8v head (2.0) 16v bottom end?

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turbo_cabby
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8v head (2.0) 16v bottom end?

Post by turbo_cabby »

i was sent here by SoCal_Cabby from the vortex...but I was told by a performance shop in jersey (hodis performance) that i should do an 8v head with a 16 v bottom end (i beleive) and i can basically boost the sh!t out of it....can anyone here give me some more information.
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Post by PDX Cabby »

as i mentioned here viewtopic.php?t=460

8v bottom ends (1.8 & 2.0) combined with a 16v head (1.8 or 2.0) make a great low compresstion motor primed and ready for boost

the combination will give you approx 7.8:1 compression. With the right intercooling that means you can get A LOT of boost

however
there is one thing to look out for: Valve Clearance.
the combination gives you an extremely thin valve/piston clearance. Less than a full millimeter if i remember correctly. This can be easily resolved by having a machineshop knotch the 8v pistons to give you added clearance. This will also slightly lower your compression just a hair more.
85 Cab - 1.9L 8v, g-grind, euro dual downs to TT race w/ Borla, VWMS fuel dizzy, 2H tranny with 5th gear swap, TT short shift, FK 60/40, 15" BBS RA, rear disks... begging for boost...
turbo_cabby
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Post by turbo_cabby »

PDX Cabby wrote:as i mentioned here viewtopic.php?t=460

8v bottom ends (1.8 & 2.0) combined with a 16v head (1.8 or 2.0) make a great low compresstion motor primed and ready for boost

the combination will give you approx 7.8:1 compression. With the right intercooling that means you can get A LOT of boost

however
there is one thing to look out for: Valve Clearance.
the combination gives you an extremely thin valve/piston clearance. Less than a full millimeter if i remember correctly. This can be easily resolved by having a machineshop knotch the 8v pistons to give you added clearance. This will also slightly lower your compression just a hair more.
thanks for the help, and sorry for the inconvience i guess i shoulda hve done a search first...
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Post by PDX Cabby »

nah, search wouldn't have done anything... looks like ya snuck in a post without logging in... no biggie
85 Cab - 1.9L 8v, g-grind, euro dual downs to TT race w/ Borla, VWMS fuel dizzy, 2H tranny with 5th gear swap, TT short shift, FK 60/40, 15" BBS RA, rear disks... begging for boost...
turbo_cabby
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Post by turbo_cabby »

PDX Cabby wrote:nah, search wouldn't have done anything... looks like ya snuck in a post without logging in... no biggie
this is true...now heres a question for you...so since obviously tuning is basically out of the question...how much boost do you think i'll be able to run?
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Post by PDX Cabby »

depending on charged air cooling, head porting, plumbing diameter, etc. etc... you might be able to run upto 25psi... maybe more... 18psi would likely still be pretty streetable... more than that for the track
85 Cab - 1.9L 8v, g-grind, euro dual downs to TT race w/ Borla, VWMS fuel dizzy, 2H tranny with 5th gear swap, TT short shift, FK 60/40, 15" BBS RA, rear disks... begging for boost...
turbo_cabby
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Post by turbo_cabby »

PDX Cabby wrote:depending on charged air cooling, head porting, plumbing diameter, etc. etc... you might be able to run upto 25psi... maybe more... 18psi would likely still be pretty streetable... more than that for the track

that's on a stock bottom end?
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Post by PDX Cabby »

check out the other thead
i wasn't reading closely

the shop told you wrong. For boost you need to do it as i mentioned: 16v head on an ABA bottom end.

with a stock bottom end on the combo i mentioned, you should be able to run 18 pounds and keep the bottom stock. If you get an OBD1 ABA block with forged crank and piston oil squirters, then you can take it up to 24 or so
85 Cab - 1.9L 8v, g-grind, euro dual downs to TT race w/ Borla, VWMS fuel dizzy, 2H tranny with 5th gear swap, TT short shift, FK 60/40, 15" BBS RA, rear disks... begging for boost...
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Post by turbo_cabby »

PDX Cabby wrote:check out the other thead
i wasn't reading closely

the shop told you wrong. For boost you need to do it as i mentioned: 16v head on an ABA bottom end.

with a stock bottom end on the combo i mentioned, you should be able to run 18 pounds and keep the bottom stock. If you get an OBD1 ABA block with forged crank and piston oil squirters, then you can take it up to 24 or so

the forged crank come with oil squirters? and where would you guys rec. me gettin parts from.
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Post by PDX Cabby »

i'm big on wrecking yards
85 Cab - 1.9L 8v, g-grind, euro dual downs to TT race w/ Borla, VWMS fuel dizzy, 2H tranny with 5th gear swap, TT short shift, FK 60/40, 15" BBS RA, rear disks... begging for boost...
turbo_cabby
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Post by turbo_cabby »

PDX Cabby wrote:i'm big on wrecking yards
gotcha...sorry for bein a pain in the a$$ im kinda new to the dub world...i had a 91' eagle talon TSi...19 lbs ....i went 13.2@115 shifting 1st, 2nd, 4th.....DSM=Dont Shift ME...so 3rd gear was shot...but thank you guys for being so patient
GTi 337
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