pirate parts at all as I am dead Serious about 20 years of driving.

I think the CA is a brilliant engine, far better head design than the SR20, only reason SR is "better" is parts are cheaper and more readily available and the 200 odd more CCs help with power.

As I said I love my car so using as many original parts is important, thanks for the offer but no I will rather build my own engine.

Gary, a very easy way of checking a small end noise is to simply remove the spark from that cylinder while the engine is running.
On my old Alfa`s I would simply pull the plug lead from the cylinder and the noise would go away. Sure sign of a small end bush that`s worn.
What you are in effect doing is taking away the compression load on the small end . No force on the piston, no noise.
COP engines are easy to do. The 3.7 24v Alfa V6 has COP`s and I simply remove the COP , make sure to earth it with a lead a 2x croc clips, fit a loose Bougi cord and bingo.
On off as you please.

BK

Grobb`s , finally someone who has done the work himself. Good stuff.
The new generation ally/ metal bearings are just as good as lead/tin/metal backings. The older bearings ran "Babbit" material but that's been out of use for some time.

I lost an Alfa v6 turbo engine to Ivan`s "Eagle" rods. Made in friggin china. Its a lucky packet if you get rods that will last or will break. Will NEVER use chinese shit again.Too much money down the drain.
My "cheaper" rod of choice nowadays is "Argo" from Ozz. All my export Alfa engines run these as does my Lexus V8 Turbo.

Shot peening components , especially rods that have been prepped and lightened is seriously important. I do believe that this operation, WHEN DONE CORRECTLY, improves the surface strength of the rod.
Being an old Aircraft man myself, I only trust an Aircraft servicing and overhauling facility to do my rods.
If you want the correct specifications on the procedure with the specifications of the shot and surface finish, I can give them to you. It`s being a bit anal but that is the correct surface finish you want to aim for. Only an accredited Aircraft facility will give you this.
Prepare everything your self. I use two large washer with a nut and bolt for the big end and similar smaller washer and bolt and nut for the small end surfaces. Don`t leave it up to the shop to do. Do it yourself knowing it`s done correctly.

Hey, I can chat forever on this topic ! Gary, new water pump, new oil pump, modified and "blueprinted" block, all this adds up to the most perfect motor you can build.
Also simply recon the radiator while your`e at it. Did you know main and secondary oil channels are drilled form opposite ends of the block ??
On a well worked machine the two galleries can shift by as much as 50% where they meet deep inside the block !

Well, thats my 2c worth...

BigKriss wrote:

Grobb`s , finally someone who has done the work himself. Good stuff.
The new generation ally/ metal bearings are just as good as lead/tin/metal backings. The older bearings ran "Babbit" material but that's been out of use for some time.

I lost an Alfa v6 turbo engine to Ivan`s "Eagle" rods. Made in friggin china. Its a lucky packet if you get rods that will last or will break. Will NEVER use chinese shit again.Too much money down the drain.
My "cheaper" rod of choice nowadays is "Argo" from Ozz. All my export Alfa engines run these as does my Lexus V8 Turbo.

Shot peening components , especially rods that have been prepped and lightened is seriously important. I do believe that this operation, WHEN DONE CORRECTLY, improves the surface strength of the rod.
Being an old Aircraft man myself, I only trust an Aircraft servicing and overhauling facility to do my rods.
If you want the correct specifications on the procedure with the specifications of the shot and surface finish, I can give them to you. It`s being a bit anal but that is the correct surface finish you want to aim for. Only an accredited Aircraft facility will give you this.
Prepare everything your self. I use two large washer with a nut and bolt for the big end and similar smaller washer and bolt and nut for the small end surfaces. Don`t leave it up to the shop to do. Do it yourself knowing it`s done correctly.

Hey, I can chat forever on this topic ! Gary, new water pump, new oil pump, modified and "blueprinted" block, all this adds up to the most perfect motor you can build.
Also simply recon the radiator while your`e at it. Did you know main and secondary oil channels are drilled form opposite ends of the block ??
On a well worked machine the two galleries can shift by as much as 50% where they meet deep inside the block !

Well, thats my 2c worth...

Hi Barry

Thank for the detailed response.

When I remove the coil plug and kill the spark, the noise goes away but I think it is more the fact of the engine loosing a cylinder and the revs dropping that is causing it. Cause if I rev it the noise is still there. I am almost 90% sure it is a small end but it is difficult to say for certain. My dad is an old Alfa mech and he agrees it is inside but we can't pin down what exactly.

I'll look into the Argo rods, thanks. Have you heard of K1 rods, sold through Wiseco? I think the cost of proper shot peening as you say will be almost the price of new rods.

Radiator is perfect, I fitted it new and its been well maintained and flushed correctly, Mishimoto unit.

I have new Genuine oil pump and will prob fit new OEM water pump while I'm at it. What do you mean "blue printed" this term is thrown around so often by every Charo in DBN who drives a Golf, it could mean anything.

I will do port matching on the intake manifold while its off, would love to send for extrude honing but still can't find anyone who does that.

What do you think of the compression ratio debate, 9:1 or 9.5:1? I will also match the cylinder squish volume to ensure all cylinders have the same dynamic compression ratio. I will also be fitting a Tomie adjustable intake pulley to dial in a few extra degrees to get the mid range up.

Any other old school tips I should do while motor is out?

Gary, you answered your own question. When the spark was removed, the noise went away. It will , at revs, come back as you now have a rather heavy piston and rod to content with.

Yes, the term "Blue printing" is as charo as it can be. What I'm saying here is inspect , verify and correct factory machining and assembly problems while you are at it.
The oil ways ? One half is drilled from the front of the block. It is then swung around and the second , final half is drilled from the back side. When a thousand blocks have been drilled like this the tolerances tend to go awry. Where the two drilled passages meet in the center ? If your block was #1, they would line up perfectly "face to face"
If your block was #1000, those same passages could be so off center , that the two holes don`t line up and diverge where they come together. I had a Chevy cast block that was over lapping my almost 50 %. tHAT MEANS THE SAME OIL VOLUME AS IF THE DRILLED HOLE WAS HALF THE DIAMETER..WELL, NOT QUITE BECAUSE WE ARE TALKING ROUD ORIFICES AND VOLUME VS AREA, BUT YOU GET MY MEANING..

So when on earth did I go to cap locks !!!!!!

As for the comp ratio debate. If the cylinder head chamber, piston shape, inlet track and air supply-remember we are going through an air filter, turbo, piping, inter cooler and throttle body, is highly efficient, the lower CR will do the job handsomely while giving lee way to future added boost.
Cam selection will always play a role here as will the selected LCA which in this case can be adjusted as we have two separate cams. This affects the "dynamic" compression ratio , ie: the ideal "running" CR of the engine.
If you are lucky enough to read or own Ricardo`s book from 1924 regarding his exhaustive thesis on the internal combustion engine, he talks at length about the "dynamic" CR playing a critical role in the efficient working of an engine.
The dynamic CR can alter by the cam selected, the LCA of the cam setup, the CR of the cylinder is changes with every altering of the cam and LCA. That is why in the old days I went to Richie Jute , bought cams for my Alfa, put them in and lost all my races !There is more to an engine build than just cams.

Eish, I`m getting away from myself again..

Nope, never heard of K1, but id bet on them if Wiseco stand behind them.

Its the same as Carillo and CP pistons. Same company, same quality. Good stuff.

Yes, match parting is free everything as it all adds up. And its the proper way to do things..Let me know how the build goes.

BTW, aircraft places are not that expensive, especially if you tell them how good they are and that you only trust their work etc, etc..blow some hot air up the blokes ass. 😀

BigKriss wrote:

Gary, you answered your own question. When the spark was removed, the noise went away. It will , at revs, come back as you now have a rather heavy piston and rod to content with.

Yes, the term "Blue printing" is as charo as it can be. What I'm saying here is inspect , verify and correct factory machining and assembly problems while you are at it.
The oil ways ? One half is drilled from the front of the block. It is then swung around and the second , final half is drilled from the back side. When a thousand blocks have been drilled like this the tolerances tend to go awry. Where the two drilled passages meet in the center ? If your block was #1, they would line up perfectly "face to face"
If your block was #1000, those same passages could be so off center , that the two holes don`t line up and diverge where they come together. I had a Chevy cast block that was over lapping my almost 50 %. tHAT MEANS THE SAME OIL VOLUME AS IF THE DRILLED HOLE WAS HALF THE DIAMETER..WELL, NOT QUITE BECAUSE WE ARE TALKING ROUD ORIFICES AND VOLUME VS AREA, BUT YOU GET MY MEANING..

So when on earth did I go to cap locks !!!!!!

As for the comp ratio debate. If the cylinder head chamber, piston shape, inlet track and air supply-remember we are going through an air filter, turbo, piping, inter cooler and throttle body, is highly efficient, the lower CR will do the job handsomely while giving lee way to future added boost.
Cam selection will always play a role here as will the selected LCA which in this case can be adjusted as we have two separate cams. This affects the "dynamic" compression ratio , ie: the ideal "running" CR of the engine.
If you are lucky enough to read or own Ricardo`s book from 1924 regarding his exhaustive thesis on the internal combustion engine, he talks at length about the "dynamic" CR playing a critical role in the efficient working of an engine.
The dynamic CR can alter by the cam selected, the LCA of the cam setup, the CR of the cylinder is changes with every altering of the cam and LCA. That is why in the old days I went to Richie Jute , bought cams for my Alfa, put them in and lost all my races !There is more to an engine build than just cams.

Eish, I`m getting away from myself again..

Nope, never heard of K1, but id bet on them if Wiseco stand behind them.

Its the same as Carillo and CP pistons. Same company, same quality. Good stuff.

Yes, match parting is free everything as it all adds up. And its the proper way to do things..Let me know how the build goes.

BTW, aircraft places are not that expensive, especially if you tell them how good they are and that you only trust their work etc, etc..blow some hot air up the blokes ass. 😀

Yeah Barry, not quite. The sound goes away or I suspect is masked by the missing sound and the revs dropping. The sound is not there on idle only just off so obviously you pull a coil plug and the rpm drops to idle range and the noise is gone, well it can't be heard anyway.

I have the adjustable intake gear to adjust the dynamic CR to a certain extent, but that is fine tuning. First need to select the static CR, which I am leaning towards 9:1. The stock 8.5:1 is great in boost but since the CA lacks torque because of its 1800cc and I have such a light flywheel the immediate off idle range lacks torque and kind of creates a small flat spot. With the 9:1 it will give more off boost torque and in general greater drivability.

Know any good aircraft machine shops in DBN?

Just weighed a stock rod complete with bolts and nuts, came in at 660g. K1 forged rods are 550g. That is quite a weight saving, think it is a worthwhile investment even if only for the weight saving.

Get some decent rods.

Hi Gary, does yours make the sound even when warmed up, mine suddenly has a knock sound when I just start it but goes away as it warms up, it could just be piston slap but it was never there before, just redid the head and put it back with tomei lifters, suddenly the sound is loud and clear when cold, I want to believe it's piston slap but it's a bother.

Nope mine makes a noise when cold and hot.

Does yours make a sound when old pressure is there, just after start up and then gone, cause could be bearing?

If the sound wasn't there and then all of a sudden came, then something is wrong.

Mine is there when I start it, all the way till it's warmed up, then it goes quiet, it's not there and then suddenly gone, as it warms up and the revs gradually goes up to where it idles when hot, the noise gradually dissapears and I don't hear it again anywhere.

Sounds like a piston slap, bores were probably machined too oversized when rebuilding. Do a leakage test when motor is hot to check.

It is definately oversize, as far as I know 84mm pistons= 40 thou oversize

😮 there some f :200sx_sailor: ckin clever people on this forum :200sx_200sx: :200sx_offtopic: