evilg

Hi Guys,

I am seriously thinking about going single turbo (GT35R) for obvious reasons.

In New Zealand, a lot of tuners say that you *Have* to dowel your engine if you want to go over 330 (ish) horsepower at the treads.

From what I have read that involves drilling holes through the engine block and adding long bolts in oder to strengthen the rotary "sandwich" - reduce twisting, and seal things better.

I have looked at many things on this forum, and I just don't see much mention of this procedure.

So what I am asking, is: Is there anything that needs to be prepped on the engine to put down roughly 400 HP at the wheels?
Obviously I have all the supporting mods necessary (PFC, Extra fuelling, Intercooler, intake, exhaust, HKS twinpower, etc), I am just concerned with engine prep.

My current engine has about 4000 miles on it, with a mild street port - standard seals.

Thanks in advance.

BADSVN2000

Hey bud, I have a friend that just had his engine built for drifting, he will be making 550+HP and he has a massive bridgeport with centre bearing and his engine is dowelled etc. From what I know dowelling does make your engine stronger and depending how it is done and who does it it can weaken the through bolt holes by drilling them larger to fit bigger, stronger through bolts. However I have been told that thee is a company in Aussie that makes new through bolts that replace the stock ones, they are slightly wider than stock so they are really snug and reduce movement more so and you dont need to drill out your engine to fit them.

I would call Tony from RX7 Heaven here in Auckland and talk to him as I trust him more than any other Rotary Builder in NZ, he is open to answering your questions, very clued up and a good guy overall.

He will be building my next motor unless I decide to do it myself as its either him or me.

GoodfellaFD3S

iTrader: (213)

They are wrong, wrong, wrong.

I've been making 425+ rwhp for the last 3 years with a stock block (when it comes to dowels anyway). Don't bother doweling your motor unless you want north of 500-550 rwhp.

Internally, your motor is ready for the 35R

ziig

iTrader: (1)

i am building a drift car for a guy right now and all i am doing is using the bolt on dowel kit from mazda trix, 500 bucks , it is stronger than stock bolts. increases strength and reduces engine expansion...now you can use the other dowel kit they sell which does require you to drill out the existing holes to a slightly bigger bore to fit the dowel, but i think for street use at about 550 HP these will be enough........

Gorilla RE

iTrader: (1)

If that is the case, I wouldn't have my car tuned by ANY of "those tuners".....

The answer is NO NO and NO you do not need to dowel your engine.

-J

evilg

Hi Guys,

Thanks for the responses. I figured the engine was probably ready for the 35R (Cheers Goodfella!!)

I think the problem here is that the rotary community here is quite close knit, and the tuners are paranoid about blowing up someone's engine and getting a bad rep. That and they can charge the earth to "prep" your engine when you don't really need it.

BadSVN I have talked to Tony in the past, and he will probably be doing my dyno tune - although he hasn't done a lot of PFCs (was mostly a microtech guy) - I think it was two of the "other" tuners in the immediate Auckland area that suggested dowelling as a must...... One of the others (PM me if you want more info on that) refused to turn my boost up further than 11 PSI - and told me not to bother installing my KGparts kit with 1680 secondaries. - He wasn't willing to tune me past 300 RWHP .... WTH?

Anyone else want to chime in and give me something else to think about, I am open to suggestion from the pros.


Thanks again guys!

Howard Coleman

iTrader: (6)

someone is either very misguided or trying to sell you something.

neither (of the above) makes for the start of a good relationship w an engine builder.

you do NOT need dowels.

good luck,


howard coleman

NightmareSeven

iTrader: (9)

Do a search on ErnieT's car.At one point that guy was making 600+RWHP on a stock internal Reman Engine and never needed to Dowel Pin his motor,of course he's
making over 730+ now on a fully built motor.

Many guys on this fourm have reliably made
400-500+RWHP and never had any problems with not
having extra Pins in the engine block.They might be useful if you
continually have to put the engine under high stress as would have if your actively involved in racing or something.,even then you'd have to be putting down some serious HP.