hello guys

I am building a blowthrough ( carbed ) twin turbocharged LT1
and I will use MSD distributor ( SBC Style ) ( NO OPTI )+ soild roller cam

what timing sets can I use
- With the stock Water Pump ?
- With Electric Water Pump ?
- can I use SBC timing cover ?


thanks

 

If you use a stock water pump, you must use a stock type gear that has the w/p drive on it.

If you use an electric pump, you can use any SBC type timing set.

I would say it might be possible to use an SBC cover if you use an electric pump and no opti. If you use the LT1 cover, it will have to be clearanced on the inside when using a timing set like the Cloyes double roller. You will probably want a 1995 LT1 timing cover as it will be able to accomodate the LT4 distributor block-off plate and won't have a crank sensor hole in it like the 96-97s do.

 

hello shoebox

thanks for your reply

are the LT4 timing sets as strong as Cloyes double roller

I mean is it safe to use it with a soild roller cam shifting at 7000-7500 rpm ?

 

IMO, if you are going to repeatedly go those rpms, I would use the Cloyes and electric water pump. No sense in having in to spin the water pump that high and have the extra tug on the cam gear (that you would with the LT4 ED set). Could you still use the LT4 ED set (maybe you already have one?), even with the electric pump? Yes and I would say it is probably as strong as the Cloyes set.

 

Go with the electric pump and a cloyes true roller. The pricing difference versus buying a lt4 ED set is staggering in favor of the electric pump and the reliability is even better.

You cannot fit a regular SBC timing cover on. The whole bolt pattern is different and the cover is designed differently. I ran into this when we swapped heathers car to carbed/ distributor.

I take it this is going in an RX-7. I've been working on my Twin turbo EFI for awhile now. Should put down near 950 hp or so. Got the car weight down to around 1100 pounds too

If you want any specifics on the swap or have any questions, feel free to email me or PM me

-Shannon

 

Yes its safe..... I like the Extreme Duty. Been fine on my engine, which has a solid roller and redlines above 7,000rpm. Also worked fine on George Baxter's 1,125HP, 8,000+ RPM LT1. Both used the stock water pump. When you are making the kind of power you can make at 7,000+RPM with a big power adder on top of that, the extra coolant flow is needed, IMHO. I did have some of the extra metal machined out of the cam sprocket to keep the rotating mass down.

 

I don't mean to hijack this thread, but I'm running into the same problem. There seems to be two solutions. Either fabricate a plug for the Opti hole or buy the plug that GM Performance Parts makes. What was your solution Shannon.

 

shoebox

I will spin it that high only in the strip
and since I don't have any of them right now
so I am comparing

Cloyes $$ 80 + Summit EWP( which flows about 30 GPM and I don't think it is enough for my motor ) $$ 180 = $$ 260
and
LT4 ED set $$ 246 from Summit + stock WP


NOMAD

it is cheaper for me to buy the ED set since I already have a new stock WP
and I do have both LT1 and sbc covers so it is not an issue



Injuneer

thats nice
how much did you machine the sprocket ?


sseeya

I will fabricate one




thanks a lot

 

Not a lot......

http://members.aol.com/Fredrick518/Photos/newfront.jpg

 

thanks