Shaving the head

[Justin86]

I was thinking about shaving my head to change the compression and get some more power. I'm also plaining on putting on a turbo over the summer and wasn't sure if shaving the block would hurt the performance of the turbo. I will run low psi untill I can afford to upgrade to internals. Should it make a difference or not. Also I have acces to a mill so I was thinking about shaving the head myself. Is this a good idea to save money or not.

[‹^› ‹(•¿•)› ‹^›]

FUTURE MODS
EFI, (B18C + turbo + NOS=500hp) :huh:
:wtf:
:eek:
:gay:
:bh:

[turfnnsurf]

I'll tell you this Justin, By the first week of MAY, I will be getting back my spare A20 cylinder head & intake manifold from a port and polish job plus a head shave of 25 thousands to raise compression. I have some dyno time booked for a baseline before the new head and after so I'll post the results for you to decide if it's worth it after that... By the way if you are able to do a turbo on you car this summer I will be very interested in how you do it!!!! Also will you be using Sean's GM ECU upgrade??



Brad

[1988starter]

Originally posted by ‹^› ‹(•¿•)› ‹^›
FUTURE MODS
EFI, (B18C + turbo + NOS=500hp) :huh:
:wtf:
:eek:
:gay:
:bh:

Yea I have been thinking the same but any way.

If you want to increase compression you don't want turbo generally when you go turbo you lower compression.

[‹^› ‹(•¿•)› ‹^›]

Originally posted by 1988starter
Yea I have been thinking the same but any way.

If you want to increase compression you don't want turbo generally when you go turbo you lower compression.

I was going to say the same thing, but his sig says b18, but he just stated that he is planing a a20 turbo set up.. which one?

[Justin86]

I'm going to run a simple turbo set up on my A20 untill I save up the funds to do sweet B18C setup. Remember I'm still in high school so I'm not loaded with money to do what ever I want. I plan on spending around $600 to do the turbo and I will do all the work on the turbo myself to save money. It has been done before for around that price without doing internals.

[Sean]

It has been done before for around that price without doing internals.

ok first off your car in an lxi. you make roughly 130hp. depedning on model year etc.

secondly. you might keep thinking HP. turbos dont really add HP. the leverage Tq.

for every 1 psi of boost you add to the a20a. you basically ad 15% more Tq. by the time you hit 8 psi you making WOW over 230ftlb of TQ at like 3500rpm. trust me that much Tq is addictive.

remeber

tq x rpm / 5250 = HP.

for example a b16 makes 106ft of Tq.

106 x 5500/5250= 111hp. raise the rpm up a bit and it make more HP.

now if you apply the same formula to a turboed a20a

230 x 5500/5250= 240 hp.

think about it. the better part is that youll have a fairly flat TQ curve with a properly sized t3 which will make driving this car so much more pleasureable. no replacemnt for displacment i dont care how much Vtec you throw at it.


also if you run 8psi of boost without a reliabel way to reatdr timing ( no the MSD BTM is not a reliable device) then your gonna break the motor.

check out my ecm package. its got room to grow and offer serious benefits. even the SDS and haltech cant compete. and if you plan to run big mods later forget about using a stock p28 or p30 they just dont hack it.

[Justin86]

Hey thanks Sean for the info. Also my true is a Lx soon to be EFI and a factory sunroof when I have the $.

[Justin86]

Originally posted by ‹^› ‹(•¿•)› ‹^›
FUTURE MODS
EFI, (B18C + turbo + NOS=500hp) :huh:
:wtf:
:eek:
:gay:
:bh:

Hey is there something wrong with that. I'm working my way up to my altimate goal here. That is the setup I will run to reach 500hp since you have to get into all of the advance computer crap to run +500hp without the NOS. So I will have around 450hp with just the turbo and then a shot of NOS to get above 500. I'm not a rocket scientist so I'm not a 100% sure on this but I belive it can work. Corect me if I'm wrong. :pissed:
"Don't hate the player, hate the game":flip:

[‹^› ‹(•¿•)› ‹^›]

Originally posted by Justin86
"Don't hate the player, hate the game":flip:

You mean you want one of these..

http://images.cardomain.com/member_img_b/260000-260999/260423_7_full.jpg:wave:

I HAVE ONE , YOU DON'T...

[Sean]

to be honest the goal of 500hp is a bit unrealistic. 350hp is doable on a working mand income. but $500. nah i dont think so. i mean i can make the GM ecm support it. that problem is that the short blokc of a b18 aint gonna hodl up.

the a20a is tested with stock rods and forged pistons to be safe at 350hp. thats enough for solid 11's in the 1/4 mile. thats more then fast enough.

[YK86]

Just keep in mind that if you shave the head too much, you will retard the cam. The head will sit lower after you shave it so the excess timingbelt slack is removed by the tensioner which then retards the cam. I forgot how much you had to shave it for it to affect things but just throweing that out there. I was talking to a machinist when I was thinking about doing it and he said shaving the head originated from domestic OHV engines where the cams sat in the middle of the motor and were not affected by the shaved head. But it's different for OHC motors.

[A20A1]

what about adding material to the top of the pistons to raise compression... I've seen a few with triangle like slopes on the top instead of just a flat surface.

[Justin86]

I never thought about the timing belt. That could become a problem.
I know that it will be pricey to do 500hp, and people are giving be crap like it can't be done. I have seen it done before in other cars so I know it is possible to reach +500hp. With just an average income it might be too much money, but when I get dine with college I will be making at least 60K starting out. Maybe more depending on which field of Engennering I decide to go into.

[YK86]

I forgot to mention that you can fix the timingbelt problem with an adjustable cam gear.

[Justin86]

I didn't know that there are adjustable cam gears for the A20. How much $.