I am having trouble finding any higher than stock compression pistons for a .040 in./1.0 mm overbore piston for D16A6 and need some help.

My racecar block was already bored and prepped for .040 over with flat top pistons but the rules gave us an increase to 12.0:1 compression for 2006. So far, I have only found higher compression pistons in .020 in/ 0.5mm overbore. I'd rather not have to start fresh with a new block if I don't have to. I have searched and looked at alot of threads and not found this info.

If I need to do it, does anyone have experience in having custom pistons made?

 

Any thoughts on .040 in/1.0mm overbore higher compression pistons?

I can't tell if I am SOL or just that Christmas Eve was a bad time to post.

 

the rules wont let u call a company and have a custom piston cut?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Supernatural &raquo;</TD></TR><TR><TD CLASS="quote">the rules wont let u call a company and have a custom piston cut?</TD></TR></TABLE>
The rules are fine with that but I am not sure that my budget is.

That is why at the end I asked if anyone had experience with custom made pistons. If they cost less than the several hundred dollars that it would cost to get and prep a new block with a 0.5mm overbore and then buy off the shelf overbore pistons, then that will be my best bet. I sent an email to JE/SRP Pistons asking about custom options a week ago and got no answer so I'll resend after the new year.

Anyone know what custom pistons cost? I am in a bit of a corner.

 

The 1mm over Topline P-29 piston, the 88Intega is out of stock at all depot's. Tried to get some last week. Maybe some one on the "D" boards has a set. I got the .5mm ones.

 

mill your head???
try running a 2 layer Y8 gasket???
buy some Omnipower flatfaced d-vtec valves and do a valve job/bowl blend to compliment the 1mm oversized valve compared to the nonvtec valve.
all these things would allow you to retain a nice flat piston and would probably fit into your budget.

 

The D-vtec valves do not fit the A6 head, lengths are wrong. What class are you running?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DonF &raquo;</TD></TR><TR><TD CLASS="quote">The 1mm over Topline P-29 piston, the 88Intega is out of stock at all depot's. Tried to get some last week. Maybe some one on the "D" boards has a set. I got the .5mm ones.</TD></TR></TABLE>
I am not familiar with that piston if it could be found. What kind of compression does that offer? Is there a thread or info where I could read up on it? Although I have built a number of engines Improved Touring, I am still pretty new to being allowed to make many changes in piston, cam, etc. I did some reading on http://www.d-series.org but didn't find anything I could use yet. Are tehre other D Sereis boards?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by lohatch &raquo;</TD></TR><TR><TD CLASS="quote">mill your head???
try running a 2 layer Y8 gasket???
buy some Omnipower flatfaced d-vtec valves and do a valve job/bowl blend to compliment the 1mm oversized valve compared to the nonvtec valve.
all these things would allow you to retain a nice flat piston and would probably fit into your budget.</TD></TR></TABLE>
The head is milled a bit and the blocks is slightly decked but I am told there is no way I am going to get two points of compression with head and block and without pistons. I need to keep my stock valve size and can't do any port of bowl work more than basic matching 1 inch each way from the manufold gaskets into the head or the intake manifold.

DonF- I am racing in SCCA's F Production under the Limited Preparation rules greatly restricting a lot on engine work.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DonF &raquo;</TD></TR><TR><TD CLASS="quote">The D-vtec valves do not fit the A6 head, lengths are wrong. What class are you running?</TD></TR></TABLE>

good info don, i didnt know for sure. thought it would be a cheap alternative for him if the rules allowed it, if it would have worked.

 

Lee, ther is a pic of the pistons in SMSP's thread on his econo D16 build, here on the all-motor forum. They are 88-89 Integra. I am building a G prod. engine for a customer, that is why I asked, lower comp. ratio and only .360 at the valve.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DonF &raquo;</TD></TR><TR><TD CLASS="quote">Lee, ther is a pic of the pistons in SMSP's thread on his econo D16 build, here on the all-motor forum. They are 88-89 Integra. I am building a G prod. engine for a customer, that is why I asked, lower comp. ratio and only .360 at the valve. </TD></TR></TABLE>
I read Dave's thread with the .25 mm overbore but there wasn't any info on the compression outcome. It does appear that there is more contour in that piston than the stock D16A6 flat tops but I don't know anything about the wrist pin to face height comparison. I have not seen that engine listed in most of the aftermarket, high compression piston listings and would consider it far too lucky to find my target 11.0-12.0:1 compression with an off the shelf overbore piston from that car. I do vaguely recall people mentioning them in the mid-'90s as a cheater piston for an ITA '88-91 CRX but they were readily visually identified just by looking. That is not my style so I haven't thought about them in nearly a decade.

I am allowed a .450 lift max at the valves and I don't know which cam to use yet but I was saving that for a seperate thread once I get the piston issue sorted out. At first there seem to be a lot of brands making D-series but most appear to be vtec only. If someone has compiled a list of A6 cam options, that is olso on my immediate shopping list.

 

Lee, pin to deck is the same, and yes that is the old ITA cheater. I will check again this week if any are avail. in .040 as I need a set also.

 

I got some P29 40over from Topline about 2 months ago.