Extending the firewall for stock v8 accessories Options

[86motoman]

Is there enough room behind the seats to cut the firewall off of a parts car and shape and weld an extended firewall to fit stock v8 components?

[ClayPerrine]

You need to look at what was done to the Alien. The firewall was moved forward to allow the fitting of the 928 engine.

[Mueller]

depends on a few factors such as do you "need" to have your seats all the way back?

normally for V8 conversions, it's the waterpump and balancer that are the issue, since those are pretty much in the middle, there should be no interferance with the seats....

what you want to do has been done before...modifications like this normally are either done really nice and professional like or look like hack jobs which always stick out it peoples minds when the talk of conversions comes up...

the key thing it making sure that the integrity of the firewall is as good or better than it originally was........

[MikeP]

The place you'll run into the biggest hassle is the tunnle with all of the controlls and little tubes etc running through it. It is right in the middle of a V8 pulley assembly which is why most guys run those crappy 6cyl dampers with the v grooves. If you are going to run a stock damper pully system this is where your biggest headache will be.

[John2kx]

To add to what Mike has said, depending on how many accessories you are going to hang off that small block, the accessories (alternator, a/c compressor) would be better positioned down low. If you were to hang them like most small blocks (up high), you'll now be in the upper seat area to make them fit, and probably limiting the car to be driven only by those vertically challenged.

I can see putting the stock harmonic balancer and water pump on with the addition of a "bubble" in between the seats to make it fit, but you still have the issue of a alternator or whatever else you may want to install. Using the stock harmonic balancer does put the belt groove forward which would require the alternator (at a minimum) to be shifted forward to match up, and even if alternator were moved forward, you would still need to provide clearance at upper/lower seat area to make it work. This may be hard to visualize without a pic but look at a v8 equipped 914 and checkout the valve cover area. If you were to install a alternator above and forward of the valve cover, your belt would be located 8" or so in front of valve cover........or about in the same position as your right ear.

Not to say what your asking is impossible, but the conversion folks may have taken this approach years ago if it were feasible.

You may find the attached pic of use. This is a Renegade serpentine setup with their small harmonic balancer, alternator, a/c compressor and water pump. Note: with this setup, I still had about 2" of clearance from front of harmonic balancer to lower bulkhead, below engine shelf.

John

[marks914]

I looked into doing this when I did my V8 conversion, espescially at what red dawg racing did. I found that it wasn't worth the money and effort. If you are looking to save some $, do it somewhere else.

Just my 2 cents
Mark

[John2kx]

Here is the typical damper Mike mentioned.

[914GT]

QUOTE (MikeP @ Aug 2 2005, 11:45 AM)

most guys run those crappy 6cyl dampers with the v grooves.

Not sure why they are crappy. I'm using one and it works fine. However I did have the rotating assembly balanced.

[John2kx]

QUOTE (914GT @ Aug 2 2005, 11:03 AM)

QUOTE (MikeP @ Aug 2 2005, 11:45 AM) most guys run those crappy 6cyl dampers with the v grooves. Not sure why they are crappy. I'm using one and it works fine. However I did have the rotating assembly balanced.

I used the modified damper for 6000 miles without issue and saw 6000 rpm on many occasions. My internals were balanced as well.

John

[John2kx]

QUOTE (MikeP @ Aug 2 2005, 10:45 AM)

The place you'll run into the biggest hassle is the tunnle with all of the controlls and little tubes etc running through it. It is right in the middle of a V8 pulley assembly which is why most guys run those crappy 6cyl dampers with the v grooves. If you are going to run a stock damper pully system this is where your biggest headache will be.

Here's the area Mike is talking about. There is more clearance between the 6 cyl. damper and the lower bulkhead than I remembered. Looks like you could go 2" larger in diameter and have about 4" additional clearance before making contact with lower bulkhead (using modified 6" as reference).

The lower section may work without modification but you still need to route at least one belt to spin a alternator, if this is your only accessory. If you mounted it below the engine shelf, you may be able to just modify center area (between seats) to provide water pump clearance.

John

[John2kx]

One more from the other side.

[914GT]

What is being referred to as a 'modified' damper? Are they actually modifying these to add V-belt grooves?

[John2kx]

QUOTE (914GT @ Aug 2 2005, 12:22 PM)

What is being referred to as a 'modified' damper? Are they actually modifying these to add V-belt grooves?

I'm not sure of all the mods made but did see where the back side was machined down to prevent contacting timing chain cover.

[914GT]

Seems like more work than necessary when you can buy a stock GM balancer with v-belt grooves, then add a shim or two to space it out.
I'm referring to v-belt balancers here, not the serpentine system shown in the pics above.

[86motoman]

All of this information is great guys! Thank you.

It seems like it is more of a hassle than it is worth because of the alternator.

I was entertaining this idea because I am going to put in the new generation chevy small block. I will probably use the 5.3 truck engine.

Does anybody know if the above renegade serpentine system would work with the new generation small block chevy?

[bondo]

QUOTE (86motoman @ Aug 3 2005, 09:43 AM)

All of this information is great guys! Thank you. It seems like it is more of a hassle than it is worth because of the alternator. I was entertaining this idea because I am going to put in the new generation chevy small block. I will probably use the 5.3 truck engine. Does anybody know if the above renegade serpentine system would work with the new generation small block chevy?

Chances are it won't fit.. but it isn't THAT hard to make the stuff yourself. I made my own alternator mount because I'm using an odd engine (1993 LT1). If you use an electric water pump it simplifies things even further. Just make darn sure the engine itself will fit, then work in your accessories where they fit. You may end up having to cut out the stock engine shelf (not necessary with a renegade kit), but it does no good to leave it.. many people cut it out just to save weight and make more room.

[BIGKAT_83]

QUOTE (86motoman @ Aug 3 2005, 12:43 PM)

All of this information is great guys! Thank you. It seems like it is more of a hassle than it is worth because of the alternator. I was entertaining this idea because I am going to put in the new generation chevy small block. I will probably use the 5.3 truck engine. Does anybody know if the above renegade serpentine system would work with the new generation small block chevy?

The 5.3 Liter Gen III Truck one will not work. Its way too long. You can use the one from a Ls1 Corvette 97 and newer. This puts the belts back over 2"

You will need to use the alternator mount from a 98/02 Ls1 F-body car and make some mods to it. This mounts the alternator low on the block.

This gives you more clearance at the HB than with a older SBC with the 6 cyl. balancer.

You won't be able to use the truck intake. Its too high.

If you used the new intake and carb kit from Edelbrock and GM. You can mount a genIII engine in a 914 without cutting anything at all in the engine bay.

Bob

[MikeP]

I'll clarify my comment about "crappy" 6 cyl dampers. I too balanced my internals but I built my engine to turn 8k so I had ATI make a custom Super-Damper with a serpentine shell on it, I think they may sell it now as a stock item for LS1 engines, have I seen royalty penny 1 you ask. No. Pics of my setup are attached

[MikeP]

Also my motor sits much lower than the ones picturedsabove so my balancer is centered just above the engine shelf.

[BIGKAT_83]

ATI does make a balance for the GenIII. They make them in stock configurations for the truck,Fbody and vettes.

I had used a stock 6 cyl. harmonic balancer from a 3.8L V6 with a serpintine belt setup on my 914 V8 and this worked fine with no clearence problems at all. It fit on the SBC V8 with out using any spacers or anything.

Something to think about with using that 6cyl. balancer is how close you are to that when you are spinning that engine at 7.5k RPM. I changed mine to a ATI also.

If you read the NHRA drag racing rule book it does not allow a non SFI approved balancer on any car that runs a 12.99 sec or faster ET. There must be a reason for that.


Bob (IMG:http://www.914world.com/bbs2/html/emoticons/smilie_pokal.gif)