13:5 compression gsr

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ppiart

New Member
So I started this thread because I'm looking for advise for building my motor for 13:5:1 compression. My current setup right now is a gsr block bored to 83mm stock sleaves. Golden eagle crank, golden eagle rods, 11:0:1 JE forged pistons, ARP connecting studs, head studs ect. The head is a gsr head ported and polished with stock size forged valves, bronze valve guides, sk2 valve springs, sk2 titanium retainers, ect. Basically the head is totally fresh and built to flow air. I have sk2 pro 2 cams with sk2 cam gears, composite fuel rail, sk2 I/M with 68mm t/b. Stock injectors, sk2 2 3/4 exhaust from header back with no cat. For tuning I have aem ems v1 with the wide band air fuel kit. Basically I want to know from someone experienced what it takes to run 13:5, obviously high octane fuel bigger fuel injectors ect but I want specifics like are my cams gonna do good with that number, what octane fuel I should be looking at running stuff like that. I hope all my info will help with you giving me good feed back. If you have any questions feel free to ask
 
back in the day Import Builders/Wiseco had a set of 13.5:1 pump gas pistons, made 201whp in a B20/vtec with S2S2 cams and a non-ported GSR head for me. I believe I was only running 750 injectors, not for sure though.

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1/14/05...old school like a mo'fucka! lol...


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I've still got the cam gear settings, too...+4* both intake and exhaust.



I've still got one of those pistons sitting around somewhere. It's melted to the connecting rod :D
 
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Wil, were you using PRO series cam gears on that motor? if not, his cam settings may be different. Either way its best toproperly DEGREE the cams. depending where you're from you may have a hard time finding someone who will do this for you.

as far as injectors, you probably wont need anything over a 550 (thats probably a lot higher than you'll actually use in fact)

your cams will be fine. my concern is who did your port work?
 
I would run E85 for my fuel. 105 octane and cheaper than 87 octane. You'll probably need 750's or so.
 
Wil, were you using PRO series cam gears on that motor? if not, his cam settings may be different. Either way its best toproperly DEGREE the cams. depending where you're from you may have a hard time finding someone who will do this for you.

as far as injectors, you probably wont need anything over a 550 (thats probably a lot higher than you'll actually use in fact)

your cams will be fine. my concern is who did your port work?

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Regardless of brand, 1 degree of advance = 1 degree of advance...unless you've got some chitty knockoff eBay gears.
 
Cam gears are skunk2 pro series cam gears and also I had a place called hutchins performance do the machine work on my head. He did the heads on my buddys dad's 70 challenger and also is popular for building hotrod motors but has experience in imports as well
 
Did you get any flow data on the head? Having hard numbers to follow is the best way to pick out your cams. Just sayin the head flows like mutha fucka isnt enough info lol.
 
i made the mistake of going with a hot rod shop to do the port work on my first build. literally the headwork held me back when it was supposed to help.

hopefully you wont be in the same situation
 
And as far as cam gear markings, when talking about tuner series cam gears vs. pro series cam gears their markings do not represent the same increment.

ALL M0T0R said:
Tuner series gears are 1 cam degree = 2 crank degrees

Pro series gears are 1 cam degree = 1 crank degree.

ALL M0T0R on HT is a well known engine builder/tuner and knows what he's talking about...
 
with 13.5:1 you better make more that 201whp. if your planning on running this on pump gas I would go with a 12-13:1 nothing higher unless you can tune on E85.
 
So even with the fact I'm 20 years old young and dumb, any thing over 13:1 is just stupid?
 
And as far as cam gear markings, when talking about tuner series cam gears vs. pro series cam gears their markings do not represent the same increment.



ALL M0T0R on HT is a well known engine builder/tuner and knows what he's talking about...

What?

1 camshaft degree will ALWAYS equal 2 crankshaft degrees...the crank rotates at twice the speed of the camshaft, so for every one complete 360* rotation of the camshaft, the crank has rotated twice...changing your cam gear brand/model doesn't change the gear ratio between the camshaft and the crankshaft...

how many motors have you actually built, rather than just reading about someone else's build? And what kinda work do you do on a day-to-day basis, Brian?
 
He's probably talking about the timing markings in the cam gears which can differ 1 mark meaning 1 degree or 1 mark meaning 2 degrees. I think your picture pretty much settles it for those gears.. lol
 
He's probably talking about the timing markings in the cam gears which can differ 1 mark meaning 1 degree or 1 mark meaning 2 degrees. I think your picture pretty much settles it for those gears.. lol

Werd.

Which wouldnt matter anyways. The only difference is, with one set you would adjust to the fourth mark and with the other it would be the second mark. Pretty simple.
 
Werd.

Which wouldnt matter anyways. The only difference is, with one set you would adjust to the fourth mark and with the other it would be the second mark. Pretty simple.

Right...which is why I didn't say 'move it two marks to the left', I said 'move it four degrees advanced'.
 
Right...which is why I didn't say 'move it two marks to the left', I said 'move it four degrees advanced'.

Lol, ya I followed you on that. Not everyone else did though.
 
Not everyone is as badass and smart as you Wil. I was simply trying to help the guy out and letting him know that one persons settings may or may not work for him and that he should have the cams DEGREED regardless of what cams and gears he's using. Degreeing > using anyone elses advice on where to set his cam gears.
 
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