3.3 to 3.5 upgrade

[vmisquez]

I need some guidance from the board.

Since I have the motor apart its time for upgrade and I want to build the motor is steps so I do not back myself in a corner.

Here's my stage one plan. Please let me know if you see any problems with this build sheet

1. JE 3.5L 7.5 CR pistons/barrels
2. AI CIS Fuel Head mod
3. Brian's Adj. WUR & RPM circuit
4. Fab Speed Muffler
5. 964 Cams
6. Port heads to 36 mm
7. Stock waste gate. turbo and IC.
8. Racing valve springs
9. ARP rod bolts and head studs

I'll update 7. to K27 HFS; larger IC and 1 bar spring when I need my next boost fix unless the consense advises otherwise.

Thanks for your time.

V.

[turbobrat930]

you have PM

[WydRyd]

Looks like a sound build sheet indeed... how about a nice 993 crank for added torque & displacement

[89turbocabmike]

I'm assuming your going to get to 3.5 with P/C, since I don't see any mention of a crank?

Many well respected builders, including Steve@Rennsport would recommend against 3.5 from slip-ins. Perhaps Charles' Nickies might be a better way, though I have yet to hear any first hand use of them. Maybe try 98mm and a stroker crank(964/993).

[930gt-40r]

Diddo on what 89turbocabmike says, 3.5s (100mm?) may be too much. you can almost get 3.5 out of 98mm cyls and the 964/993 crank. I recomend the 964 crank as it has bigger rod journals and is considered the strongest street crank we got. I wouldnt bore the case for larger cylinders because I have never seen or heard of one that didnt leak oil from the base gasket. A good set of rods are in order as well (Carrilo, Pauter, etc...) But it also seems like a lot of work just to be putting cis back on the motor. Would you consider EFI?

[vmisquez]

Thank you all for your insight. I was not aware of oil leak problems with boring out the case. I asked a reputable Porsche machine shop located in Santa Ana about boring out the case and they said the case could be bored out to 3.8L without any problems. I guess I did not ask the right question about cylinder sealing issues.

I do not like oil leaks and IMHO oil leaks are a sign of a poor rebuild.

I may just keep my stop P/C since they have about 2K on new rings and
I have excellent leak down

Investing in a stronger stroked crank with upgraded rods now makes more sense. I have a few more questions if you don't mind

1. What hardware do I need to get the 964/993 stroked crank to match the internals of my case?

2. Do I need to perform any special work on my existing stock 3.3L P/C so they will still seal with this new longer stroke?


I'm also going to have the heads twin-plugged for future upgrades when I finally do EFI.

Thanks for you help.

V.

[vmisquez]

Which crank is best to build a stroker 964 or 993? Are these the same crank? I may have found one of each locally I'm still flowing up on leads. Should I purchade the crank pulley as well?

Thanks.

V.

[turbobrat930]

hey, did you check you private messages??? I have just completed everything you are setting out to do. I used my original 3.3L crank, and had it stroked. I gained 2mm more stroke than what the 964 crank will give you. With 98mm P&C's I now have just under a 3.6L.... I have been told that the 3.3L crank is better, as it is fully counterweighted, and the 964 crank is not completely counterweighted. I had my rod journals offset ground and used Pauter rods... The crank now has chevy 2" rod journals. I now have an infinate supply fo rod bearing choices, to include nascar stuff. Check you PM's aand give me a call..... Bradf

[vmisquez]

Brad, I was told that stoking the 3.3L crank is too risky since it is a complicated process. I had originally set out to have the crank stroked by Ollie's in Santa Ana. How many miles do you have on the stroked crank?

V.

[Candelaria]

Originally posted by 930gt-40r
Diddo on what 89turbocabmike says, 3.5s (100mm?) may be too much. you can almost get 3.5 out of 98mm cyls and the 964/993 crank. I recomend the 964 crank as it has bigger rod journals and is considered the strongest street crank we got. I wouldnt bore the case for larger cylinders because I have never seen or heard of one that didnt leak oil from the base gasket. A good set of rods are in order as well (Carrilo, Pauter, etc...) But it also seems like a lot of work just to be putting cis back on the motor. Would you consider EFI?

Base of cylinders won't leak if you use the 3.8 RS seals, you got to cut a grove inside of the case spigots, and use the RS o-rings.
Candy.

[WydRyd]

If you do intend to go EFI and run serious boost, I'd recommend having the heads/liners flame-ringed to provide best sealing at big power levels.

If I was to do it all again, I'd flame-ring for sure. The C2T head gaskets seal very well for up to 1.4bar of boost, but anything higher than that is questionable. That's where flamed-rings takes over

[vmisquez]

Hello again,

I should have a good 964 crank with 40K mile soon so it looks like the engine will be stroked. Has anyone ever installed a 964 crank in their 930? I would appreciate any advice as I worried about offsetting the piston/valve clearance, piston/head clearance and compression ratio.

My current stock P/C's are currently being inspected and I may go for the larger barrels with the RS sealing rings (thanks Candy)
if they fail inspection.

I'm more interested in a reliable fun car and will not run more than .8 bar boost. (until I get the twin plugs setup and then up to 1.2)

My objective is to build up the long block with enough displacement
with twin-plugged heads to allow for future mods but will also provide a fun car with CIS and stock turbo/wastegate.

EFI is definately in the future but just can't budget all the goodies
now.

If I need new P/Cs then why not get the next larger size, prep the case (and use RS sealing rings) and use a 964 crank. I should be able to sell my stock crank since it's perfect and will come with an inspection check from Ollie's Automotive.


Thanks for your time.

V.
I'll keep you all posted on how this project progress.

[Facey]

it reallt does (IMO) make sense to go as large discplacement as possible.

it will make it a much funner car when off boost. 100mm+ P&C's with a 964 crank sounds like tones of fun with ~1 bar, twin plugs and efi.

even w/o boost it sounds fun!!!! (i drive a 3.5L and its a beast IMO).