7a + Bt 20v

**Panda_Tureno86** · 07-04-2009, 01:24 PM

Hey guys
Just wanted to know what are the parts I need to get these two bits to work
I have a 7A bottom end
A complete blacktop 20V
which I plan to put together.

Been reading on the forum that I will have to use a 20V oil pump and waterpump??
I have a 16V timing belt ready.
Any other bits that I have to get??

Also been reading about rods for the 7A.
Which one to go for? Pros and cons?

If I run some high comp pistons like TODA's, would I be getting too much compression?
Also which head gasket to use?
I have a 20V and a 16V one. TRD 0.8 mm.

Any input would be great.

Thanks heaps

**The Last Streetfighter** · 07-04-2009, 01:35 PM

Inspiration: http://www.twincam.info/index.php?sh...=18070&hl=7age
http://www.twincam.info/index.php?sh...=37182&hl=7age

**Mooro** · 07-04-2009, 02:39 PM

I can't help much, but I've always thought this would be a nice setup. If you go ahead, be sure to keep Toymods updated with progress and results...would be very interesting.

**KARNAGE** · 07-04-2009, 11:23 PM

use head gaskit to suit the head so if you are using the 20 valve bt head use the 20valve gaskit. Not intirely sure but i dont think the 16timing belt is going to work at all, it has the wrong number of teeth on it to work with the bt timing.

**Panda_Tureno86** · 08-04-2009, 05:16 AM

Is that a definite answer?
I have been reading so much about the 7A and 16V and 20V head.
it seems that there are so many possobilities with just the timing belt.
some said about Porsche's, some said 16V.

**Hiro** · 08-04-2009, 08:05 AM

Originally Posted by Panda_Tureno86

Is that a definite answer?
I have been reading so much about the 7A and 16V and 20V head.
it seems that there are so many possobilities with just the timing belt.
some said about Porsche's, some said 16V.

Porsche timing belt is for a 16v 7AGE, from what I've heard the 16V timing belt is what you need for a 20v 7AGE. Reason for this is the 16V head is wider than the 20v, so the cam gears are further apart and hence uses a longer belt. So using a 20v head for a 7AGE requires a shorter belt than a 16v 7AGE, but the increase in deck-height means that the 16v is the right length.

**Mooro** · 08-04-2009, 08:36 AM

With headgaskets, I can't remember exactly but using stock blacktop pistons and a 7age headgasket results in a CR up around 12:1. If you high comp pistons as well it probably get a bit high....maybe OK if using the 4age headgasket.

**KARNAGE** · 08-04-2009, 09:49 AM

is this a street car? cos compression that high is going to be F*^CKED when running 98ron my old black top was mainly a track car that sometimes went on the road and before i turboed it she was running 11.8:1 and it didnt like 98ron much at all

**Mooro** · 08-04-2009, 09:56 AM

Yeh personally I would do something like stick with the stock blacktop pistons and the 0,8mm TRD gasket or even just the thicker 4age gasket as a nice cheap comprimise

**KARNAGE** · 08-04-2009, 10:00 AM

yeah i agree it would make the engine life longer cos all the high comp engines i have been around have never lasted all that long, but they were pushed pretty frickon hard

**Hiro** · 08-04-2009, 10:56 AM

Originally Posted by Mooro

With headgaskets, I can't remember exactly but using stock blacktop pistons and a 7age headgasket results in a CR up around 12:1. If you high comp pistons as well it probably get a bit high....maybe OK if using the 4age headgasket.

No such thing, it'll either be a 7AFE or 4AGE gasket

**Mooro** · 08-04-2009, 12:04 PM

haha...you know what I meant...7afe gasket (0.6mm) vs 4age gasket (1.2mm)

**Panda_Tureno86** · 08-04-2009, 12:46 PM

so if I am to use a 4AGE gasket... it would be a 16V one???
that works for a 20V head as well??
or 7A??

**Panda_Tureno86** · 09-04-2009, 06:18 PM

speaking of CR the hondas are running like 12:1 on the street cars.
they dont seems to have any problems.

**cooter** · 11-04-2009, 02:06 PM

have you seen this page??
http://www.turbofast.com.au/mr2.html

"Only major problem assembling the engine was the timing belt. We used the 20v belt and had to reduce the cam belt idler pulley diameter by 4mm and lengthen the adjustment slot. The timing cover had to be modified so the idler pulley would not touch. The crankshaft timing belt pulley had a new keyway cut, to correct the cam timing which was out due to the belt length and the 14mm higher deck height of the 7A block."

this one might help too. has good compression figures.http://www.toymods.net/forums/showth...ktop+4age+7age

craig