I plan on getting jun cams, extensive headwork (p&p, valve job...) and I would like to know what the safest/cheapest method would be to increase compression.

If money wasn't an issue, I'd resleave and get forged pistons, but money is an issue so what's safe and cheap...

This is what I'm thinking, type S pistons and rings, mil the head (what's safe with Jun cams, how about .0015????), flat valves, and a thinner head gasket (how thin can I go??????).

I want to make sure everything has enough clearance to keep my only car on the road.

Oh I have a 97 lude.

THANKSSSSSSSSS

 

You have everything covered. Type S pistons, flat valves, thin head gasket. You can mill the head up to 0.020" (regular head gasket) without clearance problems. A friend of mine has done it with no problems. I'm doing something similar but with a thin gasket. My motor should be ready in 2 weeks, so I'll let you know if i have any clearance issues. Oh, you will need a serious tune if you go this route as the compression will be close to 12:1.

 

1. why jun cams? I would research the lift and duration etc and decide what you want for your build instead of just getting JDM named cams.
2. i disagree with what he said ^^^^ dont waste $$ on type s pistons

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JakeIsCool &raquo;</TD></TR><TR><TD CLASS="quote">
1. why jun cams? I would research the lift and duration etc and decide what you want for your build instead of just getting JDM named cams.</TD></TR></TABLE>

you find another cam anywhere near comparable with jun cams and then you can try to make fun of them for just being jdm....in case you havent looked around there aren't many cam choices for h22s, and the jun is the only stage 3 type profile...

builds are built around cams, not the other way around....

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JakeIsCool &raquo;</TD></TR><TR><TD CLASS="quote">2. i disagree with what he said ^^^^ dont waste $$ on type s pistons </TD></TR></TABLE>

right, dont waste money on the only cost effective way to bump compression....$300 for these and flat valves and get some decent compression
or
$1300+ for sleeving and forged pistons

 

 

Gitt'em mgag7!!! That dread dude is noob.

 

JUN =

 

Thanks for all the info guys, so you think I should mil the head more versus getting a thinner gasket? I would prefer to mill the smallest amount possible so I have room to straighten this thing out if it gets warped down the road.

So the flat valves, milling and thinner gasket will not interfere with each other as far as clearance is concerned??

Is anyone here currently running a similar setup that can offer some guidance?

Is it .02 or .002?

thedread keep me updated let me know how it goes?

Do you think compression would be 12:1 even with all the headwork, P&P and valve job?

 

i would stray from milling the head, i never said that....

with cams as big as jun, and taller pistons and a thinner hg, clearances will be damn close.....dont mill it....

 

so I should be safe or would this combination (without milling) put me in the red? I'm sure someone on here has a very similar setup? Where are you????

 

where am i??

not anywhere near this setup if thats what youre asking.....and i dont know of anyone running that setup, your safest shot is to assemble it w/o milling and clay the motor.....

 

LOL, no I know your not mgags7 especially with your group buy for a turbo gasket, but I'm sure someone is and I want them to guide me through this so I don't blow up my engine.

Clay the motor huh? Sounds like a good idea, if it's what i'm thinking, but a little over my head.

 

The point I was trying to make is that buy purchasing Type s pistons you are spending hundreds of dollars to bump compression to 11:1 which does what? not much, look at the power differences between usdm, jdm and type s h22s, 190, 200, 220? If he is buying them to raise compression so he is not overcamming then I can see the purchase being justifiable.

 

Jake, I hear you, but do you realize that that the flat valves plus the thin head gasket will get him around 11.5:1....Milling the head will up the ante by about .4. This is way more cost effective than sleeving. Plus, you get to keep the benifits of frm.

 

^^exactly, nobody realizes the weight difference btw frm and iron sleeves...its huge...way bigger than the difference btw light *** forged pistons and the stock type s ones....

you could even grind those down a bit to lighten em up if you wanted....

its not hundreds of dollars....its about $300....

you are right though, he needs compression to have those cams really working....i think claying before you mill is necessary, those cams have huge lift....

and DO NOT get oversize valves, that will make it even closer for clearance...

 

Thanks mgags7, that's another option I saw for the valves and wasn't sure what the drawbacks would be but forgot to ask...

Found a write up on H-T using the trusty "Search" for claying (that mgags7 refered to) if anyones interested: http://www.c-speedracing.com/h...y.php

This is beyond my capabilities, I don't have a garage, it took me two days to change my rotors and pads in my driveway with garbage tools...

Anyone running this set up have advice on what the clearances are????????

 

I hate milling a head unless it's 100% necessary. When you mill a head and run thinner head gaskets etc you put more strain on your hydraulic timing belt tensioner. Those things have enough problems as it is, the last thing you need is to push your luck with those.

I had a shaved JG pro series head, 13:1 cr pistons and I went through valves like nobodies business. Know why? Cause I never had a tensioner last more than 12 months. Of course you can move to the H23 manual and save yourself a lot of trouble, but if it takes you two days to change brakes then you should consider having someone else build the motor for you anyway.

Also, WebCam can custom grind you a set of blank cam cores (or they could a couple of years ago) to any specs you want. Period. No need to get some radical JUN stage 3's if you'll never safely have the compression to make use of it.

I also don't suggest stainless steel valves and stock pistons... if your valves ever touch the piston tops then it's over. Lildrgn ignored me and got a set, and when the belt jumped he punched through three pistons and grenaded the entire motor. Hell, two pistons never came out even after we beat them with a hammer. This is just a personal preference though, many guys will argue with me.

One last thought:
Doing things CORRECTLY costs money. Claying, sleeving and forged pistons as opposed to milling, etc. That's something you are going to have to get used to eventually if you want to go fast. You're going to spend the money when you break stuff from going cheap. You can either save money now and pay later when the cheapness catches up to you, or you can pay now and have a strong, reliable motor.

Those are just my views on it.

 

jg, not trying to argue here, but i think that a type s piston motor can work out fairly well if done right....

using the h23 tensioner, flat faced stock size valves, jun cams, and type s pistons, i think you can take fairly good advantage of the jun cams....

a much better option is to get an h23 crank/rods and do a 95mm stroke with the type s pistons and stock valves....that will put your cr right at about 12.3 which is what those cams were designed for....

i think that is a much better option bc you wont be worrying about the tensioner, and you also can go ahead and beef up the bottom end while you have it apart, rather than spend money on milling, thinner hg, and flat valves, and put that money into some arp studs and a full bottom end balancing....

that seems like an ok idea to me, any thoughts?

 

leo had a stock block and ran JUNIII's, SMSP header/exhaust, ITB's, and tuned on AEM ems. He made great power and great torque.



Mods: TWM 52mm ITB/motorcycle sock filters/AEM EMS tuned by myself
The rest of the engine mods are Jun cams/SMSP header/SMSP exhaust with Sard muffler/UR pulleys
Head and bottem end is USDM stock w/ 10.1 compression

Our local Dynanometer reads about 10% less than Dynojets, as bone stock Preludes are averaging only 140whp on this dyno (vs 154whp on dynojet). If you want to translate my numbers to dynojet figures, multiply 206 by 1.1 would be fairly accurate.
Im also running AEM big brakes and 18" wheels, so numbers could be higher w/ stock brakes and smaller wheels setup.

same dyno that you used matt, when you made 183whp.

 

OKAY, just to let you all know, i have run into clearance issues on my h22a1. I had stock bottom end, shaved .0015, high comp 1mm ovsized valves, crower stg3 cams, with oem headgasket.... my motor got gernaded. w/e you do CLAY YOUR MOTOR! and dont save your head unelss you have to, just take .0005 off to clean it up.


OH yea, i highly recommend the crower stg3, for the 63 miles my car worked they were great, and i had a normal idle, and im using them again in my h22a all motor build that im in the process of.

 

^^you should know, running stage 3 cams with oversize valves is NEVER a good idea.....

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mgags7 &raquo;</TD></TR><TR><TD CLASS="quote">jg, not trying to argue here, but i think that a type s piston motor can work out fairly well if done right....
</TD></TR></TABLE>

Yeah, but he wants some wicked cams and "extensive headwork." So he's willing to THROW money at his top end..... but wants to go cheap on the bottom end?
Doesn't make sense.

First off about that dyno, congrats. That's pretty sick for a motor with stock internals. But for the record about that dyno, I think that it's an unfair comparison between that motor and any other motor with a stock bottom end you'll see on the street. C'mon now... smsp header? AEM? ITB's? You aren't going to see that setup much riding around your local town.
Wouldn't you think you could attribute much of those power gains from the "cams" to the ITB's and the header? That car is running more money in the header and ITB's than most people ever even think of running in a full top end build. lol I bet if you had some compression under it that motor would be so strong it'd be puking horsepower everywhere. It'd be a monstor.

Just remember, compression opens power options to you that are really not taken full advantage of with all the goodies on a stock motor.

 

well, the timing belt broke on him and fucked it all up. I havent talked to him in awhile so i dont know whats going on with the motor, but i wouldnt be suprised to see it come back to life with high compression.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JG Luder &raquo;</TD></TR><TR><TD CLASS="quote"> When you mill a head and run thinner head gaskets etc you put more strain on your hydraulic timing belt tensioner. Those things have enough problems as it is, the last thing you need is to push your luck with those.

I had a shaved JG pro series head, 13:1 cr pistons and I went through valves like nobodies business. Know why? Cause I never had a tensioner last more than 12 months. Of course you can move to the H23 manual and save yourself a lot of trouble, but if it takes you two days to change brakes then you should consider having someone else build the motor for you anyway.

</TD></TR></TABLE>

JG mild head milling (.010 to .020) is usually not a problem. Many heads are milled in that range from doing a normal valve job to get the head straight and level. The automatic tensioner on the a1 was very problematic to begin with. I had nothing but problems with the tensioner on my stock prelude until they came out with a fix for it. Most people that build H22's use the maual tensioner because of the suspect auto ones, you should have gone that route as well. The only reasons to sleeve is if you going FI, going very high compression (over 12:1), want larger sized pistons (above 87.25 mm).

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by thedread &raquo;</TD></TR><TR><TD CLASS="quote">JG mild head milling (.010 to .020) is usually not a problem. </TD></TR></TABLE>
Unless the head was milled futher than that, like these guys are talking about doing, in which case you will have problems. Remember that a block can be decked too, and that subtracts from it.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">Many heads are milled in that range from doing a normal valve job to get the head straight and level. </TD></TR></TABLE>
As a mechanic, I'm well aware of that. Anytime a head is off it should be "surfaced" by a machine shop anyway.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">The automatic tensioner on the a1 was very problematic to begin with. </TD></TR></TABLE>
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JG Luder &raquo;</TD></TR><TR><TD CLASS="quote">you put more strain on your hydraulic timing belt tensioner. Those things have enough problems as it is,</TD></TR></TABLE>


<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">Most people that build H22's use the maual tensioner because of the suspect auto ones, you should have gone that route as well. </TD></TR></TABLE>
I built my first N/A motor with over 13:1 compression almost 6 years ago. This was back before most aftermarket companies even knew the H22 existed. The manual tensioner swap wasn't a known option at that time. At least not to 99.9% of the H22 owners in the world. Of course now every block I build has a manual tensioner, but hind sight is 20/20... thanks for pointing out a mistake I made 6 years ago though.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">The only reasons to sleeve is if you going FI, going very high compression (over 12:1), want larger sized pistons (above 87.25 mm).</TD></TR></TABLE>

Two things:
1. I run 89mm on most of my blocks, unless it's boosted in which case I stick with 87. I have a block now that is about to be sleeved to 90mm. It's a pure race block that will never see the street. Ever.
2. I've seen pictures of blocks where the FRM sleeving has "gummed up" and practically melted the pistons in place. It happened after running forged pistons without re-sleeving. Was the forged piston why it did that? I can't prove it, but it certainly seems suspicious. Is this the absolute case in every situation? Obviously not... but I'll never risk it, and if anyone else who throws a large sum of money into a block, I wouldn't suggest risking it either.

Those are just my opinions... same as you have yours.