Stroked96Bowtie

I read all over that the typical rule with these LT motors is 9:1 for DCR and to be able to run pump gas. The setup Im looking at shows to be 10.42DCR, Im curious what some opinions are for this setup on the street and how far back do you think it would need to be tuned to run pump gas. Im thinking I will need seperate tunes, one for street and one for race.

Im willing to put racefuel in it at the track but want to run on pump gas around town.

NightTrain66

really depends on how they came up with that DCR.

If it is 13 to 1 CR and has a cam with about the size duration you need for your gear, stall, weight, etc, probably have to pull some SCR from it with different pistons. If the heads are milled all to hell and have 48-50 cc chmabers, a head swap can do it.

It might be a cam that can be fudged on and delay the IVC to bleed off some DCR. If this is the case, get with but Bret Bauer or what ever cam designer you trust and have them work out something for you.

What cubic inch, pistons, head gasket thickness, chamber volume, SCR, cam specs (and I uess gear, stall weight, shift RPM, etc if willing to change cam)..

Not sure what all you are working with or what all you are wanting to change but fill in the blanks and someone can help you out.

Lloyd

Stroked96Bowtie

Thanks Lloyd!

Heres what Im looking at:
no looky looky

Cam specs:
no looky looky you missed out!

Duration @.015 Tappet lift
no looky looky you missed out!

Valve Timing @ .050
no looky looky you missed out!


Specs for the cam installed:
no looky looky you missed out!

Duration @ .050: no looky looky you missed out!

Gear: no looky looky you missed out!
Stall: no looky looky you missed out!
Wieght: no looky looky you missed out!

I have a bigger cam but was going to go with this smaller one to help with the comp...although it doesnt seem to make much of a diff. Im walking a fine line here...of course get the most power on pump gas and willing to run racefuel at the track. Its hard to call it a 'street' car if you have to run racegas in it ALL the time

tomcowle

Use a 5.85" rod, it gives a much better ring package.

Stroked96Bowtie

The reason for the parts list above is because its a shortblock Im looking at...its complete already. If it wont work as is Im going to have to rethink the purchase.

The shorter rod would also decrease the DCR too I believe.

ulakovic22

What is the deck height on the block? Is it zero decked or are the pistons still in the hole?

Stroked96Bowtie

The build sheet shows 9.00 for block height...deck height of .005.

WS6 TA

Ok, I’m sure that you know there are dozens of ways of lowering static compression but I’m guessing that those just won’t really work for what you’re doing. Otherwise, you can lower DCR with a bigger cam….

That being said, lets assume that you have to stay where you’re at, can you run it on pump gas? Well, that depends. The trick would be to keep the load down on the engine on the street. There are people that sneak out on Friday nights with their 13:1 carbed race cars and get way with cruising on pump gas. This would be easier with fuel injection. The trick is STEEP gears, a high stall converter and to make sure that it stays cool.

NightTrain66

either swap pistons and drop some SCR or go with a larger cam BUT the duration on the cam you have seems about right for what you have described your cars set up to be.

I think a cam big enough to get the DCR in the 9.0 range (if that is your target) would require alot more gear/stall than you have.

I would drop the SCR with a piston swap and use that cam since it seems like what your set up needs.

Lloyd

Stroked96Bowtie

Id hate to have to put more gear and stall in the car...Im going to see what this other cam will do with it..its a 'no looky looky you missed out!' lift...bigger than I wanted. If you think that bigger cam will require more gear and stall I might just stick with the smaller one and really make Moe work for his money tuning this thing

Stroked96Bowtie

Would someone mind double checking the SCR/DCR on the specs above...I think I had something wrong in the calculator...Im getting 11.4 (DCR) now. Yes I know its going the wrong way.

Stroked96Bowtie

Guys I apprieciate your inputs...this setup is just not going to work for what I want...which is a pump gas street car. I backed out of the deal...looking for another deal now

AutoRoc

Watch the rods and cam lobes...I had issues..

6" rod worries me also. I did them in a 396 and a 1.07 CH isn't pretty, like these guys are saying. 5.85 all day. I'd feel safer spraying mine if I did a 383 with 5.85's.