My game plan ( :

[Pendulum]

So I just picked up my 1st 240, although I've been lusting after one since I was 13. Due to the huge drift craze they were too hard to come by until lately, so I'm migrating over from the Honda camp. I've got an S13 base model coupe, needs an engine/trans. I've decided to go KA-T for a few reasons.

Here's my plan:
Pick up a DOHC with around 100k and putt around with that for ~2 months, while I piece together everything to rebuild it.
Pull the engine, and rebuild it to OEM spec or as close as possible, adding only ARP head studs and a Cometic HG.

I plan on driving it this way for about 10k miles, then boosting it. My goal is high 200's, low 300's at the wheels. From the research I've done, a stock KA can handle that. My car supposedly has a Z32 fuel pump (per the seller. He said this flows near as much, maybe more than, the Walbro 255lph), and I've got an excellent tuner that's about 20 minutes from my house.

I haven't decided if I should purchase a kit, or piece it together myself but here's my list of stuff:

Piston set (OEM spec from a reputable brand)
Timing chain set (wtf is a timing chain? lol Hondas have belts!)
ARP head studs
Engine gasket set
Rod bearings
main bearings
H2O pump

Am I missing anything? I'll probably do the oil pump, too while I'm at it. Also, what're the chances my block will need machining? I've never built a bottom end before.

[Dousan_PG]

id slap on the turbo kit and tune till the engine blows
THEN rebuild it.

[demonspeed]

id slap on the turbo kit and tune till the engine blows
THEN rebuild it.

+1 on that idea lol! as for the turbo kit, if i were you i would just buy the parts individually...no sense on spending $1200+ when you can get the same thing (or almost the same) for at least 300-350 less

[Pendulum]

Yeah, I'm definitely going to build my own turbo system...
And I thought about boosting it right off the bat, but I don't want it blowing up and getting damaged. I'd hate to have to buy another block or something. The reference to buying a kit was in terms of the rebuild kit.

[jspaeth]

Here's my plan:
Pick up a DOHC with around 100k and putt around with that for ~2 months, while I piece together everything to rebuild it.
Pull the engine, and rebuild it to OEM spec or as close as possible, adding only ARP head studs and a Cometic HG

I haven't decided if I should purchase a kit, or piece it together myself but here's my list of stuff:

Piston set (OEM spec from a reputable brand)
Timing chain set (wtf is a timing chain? lol Hondas have belts!)
ARP head studs
Engine gasket set
Rod bearings
main bearings
H2O pump

Am I missing anything? I'll probably do the oil pump, too while I'm at it. Also, what're the chances my block will need machining? I've never built a bottom end before.


If you read around on here, most of the more experienced folks will tell you that Cometic is shit.......I would listen to their words of wisdom and get something better for an extra $100.

A timing chain is the same thing as a timing belt, but way better. It's made of metal obviously and that just makes ME feel more comfortable knowing that a piece of rubber with grooves in it is not what is turning my camshafts.

[R33E8]

If you read around on here, most of the more experienced folks will tell you that Cometic is shit.......I would listen to their words of wisdom and get something better for an extra $100.


Cometic is not shit.. Most people who have issues fail to surface the head AND block to the required smoothness which causes leaks..

But anyways, I would recommend using a Fel-Pro gasket.. It's cheaper and there are plenty of KA-Ts using Fel-Pros pushing over 500whp with no problems.. I have a KA-T using a Fel-Pro head gasket and running a gt35... I would rather my head gasket blow before something else..

[jspaeth]

Cometic is not shit.. Most people who have issues fail to surface the head AND block to the required smoothness which causes leaks..

But anyways, I would recommend using a Fel-Pro gasket.. It's cheaper and there are plenty of KA-Ts using Fel-Pros pushing over 500whp with no problems.. I have a KA-T using a Fel-Pro head gasket and running a gt35... I would rather my head gasket blow before something else..


Yeah they are shit....someone on some thread on here posted up X-Ray images of the different brands.

The good ones are beefy as hell in the ring around the cylinders.....the cometic looked barely any different there than in regions far from a passageway....

Anyway cosworth, apexi are really good man

[fcdrifter20]

Yeah they are shit....someone on some thread on here posted up X-Ray images of the different brands.

The good ones are beefy as hell in the ring around the cylinders.....the cometic looked barely any different there than in regions far from a passageway....

Anyway cosworth, apexi are really good man

I have to agree cosmetics are booboo..have had nothing but bad experiences with them. spend some extra cash and go with something bettr....

oh and i would also change rod studs, i usualy do that when i go with stock rods and boost a ka, just to be safe. oh and if ur gona go with a new timing set, i know they are a bit pricey, but please don't go and get one from Ebay....U WILL HAVE PROBLEMS LATER..please dont make that mistake like so many others do. and dont forget a tune and some bettr injectors

[Dousan_PG]

ive used a cometic for like 2 years or so maybe more when i rebuilt my engine. 9:1 ocmpression, big turbos decent boost 1.5 to 1 bar ranges and tracked only in hot temps (110F days)
and its totally fine.

it always comes down to install most of the time. most people/builders are retarded.

[jspaeth]

ive used a cometic for like 2 years or so maybe more when i rebuilt my engine. 9:1 ocmpression, big turbos decent boost 1.5 to 1 bar ranges and tracked only in hot temps (110F days)
and its totally fine.

it always comes down to install most of the time. most people/builders are retarded.


Ok that's the consensus, but what can you say for the difference in construction? Those X-ray images clearly show that the more expensive gaskets have reinforcement around the cylinders and oil/water passages

[R33E8]

Ok that's the consensus, but what can you say for the difference in construction? Those X-ray images clearly show that the more expensive gaskets have reinforcement around the cylinders and oil/water passages

I think those images were from a company promoting their own product...
Is this the thread you are talking about?

Why Buy The Cosworth Headgasket? - SR20 Community Forum - The Dash (http://www.sr20-forum.com/general-sr20/3269-why-buy-cosworth-headgasket.html)

From those pictures I think I would actually choose the Cometic head gasket. The pressure around the oil and water passages seem to be better than the others. The amount of force exerted around the cylinders should also be higher. Since the seal around the cylinder is thinner it should be creating a stronger seal than the head gaskets that distribute the force over a slightly larger area. The only problem I see with the Cometic gasket is the inner ring doesn't seam to go all the way around the cylinder. I'm not sure if that's a defect with the gasket or something else.

Also, Copper Spray isn't supposed to be used on Cometic head gaskets. The spray makes the Viton coating swell and do funny things.. I know plenty of people probably use the spray anyways and will claim it helps but this is just what I heard Cometic say.

Here is a post from my local forum if you want to fully understand why copper spray shouldn't be used:

My contention has always been: You want to have a MHG seal correctly? The RA spec (or smoother) for the specific MHG must be met for both the block and head, the machine work must be precisely flat for both the block and head, and the proper torque spec for the fastener used must be applied in the TRSM sequence. Attention to detail on these is what ensures a proper seal.

I have also said (several times) that the use of a spray sealer (such as Permatex Copper, Brake Quiet, etc.) can damage the fluoroelastomer coating the MHG manufacturers use on their product. However, I've never really backed it up other than a single line in the first article. I decided to research this...first a little background:

Viton (by DuPont) is the most common fluoroelastomer coating; it is used to initiate the initial cold seal on a MHG. It is applied in a very thin layer and is an inert, tough, heat resistant coating. It is one of the more expensive fluoroelastomers out there, and actually is manufactured in four families…the one we are interested in is for automotive applications. It is highly resistant to oil, gasoline, nitro methane, and alcohol. However there are certain chemicals that will affect it. From a tech article on Viton:

“In general, low molecular weight ketones and esters will swell a vulcanizate of Viton and, in fact, ketones such as methyl ethyl ketones are used as solvents for uncured Viton®. Esters such as ethyl acetate are also used as solvents for Viton. The more polar a material the more likely it will swell Viton. Much work is being done in the area of solubility parameters to characterize the swelling behavior of various fluids by comparison of dispersion, hydrogen bonding and dipole parameters to the corresponding parameters of the elastomer.

Amines affect Viton® differently from the ketones and esters. Generally, amines will react with the polymer backbone and result in embrittlement of the vulcanizate. The elongation will drop off significantly and hardness will increase. Amines are just one kind of base. In general, strong bases such as sodium hydroxide at relatively high concentrations will degrade Viton®. In summary, a basic understanding of chemistry is helpful in judging an elastomer's resistance to swelling or degradation.”

Now...the question is are any of these chemicals in a spray sealer? If you read the back of a can of Permatex Copper Spray-a-Gasket, it contains methylene chloride (a simple chlorohydrocarbon), acetone (a ketone), and ethyl acetate (an ester). Take another look at the tech article quote above…since acetone is a ketone, it will attack Viton. I have personally used acetone to clean the old Viton off in order to re-use a MHG. Ethyl acetate is specifically mentioned above as a solvent for Viton...I do believe we have the culprit Dr. Watson! Acetone and ethyl acetate can cause Viton to swell, making its ability to seal very questionable.

The most common counter I hear for using a spray sealer is “I’ve always used it and never had a problem”. That’s fine…use it if you want, but realize that you are applying chemicals that can dissolve the fluoroelastomer coating designed and engineered for the MHG you are using.

I also hear “Cometic says it’s not required, not that it’s not recommended”. Well, I called Cometic and spoke to one of their engineers…his response was “our gaskets do not need additional sealer…we do not recommend using it.” Using a little common sense and knowing how the chemicals in a spray sealer affect Viton, it’s no wonder they do not recommend it. BTW…I couldn’t get HKS to talk to me

Everyone here is free to make their choice. After reading up on the chemistry, I’m not going to use a spray sealer regardless who says it’s ok. Chemistry does not lie...this is not based on hearsay. I’m pretty positive the engineers know what they are doing on this one

[Pendulum]

I was planning on some 370cc injectors, but didn't list them because that's not part of the rebuild, that's part of the boosting which won't be happening until at LEAST Spring 2010. Maybe fall of 2010.

As far as the HG, I had overlooked the Cosworth because I thought it was some random company using the name. Now that I know it's THE Cosworth, I'm definitely looking into their head gaskets.

Thanks for the info guys. I'll be starting a build thread once I get an engine.

[R33E8]

I read that Cosworth isn't that same as it used to be.. I'll post a link to what I read once I find it.. Basically if I remember correctly, a few rich guys bought it for their race team, then some other rich guy bought it for their team, some more stuff happened, and now it is what it is today..

[jspaeth]

Is this the thread you are talking about?

Why Buy The Cosworth Headgasket? - SR20 Community Forum - The Dash (http://www.sr20-forum.com/general-sr20/3269-why-buy-cosworth-headgasket.html)



Yes that's the one.....it clearly shows that the Cosworth is way better. Maybe I just read it wrong.

[fcdrifter20]

I think those images were from a company promoting their own product...
Is this the thread you are talking about?

Why Buy The Cosworth Headgasket? - SR20 Community Forum - The Dash (http://www.sr20-forum.com/general-sr20/3269-why-buy-cosworth-headgasket.html)

From those pictures I think I would actually choose the Cometic head gasket. The pressure around the oil and water passages seem to be better than the others. The amount of force exerted around the cylinders should also be higher. Since the seal around the cylinder is thinner it should be creating a stronger seal than the head gaskets that distribute the force over a slightly larger area. The only problem I see with the Cometic gasket is the inner ring doesn't seam to go all the way around the cylinder. I'm not sure if that's a defect with the gasket or something else.

Also, Copper Spray isn't supposed to be used on Cometic head gaskets. The spray makes the Viton coating swell and do funny things.. I know plenty of people probably use the spray anyways and will claim it helps but this is just what I heard Cometic say.

Here is a post from my local forum if you want to fully understand why copper spray shouldn't be used:


i think you read it incorrectly. It clearly states that the Cosworth is better.

[s15specR]

I was told by a few shops that cometic makes cosworth, even a few sponsors on here mentioned that. Best guess is they may be made to Cosworth's specs by cometic ??

[R33E8]

Yes that's the one.....it clearly shows that the Cosworth is way better. Maybe I just read it wrong.

i think you read it incorrectly. It clearly states that the Cosworth is better.

I know it states that the Cosworth is better, but I'm ignoring what he says and looking directly at the picture. Why would an engineer at Cosworth put down their own product? I would like a to see a third party do this testing, not someone praising their own product..