Hello all:
I'm looking for some experienced opinions on what to do here.
My 3 liter was blowing smoke at redline in 4th and high speed in 5th. Too much not to noitce... So she was taken out and stripped. The crank is being inspected and polished, sleeves are being checked and if needed, bored out a tad. I'm okay with the boring because I noticed a crack in one piston from the oil ring to the mid ring groove... so my plan is forged, custom pistons with total seal rings. 1985 GTV6 now has a rebuilt Verde box in it with the electronics coming from Mike in Australia (thanks Mike - great guy and VERY helpful) - this will allow the original speedo to work with the Verde gear ratios. Anyway, so what to do with the motor? I have 164 S cams and jet hot coated ANSA headers (car will be getting a custom exhaust when the motor goes back in)
Questions:
- should I bump the compression ratio up a little? How much?
- anything else while I'm in there?
I've been beating my head against the wall about a Gordon super charger but I'm a naturally aspirated kind of guy I think... 6 throttles sounds pretty cool to me.
Any ideas would be great. I'm thinking forged pistons because I want to install the Mega Squirt and new injectors and hopefully raise the rpms a little.
Thanks a lot,
Don P.
3.0 Liter rebuild
Thanks,
Don P.
Don P.
Howdy DP,
May I suggest 11:1 pistons? I have 10.5:1, but if I were living outside of California I would be using 11:1 - 11.5:1 for sure since I have the CB cams. With S-cams, 11:1 should be good. I guess you have 93 octane in MN?
Other than that, just new rod bolts (I didn't replace mine, I guess I should have), and ported intake runners. As far as balancing goes, if it's not going to constantly spin past 7000 rpms every other day, don't worry about balancing etc. Just make sure rods are in good condition.
May I suggest 11:1 pistons? I have 10.5:1, but if I were living outside of California I would be using 11:1 - 11.5:1 for sure since I have the CB cams. With S-cams, 11:1 should be good. I guess you have 93 octane in MN?
Other than that, just new rod bolts (I didn't replace mine, I guess I should have), and ported intake runners. As far as balancing goes, if it's not going to constantly spin past 7000 rpms every other day, don't worry about balancing etc. Just make sure rods are in good condition.
Engine
Hi Don,
Thanks for the compliments but cut it out. I'm going to get a swollen head !
I am surprised to see Zamani talking about such low octane fuel. Isn't 98 octane available in the US?
My limited knowledge about your problem Don is that you need to settle on the compression ratio to satisfy either a supercharging spec or one that is naturally aspirated. If the octane rating is only 93, running compression ratios of 11:1 or so is likely to give you detonation problems which is not what you want.
Essentially, what I am saying is that your compression ratio should be appropriate for your best octane fuel available that you are likely to be using all the time. Here in Oz, I use 98 octane on my 3 litre and it works great.
At this point I am hoping Greg Gordon might chime in and assist with a more technical approach regarding your CR objectives. If you want some real grunt however, I have to agree with Zamani, it is hard to go past a supercharger.
Cheers, Mike
Thanks for the compliments but cut it out. I'm going to get a swollen head !
I am surprised to see Zamani talking about such low octane fuel. Isn't 98 octane available in the US?
My limited knowledge about your problem Don is that you need to settle on the compression ratio to satisfy either a supercharging spec or one that is naturally aspirated. If the octane rating is only 93, running compression ratios of 11:1 or so is likely to give you detonation problems which is not what you want.
Essentially, what I am saying is that your compression ratio should be appropriate for your best octane fuel available that you are likely to be using all the time. Here in Oz, I use 98 octane on my 3 litre and it works great.
At this point I am hoping Greg Gordon might chime in and assist with a more technical approach regarding your CR objectives. If you want some real grunt however, I have to agree with Zamani, it is hard to go past a supercharger.
Cheers, Mike
Last edited by MD on Thu Oct 20, 2005 11:00 pm, edited 1 time in total.
Transaxle Alfas Haul More Arse
Engine
Zamani,
RON, MON, Peter & Sally. It's a whole lot clearer now !!
Times like these, I miss those lunatics, Barry and Jim Greek don't you?
RON, MON, Peter & Sally. It's a whole lot clearer now !!
Times like these, I miss those lunatics, Barry and Jim Greek don't you?
Transaxle Alfas Haul More Arse
Hmmmm...
Thanks guys... that helps a little bit.
As I told Greg Gordon, the costs are nearly the same for super charging and just pumping-up the CR and making the motor faster naturally.... Where would one get with porting, port matching, intake work, no AFM and a programable ECU, headers, 'Gordon' injectors and higher CR ratio? I THINK I'd be happy with ~50 hp gain but have no clue if this would get me there.
Unfortunately, I need to make up my mind before ordering pistons... Oh yeah, any recommendations on custom forged pistons? Venolia?
Nice talking to you guys again! It's been a while.
As I told Greg Gordon, the costs are nearly the same for super charging and just pumping-up the CR and making the motor faster naturally.... Where would one get with porting, port matching, intake work, no AFM and a programable ECU, headers, 'Gordon' injectors and higher CR ratio? I THINK I'd be happy with ~50 hp gain but have no clue if this would get me there.
Unfortunately, I need to make up my mind before ordering pistons... Oh yeah, any recommendations on custom forged pistons? Venolia?
Nice talking to you guys again! It's been a while.
Thanks,
Don P.
Don P.
oh yeah...
Zamani,
Yes, we've got 92 - 93 octane here. I usually use this in the everyday cars (which unfortunately are Volvos now... mistake!) So 11:1 eh? That sounds good...
Yes, we've got 92 - 93 octane here. I usually use this in the everyday cars (which unfortunately are Volvos now... mistake!) So 11:1 eh? That sounds good...
Thanks,
Don P.
Don P.
Progress?
I was told it needs to be bored "20 over".
when one buys a "rebuilt motor" one takes chances.... live and learn.
Zamani, the machine shop was not to hot on the 11:1 idea.... could you send me some more info on your ideas?
don@dpapa.com
Thanks,
Don P.
when one buys a "rebuilt motor" one takes chances.... live and learn.
Zamani, the machine shop was not to hot on the 11:1 idea.... could you send me some more info on your ideas?
don@dpapa.com
Thanks,
Don P.
Thanks,
Don P.
Don P.
Okay.....
Now the shop doing some work for me said they think I should pop for a new complete set of liners and pistons. Originally they were going to bore it 20 over and buy new, custom forged pistons...
I will supliment the wrist pins and rings with total seal and light weight pins. IAP will not break-up the set. So..... how much is a 3.2 conversion? 3.5?
Anyway, lot's to do. The shop and I (against Alfa Bible rules) are going to do some porting, lower end lightening and balancing, rod work, etc. and I'll post what I come up with.
Just want to do it right and gain some HP.
Ciao,
Don
Now the shop doing some work for me said they think I should pop for a new complete set of liners and pistons. Originally they were going to bore it 20 over and buy new, custom forged pistons...
I will supliment the wrist pins and rings with total seal and light weight pins. IAP will not break-up the set. So..... how much is a 3.2 conversion? 3.5?
Anyway, lot's to do. The shop and I (against Alfa Bible rules) are going to do some porting, lower end lightening and balancing, rod work, etc. and I'll post what I come up with.
Just want to do it right and gain some HP.
Ciao,
Don
Thanks,
Don P.
Don P.
DP,
Have you priced what your project will cost you against a stock 24V? Stock you're looking at 230 bhp.
Anyway for bigbore stuff, maybe you could ask Barry for the GTA crank? Or you can ask APE if they have used liners which are good. Or you know what, get a used 3.0L for $800 and part it out.
Why doesn't the shop want to rebore the liners anyway. Stock pistons are much heavier than forged ones.
Have you priced what your project will cost you against a stock 24V? Stock you're looking at 230 bhp.
Anyway for bigbore stuff, maybe you could ask Barry for the GTA crank? Or you can ask APE if they have used liners which are good. Or you know what, get a used 3.0L for $800 and part it out.
Why doesn't the shop want to rebore the liners anyway. Stock pistons are much heavier than forged ones.
The guy that is checking the block has been doing some research on it and said most people don't recommend boring the liners - I do not know his sources. I have not priced out a 24V but the thought of a blue printed 12v with around (hopefully) 220-230 hp sounds better to me. I bought this motor as "rebuilt" when I found it on gtv6.org classifieds - but it's more of a "new bearing" motor and thats about it. I'd rather know for a fact the motor is rebuilt and not take the gamble again.
This same guy told me the Borgo AE pistons are cast in a way that they're similar to forged pistons.....??? Force cast or something like that? not really sure. My hope was/is to buy forged pistons for the motor and tweak, tweak, tweak as I go.
What are the advantages of a GTA crank? It has a different front pulley and throw?
This same guy told me the Borgo AE pistons are cast in a way that they're similar to forged pistons.....??? Force cast or something like that? not really sure. My hope was/is to buy forged pistons for the motor and tweak, tweak, tweak as I go.
What are the advantages of a GTA crank? It has a different front pulley and throw?
Thanks,
Don P.
Don P.