Supercharging questions

Repiv · 09-28-2009, 04:01 PM

I'm working on swapping my rebuilt 4age into a supercharged car. I bought the car from the master tech at a toyota store and he got most of the stuff free so he doesn't remember exactly what he used. He told me this motor was built with "TRD forged pistons" OR "Silver something pistons" and had all kinds of bells and whistles done to it. I don't know the compression ratio on it but I do know I could run 87 gas with no problem/pinging/ect before it got wrecked. It's a 87 7 rib block with ~25k on it and the man who built it called it as close to as perfect of a motor you can build.

Anything I should be concerned about? Should I run a thicker headgasket to be safe? Another problem I've thought about is this supercharged car came with just the 10lb HKS pulley (blue)

Just looking for some advice before I start putting this motor together.

Jackstand Queen · 09-29-2009, 10:49 AM

This is a first for Mr2 history. A person swaps a naturally aspirated motor into a Super Charged model car.

You sir, are an automotive Frankenstein! Villagers armed with torches and pitchforks will arrive at your doorstep within the hour! Joking.

But seriously, there will be some significant wiring, and electronic device changes that would be necessary to stick an N. A. motor into an SC model car. And . . . . its virgin territory . . .. there are no how to's, no handy tutorials. It would take a seasoned master mechanic to work out all the problems involved.

mr2tim · 09-29-2009, 11:20 AM

Ditto w JQ wth?

I got the feeling we are going to be hearing a lot from you shortly.?

When your ready to sell that old HKS pulley pls keep me in mind for cash trade or barter for any NA parts you may ever need. (mr2tim)

Gonna be a big learning curve on what has been done to this car, tread softly.

It appears that a OEM headgasket is a reliable choice for longevity, contact our sponsor's rep from Lithia Toyota for just and fair quote.

We're assuming your a competant mechanic?

So what's your next question(s), (this is going to an interesting exchange I'm sure?)

Repiv · 09-29-2009, 11:38 AM

I'm not sticking a N/A motor in a sc car. I'm supercharging the n/a and sticking it in a supercharged car. Basicly a sc swap without having to worry about wiring.

The whole blown sc motor came with the car.

Jackstand Queen · 09-29-2009, 01:48 PM

An N.A. cylinder head's bolt patterns will not allow an SC intake and exhaust manifold to fit. So basically you need an SC head on your NA block.

The N.A.'s block internals could be beefed up to SC standards. The key and critical component would be lower compression (SC) pistons. Another approach to reduce compression ratio would be to fit in a custom thick headgasket. However, that would change the deck height, which would require adjustable cam gears to allow the change in deck height to work.

Silvertop pistons and rods are lighter versions of ordinary N.A. pistons and rods. Neither would last long in a supercharged regime.

I was glad to read that your post was not well worded, and that in fact you weren't thinking about doing the unthinkable. Putting an NA engine into an SC car. I'll send out a recall order to the outraged, torch carrying villagers immediately.

Best of Luck

IDon'tKnow · 09-29-2009, 02:01 PM

Does it bother you, the fact that the same person who is telling you "it has all of the bells and whistles", and that "it's as close to a perfect motor as you can build" is the same person who can't remember what pistons are in there?

If I were buying an untested newly built motor, that would make me VERY nervous. I would expect the person to be able to tell me not just what brand or type of piston, but also what size, what rings were used, what con-rods were used, if factory; was the hardware upgraded, aftermarket or OEM bearings?.... this list goes on and on.

If he can't tell you what pistons are in there, what makes you think he knows what he is talking about when he says it has bells, whistles, and is nigh perfect?

Just my two cents.

Repiv · 09-29-2009, 03:17 PM

He is a respectable mechanic and runs the biggest toyota shop in Memphis. He built the motor with a friend of his and his friend got all the parts for free. Basicly he was just building the motor and didn't care from what I understand. I drove the car for 6 months and it is definitely not "untested"

He seemed pretty sure that they were TRD forged pistons. They definitely aren't high comp. pistons.

IDon'tKnow · 09-29-2009, 04:01 PM

Interesting. I didn't notice that the motor wasn't fresh out of the shop.

I don't know if this is really a good idea, but here goes:
Instead of pulling the engine apart to measure the piston dish and the chamber volume on the head, you could get yourself a powerful flashlight, syringe with clear volume markings, 100ml's or so of gasoline, and some food coloring.

Put cylinder #1 at TDC, pull the spark plug, and 10ml's at a time fill the combustion chamber with the mixture of gasoline and food coloring. The food coloring would just make it easier to see the liquid, well... might.... may not be neccessary. Once your 10ml steps bring the fluid up above the plug threading on the head you should be able to carefully suction the excess out and note the volume to tally up your chamber volume.

Once you know the chamber volume you can add that to the cylinder volume (1587cc if you have an 81mm bore, 1607cc if you're .5mm over stock, which I assume you are since your motor is built) to get the total volume. Then just take that number and divide it by the chamber volume to determine what your compression ratio is.

Of course this will only work if you have a good ring seal to the cylinder wall - I assume you will since the motor is practically new. Keep in mind this is purely my theorizing and I haven't personally tried this method.

Repiv · 10-01-2009, 09:27 AM

Quote:

Originally Posted by Jackstand Queen

An N.A. cylinder head's bolt patterns will not allow an SC intake and exhaust manifold to fit. So basically you need an SC head on your NA block.

I'm not finding this to be true. My N.A. exhaust and N.A intake went on the SC head just fine. I can't test the other way around since my sc intake is getting a broke off bolt removed. I have to change the studs for the intake but that is no big deal.

toyotaspeed90 · 10-01-2009, 03:17 PM

has to be like for like.... if the s/c engine is a stock mk1, then it has a bigport head.... all bigport heads have the same intake and exhaust port pattern & bolt pattern.... you may need to use the shorter studs on the intake manifold, as the gze didn't use t-vis and used shorter studs than the n/a manifolds that did.

in any event.... if you are putting a HG in then take photos of the pistons... we can tell you what they are.

either way, there is more than just the piston's dome shape that differs in the gze motors.... the engine will NOT be as reliable as a gze if it has ANY n/a 4age pistons.

te51levin · 10-01-2009, 11:26 PM

Quote:

Originally Posted by Repiv

I'm not finding this to be true. My N.A. exhaust and N.A intake went on the SC head just fine. I can't test the other way around since my sc intake is getting a broke off bolt removed. I have to change the studs for the intake but that is no big deal.

There is no difference between NA and SC cylinder heads. Manifold bolt patterns are the same, as is everything else.

Jackstand Queen, you've been spending too much time drinking mead with the torch-wielding villagers

Repiv · 10-03-2009, 05:05 PM

Yeah I finally got my engine on an engine stand so i'll be taking off the heads soon.

The engine has fully forged internals so hopefully it can handle the boost as long as I get the cr down.

Jackstand Queen · 10-03-2009, 06:40 PM

My bad, I think I got confused about 20v and Jspec small port heads differing from N.A. USDM heads.

I don't envy Repiv needing to do volumetric calculations that factor in a given headgasket's thickness and how that changes CR and displacement. Oh, my head hurts just thinking about it. But with a little bit of googling and studying up, it can be done.

Do.

The.

Math.

I found a pair of Fidanza adjustable cam pulleys last month for under 2 hundred shipped. So, its not too bad as parts go.

IDon'tKnow · 10-03-2009, 11:55 PM

So let me get this straight.... Your NA motor has forged TRD pistons but they aren't high comp?

Repiv · 10-04-2009, 01:41 AM

I can't imagine them being any higher than stock since I could run trash gas to no ill effect. What CR should I aim for safely? Also what kind of boost would I be getting with the stock 4age pulley if I decide I don't want to run the HKS 10lb pulley.

The motor already has adjustable cam gears. The SC car also came with HKS 264 degree cams that I'm debating putting in.

IDon'tKnow · 10-04-2009, 11:47 AM

Since you're pulling the head anyway I think it's sound advice to reccomend you measure the bores and CC the deck and chamber. All you need to do that is water, food coloring, alcohol, a graduated cylinder, and an acrylic plate with a small hole in it.

Once you know the chamber volume you'll be ready to calculate your CR. For every .2mm of head gasket you use you'll be adding .398cc's per cylinder if you're still at 81mm.

Repiv · 10-05-2009, 10:57 AM

My oversized pulley is 180mm... Definitely not putting that in. If anyone is interested in it send me a pm and maybe we can work something out for a stock unit + cash.

Repiv · 10-08-2009, 02:46 PM

Head is off. Here's a picture of the piston. Definitely glad I took the head off.

IDon'tKnow · 10-08-2009, 03:28 PM

That definitely looks like a high comp piston to me.

Repiv · 10-08-2009, 03:42 PM

Quote:

Originally Posted by IDon'tKnow

That definitely looks like a high comp piston to me.

Agree 100%. Now I have to figure out how low I can get the cr. I've been thinking of just running the stock 4age pulley since it is smaller than the 4agze one and will give me a little lower boost. Anyone know how many lbs the 4age pulley will give?

09-28-2009, 04:01 PM	#1 (permalink)
Repiv No Skills Join Date: Jan 2009 Posts: 16 Thanks: 0 Thanked 0 Times in 0 Posts iTrader Rating: (0/0% )	Supercharging questions I'm working on swapping my rebuilt 4age into a supercharged car. I bought the car from the master tech at a toyota store and he got most of the stuff free so he doesn't remember exactly what he used. He told me this motor was built with "TRD forged pistons" OR "Silver something pistons" and had all kinds of bells and whistles done to it. I don't know the compression ratio on it but I do know I could run 87 gas with no problem/pinging/ect before it got wrecked. It's a 87 7 rib block with ~25k on it and the man who built it called it as close to as perfect of a motor you can build. Anything I should be concerned about? Should I run a thicker headgasket to be safe? Another problem I've thought about is this supercharged car came with just the 10lb HKS pulley (blue) Just looking for some advice before I start putting this motor together.

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09-29-2009, 10:49 AM	#2 (permalink)
Jackstand Queen Cage Fighter Join Date: May 2008 Posts: 677 Thanks: 52 Thanked 56 Times in 53 Posts iTrader Rating: (1/100% )	This is a first for Mr2 history. A person swaps a naturally aspirated motor into a Super Charged model car. You sir, are an automotive Frankenstein! Villagers armed with torches and pitchforks will arrive at your doorstep within the hour! Joking. But seriously, there will be some significant wiring, and electronic device changes that would be necessary to stick an N. A. motor into an SC model car. And . . . . its virgin territory . . .. there are no how to's, no handy tutorials. It would take a seasoned master mechanic to work out all the problems involved.

09-29-2009, 11:20 AM	#3 (permalink)
mr2tim SUPERcharZed ToyZ RacZer Join Date: Mar 2008 Location: South Florida Posts: 690 Thanks: 2 Thanked 41 Times in 38 Posts My Google Map iTrader Rating: (2/100% )	Ditto w JQ wth? I got the feeling we are going to be hearing a lot from you shortly.? When your ready to sell that old HKS pulley pls keep me in mind for cash trade or barter for any NA parts you may ever need. (mr2tim) Gonna be a big learning curve on what has been done to this car, tread softly. It appears that a OEM headgasket is a reliable choice for longevity, contact our sponsor's rep from Lithia Toyota for just and fair quote. We're assuming your a competant mechanic? So what's your next question(s), (this is going to an interesting exchange I'm sure?)

09-29-2009, 11:38 AM	#4 (permalink)
Repiv No Skills Join Date: Jan 2009 Posts: 16 Thanks: 0 Thanked 0 Times in 0 Posts iTrader Rating: (0/0% )	I'm not sticking a N/A motor in a sc car. I'm supercharging the n/a and sticking it in a supercharged car. Basicly a sc swap without having to worry about wiring. The whole blown sc motor came with the car.

09-29-2009, 01:48 PM	#5 (permalink)
Jackstand Queen Cage Fighter Join Date: May 2008 Posts: 677 Thanks: 52 Thanked 56 Times in 53 Posts iTrader Rating: (1/100% )	An N.A. cylinder head's bolt patterns will not allow an SC intake and exhaust manifold to fit. So basically you need an SC head on your NA block. The N.A.'s block internals could be beefed up to SC standards. The key and critical component would be lower compression (SC) pistons. Another approach to reduce compression ratio would be to fit in a custom thick headgasket. However, that would change the deck height, which would require adjustable cam gears to allow the change in deck height to work. Silvertop pistons and rods are lighter versions of ordinary N.A. pistons and rods. Neither would last long in a supercharged regime. I was glad to read that your post was not well worded, and that in fact you weren't thinking about doing the unthinkable. Putting an NA engine into an SC car. I'll send out a recall order to the outraged, torch carrying villagers immediately. Best of Luck

09-29-2009, 02:01 PM	#6 (permalink)
IDon'tKnow but I can find out. Join Date: Sep 2009 Location: Huntsville, AL Posts: 137 Thanks: 4 Thanked 2 Times in 2 Posts iTrader Rating: (1/100% )	Does it bother you, the fact that the same person who is telling you "it has all of the bells and whistles", and that "it's as close to a perfect motor as you can build" is the same person who can't remember what pistons are in there? If I were buying an untested newly built motor, that would make me VERY nervous. I would expect the person to be able to tell me not just what brand or type of piston, but also what size, what rings were used, what con-rods were used, if factory; was the hardware upgraded, aftermarket or OEM bearings?.... this list goes on and on. If he can't tell you what pistons are in there, what makes you think he knows what he is talking about when he says it has bells, whistles, and is nigh perfect? Just my two cents.

09-29-2009, 03:17 PM	#7 (permalink)
Repiv No Skills Join Date: Jan 2009 Posts: 16 Thanks: 0 Thanked 0 Times in 0 Posts iTrader Rating: (0/0% )	He is a respectable mechanic and runs the biggest toyota shop in Memphis. He built the motor with a friend of his and his friend got all the parts for free. Basicly he was just building the motor and didn't care from what I understand. I drove the car for 6 months and it is definitely not "untested" He seemed pretty sure that they were TRD forged pistons. They definitely aren't high comp. pistons.

09-29-2009, 04:01 PM	#8 (permalink)
IDon'tKnow but I can find out. Join Date: Sep 2009 Location: Huntsville, AL Posts: 137 Thanks: 4 Thanked 2 Times in 2 Posts iTrader Rating: (1/100% )	Interesting. I didn't notice that the motor wasn't fresh out of the shop. I don't know if this is really a good idea, but here goes: Instead of pulling the engine apart to measure the piston dish and the chamber volume on the head, you could get yourself a powerful flashlight, syringe with clear volume markings, 100ml's or so of gasoline, and some food coloring. Put cylinder #1 at TDC, pull the spark plug, and 10ml's at a time fill the combustion chamber with the mixture of gasoline and food coloring. The food coloring would just make it easier to see the liquid, well... might.... may not be neccessary. Once your 10ml steps bring the fluid up above the plug threading on the head you should be able to carefully suction the excess out and note the volume to tally up your chamber volume. Once you know the chamber volume you can add that to the cylinder volume (1587cc if you have an 81mm bore, 1607cc if you're .5mm over stock, which I assume you are since your motor is built) to get the total volume. Then just take that number and divide it by the chamber volume to determine what your compression ratio is. Of course this will only work if you have a good ring seal to the cylinder wall - I assume you will since the motor is practically new. Keep in mind this is purely my theorizing and I haven't personally tried this method.

10-01-2009, 03:17 PM	#10 (permalink)
toyotaspeed90 No Skills Join Date: Jun 2006 Location: Bellingham, WA Posts: 435 Thanks: 0 Thanked 32 Times in 32 Posts My Google Map iTrader Rating: (0/0% )	has to be like for like.... if the s/c engine is a stock mk1, then it has a bigport head.... all bigport heads have the same intake and exhaust port pattern & bolt pattern.... you may need to use the shorter studs on the intake manifold, as the gze didn't use t-vis and used shorter studs than the n/a manifolds that did. in any event.... if you are putting a HG in then take photos of the pistons... we can tell you what they are. either way, there is more than just the piston's dome shape that differs in the gze motors.... the engine will NOT be as reliable as a gze if it has ANY n/a 4age pistons.

10-03-2009, 05:05 PM	#12 (permalink)
Repiv No Skills Join Date: Jan 2009 Posts: 16 Thanks: 0 Thanked 0 Times in 0 Posts iTrader Rating: (0/0% )	Yeah I finally got my engine on an engine stand so i'll be taking off the heads soon. The engine has fully forged internals so hopefully it can handle the boost as long as I get the cr down.

10-03-2009, 06:40 PM	#13 (permalink)
Jackstand Queen Cage Fighter Join Date: May 2008 Posts: 677 Thanks: 52 Thanked 56 Times in 53 Posts iTrader Rating: (1/100% )	My bad, I think I got confused about 20v and Jspec small port heads differing from N.A. USDM heads. I don't envy Repiv needing to do volumetric calculations that factor in a given headgasket's thickness and how that changes CR and displacement. Oh, my head hurts just thinking about it. But with a little bit of googling and studying up, it can be done. Do. The. Math. I found a pair of Fidanza adjustable cam pulleys last month for under 2 hundred shipped. So, its not too bad as parts go.

10-03-2009, 11:55 PM	#14 (permalink)
IDon'tKnow but I can find out. Join Date: Sep 2009 Location: Huntsville, AL Posts: 137 Thanks: 4 Thanked 2 Times in 2 Posts iTrader Rating: (1/100% )	So let me get this straight.... Your NA motor has forged TRD pistons but they aren't high comp?

10-04-2009, 01:41 AM	#15 (permalink)
Repiv No Skills Join Date: Jan 2009 Posts: 16 Thanks: 0 Thanked 0 Times in 0 Posts iTrader Rating: (0/0% )	I can't imagine them being any higher than stock since I could run trash gas to no ill effect. What CR should I aim for safely? Also what kind of boost would I be getting with the stock 4age pulley if I decide I don't want to run the HKS 10lb pulley. The motor already has adjustable cam gears. The SC car also came with HKS 264 degree cams that I'm debating putting in.

10-04-2009, 11:47 AM	#16 (permalink)
IDon'tKnow but I can find out. Join Date: Sep 2009 Location: Huntsville, AL Posts: 137 Thanks: 4 Thanked 2 Times in 2 Posts iTrader Rating: (1/100% )	Since you're pulling the head anyway I think it's sound advice to reccomend you measure the bores and CC the deck and chamber. All you need to do that is water, food coloring, alcohol, a graduated cylinder, and an acrylic plate with a small hole in it. Once you know the chamber volume you'll be ready to calculate your CR. For every .2mm of head gasket you use you'll be adding .398cc's per cylinder if you're still at 81mm.

10-05-2009, 10:57 AM	#17 (permalink)
Repiv No Skills Join Date: Jan 2009 Posts: 16 Thanks: 0 Thanked 0 Times in 0 Posts iTrader Rating: (0/0% )	My oversized pulley is 180mm... Definitely not putting that in. If anyone is interested in it send me a pm and maybe we can work something out for a stock unit + cash.

10-08-2009, 02:46 PM	#18 (permalink)
Repiv No Skills Join Date: Jan 2009 Posts: 16 Thanks: 0 Thanked 0 Times in 0 Posts iTrader Rating: (0/0% )	Head is off. Here's a picture of the piston. Definitely glad I took the head off.

10-08-2009, 03:28 PM	#19 (permalink)
IDon'tKnow but I can find out. Join Date: Sep 2009 Location: Huntsville, AL Posts: 137 Thanks: 4 Thanked 2 Times in 2 Posts iTrader Rating: (1/100% )	That definitely looks like a high comp piston to me.