It's been a while since I posted here but I will try and keep everyone posted. I had to find out alot of information before starting this build. But it's a go. I am converting my old forged turbo 7age motor to a 20v BT 7age. I got my pistons in yesterday and am running 11.1:1 C/R with an 83mm bore. I am keeping the use of my Eagle Hbeam rods. (So maybe nitrous in the future). My goal is to build a fun reliable car with some power. With a screaming redline and ITB I am sure I will achieve just that! If anyone decides to do this build and has questions just let me know. Enjoy the pictures:)

Please explain more..
Im following

Here is the custom piston info for anyone who cares to know. Keep in mind this is for my set up. I am using a set of Hbeam rods for a Honda and a 83mm bore cosmetic 1mm thick head gasket

you have a lot of numbers there... some missing.......

What head gasket thickness are you using?

What is the final deck height?

What is the measured chamber volume?



Here is what we do know... 3.268 is bore, 3.366 is stroke, piston volume is -2.3cc


Also.... pin diameter of 21.01mm?? What rods are you using?? You said something about Eagle rods before

oldeskewltoy wrote:you have a lot of numbers there... some missing.......

What head gasket thickness are you using?

What is the final deck height?

What is the measured chamber volume?



Here is what we do know... 3.268 is bore, 3.366 is stroke, piston volume is -2.3cc


Also.... pin diameter of 21.01mm?? What rods are you using?? You said something about Eagle rods before

That would be all on the Machining paper work. I will get all that up when I go there. But if I recall we took 0.010 off the block from stock and the chamber volume was around 38cc but again going off memory. HG info as already posted.
The p/n on the Eagle rods are CRS5290H3D

yep... I missed the head gasket.... Cometic 1mm

What I'm particularly interested in is the final squish (final distance of pistons edge to flat edge of head)

CRS5290H3D - appears to be a Honda B16 rod....

Are you using a OEM crank or an aftermarket crank?

oldeskewltoy wrote:yep... I missed the head gasket.... Cometic 1mm

What I'm particularly interested in is the final squish (final distance of pistons edge to flat edge of head)

CRS5290H3D - appears to be a Honda B16 rod....

Are you using a OEM crank or an aftermarket crank?

OEM crank. Yes it is a Honda b16 rod. When she is put back together and I get final measurements I will let you know. But I want to say it was like 0.006. Again just going off memory.

Motor was balanced yesterday. Hopefully I will have back later this week. Still waiting on custom timing gear for the crank tho. Apparently its on back order. and am still debating on what I want to do for timing belt and oil pump.

I'm going to throw a guess and say you turned a 7A crank down to take Honda rod bearings and fit the big end of the Honda rod?

burdickjp wrote:I'm going to throw a guess and say you turned a 7A crank down to take Honda rod bearings and fit the big end of the Honda rod?

You guessed correctly!

You beat me to this. Good job!
Your stroke, conrod length, and and compression height don't plug straight into the calculator I had for investigating honda rods in Toyota blocks, but my numbers could be wrong.
Your numbers do come out around the right deck height, though, at 206.0702mm
Which conrod bearings did you go with? I think there were two widths of bearing. Maybe the B16A was wider than OEM 4A and the B18C was narrower. I don't remember off the top of my head. I was originally looking at the narrower ones, which would have involved narrowing the big end of the rods.

burdickjp wrote:You beat me to this. Good job!
Your stroke, conrod length, and and compression height don't plug straight into the calculator I had for investigating honda rods in Toyota blocks, but my numbers could be wrong.
Your numbers do come out around the right deck height, though, at 206.0702mm
Which conrod bearings did you go with? I think there were two widths of bearing. Maybe the B16A was wider than OEM 4A and the B18C was narrower. I don't remember off the top of my head. I was originally looking at the narrower ones, which would have involved narrowing the big end of the rods.

Neither work actually. I had to grind down a set of ACL bearings to fit.

v33sonata wrote:Neither work actually. I had to grind down a set of ACL bearings to fit.

Did you trim B16A bearings and the conrods to fit the 7A journal width, then?

burdickjp wrote:

v33sonata wrote:Neither work actually. I had to grind down a set of ACL bearings to fit.

Did you trim B16A bearings and the conrods to fit the 7A journal width, then?

Yes on the bearings..... I dont think we had to do anything to the conrods. and I am pretty sure if we did anything we ground the crank a bit to make it fit. I could be wrong. It's been years and I dont remember. I'll try and find out tho.

I also want to know.

Custom pistons with custom located wrist pin on b16 rods in a 7a block.

Im loving the innovation here.

Head anyone.......

Nice head... Lol

Did you do any thing with the head?? Or u leaving the BT head in stock form?

phanist wrote:Nice head... Lol

Did you do any thing with the head?? Or u leaving the BT head in stock form?

It's stock for now. Cams will be in the future but just want it running before I throw cams in.

If i get my hand on a 4afe or 7a flywheel i will put this engine to a test...

20V 7AGE with Poncams from Tomei?

Just an idea to throw out there.

redroku87 wrote:20V 7AGE with Poncams from Tomei?

Just an idea to throw out there.

thats the plan

v33sonata wrote:

redroku87 wrote:20V 7AGE with Poncams from Tomei?

Just an idea to throw out there.

thats the plan

Please keep us updated.

Hey Guys sorry for the delay in updating! I got got a new truck for off roading and it's been taking up most of my time. I did get my engine back fro mthe machine shop and I ordered in a timing belt gear. So hopefully here soon I will be putting her back together.

v33sonata wrote:

phanist wrote:Nice head... Lol

Did you do any thing with the head?? Or u leaving the BT head in stock form?

It's stock for now. Cams will be in the future but just want it running before I throw cams in.

The head is in stock form for now.

Those are good looking pistons.

Which timing belt are you using

kaosboss wrote:Which timing belt are you using

I havent gotten a belt yet but I am told I coult use the 4age 16v on with the new rekeyed crank pulley I have. I may have to modify the timing belt tensioner a little to make it work depending on what one I use.

Yes the 20v cam gears are closer together so you can run the longer 16v belt. On a 16v 7A you need to run the longer alternative belt.

phanist wrote:If i get my hand on a 4afe or 7a flywheel i will put this engine to a test...

Did you find a flywheel yet? I have one $100 plus ship from Jamaica. BTW what ECU you plan to use?

Got one flywheel already but too lazy to pull the engine just test the 7ag...

Planing on stock Bt ecu btw..